The Premier One was the first of a line of state-of-the-art contenders to carry the conrad-johnson Premier badge.

Uncommonly powerful for a tube amplifier at 200 watts per channel, the Premier One was identified by one leading audiophile publication as the best sounding power amplifier ever made to that time.

An enormous power supply with massive computer-grade electrolytic capacitance totaling 4000 micro-farads at more than 500 volts delivered startling deep and controlled bass response not achieved by any other vacuum tube power amp. Ultralinear operation of the 6550 output stage offered an excellent combination of high power and low distortion. Complex loads were a breeze and hard to handle electrostatics speakers presented no problem to the Premier One.

Despite its brute power, the Premier One remained very delicate at the highest frequencies yielding extended high frequency response uncommon in vacuum tube designs and with a remarkably three dimensional soundstage. Premier Ones are sought after and highly prized by both collectors and audiophiles even today.

Premier 1 | Replacement Tube Set RTPR1

V1 & V2: 5751 | V3-V6: 6FQ7/6CG7 | V7-V18: 6550

Premier 1b | Replacement Tube Set RTPR1b

V1 & V2: 5751 | V3-V6: 6FQ7/6CG7 | V7-V18: EL34

Specifications:

• Power: 200 watts per channel into 4, 8, or 16ohms with no more than 1% THD and IM Distortion, both channels driven from 30 Hz to 15 kHz
• Frequency Response: 20Hz to 20kHz, +0, -.5dB
• Input Sensitivity: 1.0 volts to full power
• Hum & Noise: 100dB below full power
• Input Impedance: 100K ohms

Mechanical:

• Dimensions: 19w | 10.5h | 22d inches
• Weight: 135 lbs.

Owner’s Manuals

Premier One
Premier 1b

Designed as a companion for the Premier One, the Premier Two was noted for extended, controlled bass response, and very wide dynamic range.

Its three-dimensional soundstage set the Premier Two apart from its competition, leading to its top ranking in one noted publication’s survey of top preamps at the time.

Inputs/Outputs:

• 1 phono
• tuner
• auxiliary
• monitor and recording facilities for two tape decks with dubbing from Tape 1 to Tape 2
• two amplifier (main) outputs

Controls:

• selector
• tape 1/tape 2
• source/monitor
• mode (left, right, stereo, stereo reverse, mono)
• balance
• volume
• power
• mute

Premier 1 | Replacement Tube Set RTPR1

V1 & V2: 5751 | V3-V6: 6FQ7/6CG7 | V7-V18: 6550

Replacement Tube Set RTPR2

V1 & V2: 12AX7 | V3, V4, V6, V7, & V8: 5751 | V5 & V9: 5965 | V10: 12X4

Specifications:

• Gain: Phono Stage 40 dB (phono overload 500 mV at 1kHz) Line Stage 27 dB
• Distortion: less than .05% THD or IMD
• Response: bandpass 2Hz to more than 100kHz
• RIAA equalization +/- .25 dB (20 to 20 kHz)
• S/N Ratio: Phono Stage 72 dB below 10 mv input / Line Stage 84 dB below 2.5 volt output

Mechanical:

• Dimensions: 19w | 5.25h | 12.25d inches
• Weight: 21 lbs.

Owner’s Manual

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The Premier Three superseded the previous state-of-the-art Premier Two preamplifier.

This was the first preamplifier to feature the exclusive use of conrad-johnson’s proprietary CJD polystyrene film capacitors throughout the audio circuits and related power supplies.

This was an important factor in the Premier Three’s three dimensional soundstage, superior extended high frequency response, and ability to reproduce the “space” between instruments – sonic characteristics that earned the Premier Three the accolade as best sounding preamp of the decade in The Absolute Sound’s Tenth Anniversary issue.

The Premier Three-revision in 1986 involved upgrading the internal wiring to mono-crystal silver, and replacing the balance control with a stepped attenuator.

Inputs/Outputs:

• 1 phono
• tuner
• auxiliary
• monitor and recording facilities for two tape decks with dubbing from Tape 1 to Tape 2
• two amplifier (main) outputs

Controls:

• selector
• tape 1/Tape 2
• source/monitor
• mode (left, right, stereo, stereo reverse, mono)
• balance
• volume
• power
• mute

Replacement Tube Set RTPR3

V1 & V2: 12AX7 | V3, V4, V6, V7, & V8: 5751 | V5 & V9: 5965

Specifications:

• Gain: Phono Stage 40 dB (phono overload 500 mV at 1kHz)
• Line Stage 28 dB
• Distortion: less than .05% THD or IMD
• Response: bandpass 2Hz to more than 100kHz
• IRIAA equalization +/- .25 dB (20 to 20 kHz)
• S/N Ratio: Phono Stage 72 dB below 10 mv input / Line Stage 84 dB below 2.5 volt output

Mechanical:

• Dimensions: 19w | 5.25h | 12.25d inches
• Weight: 21 lbs.

Owner’s Manual

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The Premiere Four vacuum-tube power amplifier used two pair of EL34 output tubes per channel to produce 100 watts per channel.

It featured extensive use of conrad-johnson’s proprietary CJD polystyrene capacitors throughout the audio circuit and in the regulated power supplies for the voltage amplification stages.

The Premier Four achieved silky highs, and a remarkable three-dimensional soundstage.

Features

• 4, 8, 16 ohm speaker taps (screw type)
• one pair of input
• two plate fuses
• power switch
• built in bias indicators

Replacement Tube Set RTPR4

1 & V2: 5751 | V3 & V4: 6FQ7/6CG7 | V5-V12: EL34

Specifications:

• Power Output: 100 watts per channel, minimum RMS, at 4, 8, or16 ohms both channels driven from 30Hz to 15kHz with no more than 1% THD or IM Distortion.
• Response: 20Hz to 20kHz, +0, -.5dB
• Input Sensitivity: 1.0 volts to full power
• Input Sensitivity: 0.875 volts Hum & Noise: 96 dB below rated power

Mechanical:

• Dimensions: 19w | 9h | 20.5d inches
• Weight: 80 lbs.

Owner’s Manual

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The Premiere Five vacuum-tube power amplifier was similar in design to the Premier Four, but was a mono amplifier using eight EL34 output tubes to produce 200 watts.

Like the Premier Four, it featured extensive use of conrad-johnson’s proprietary CJD polystyrene capacitors throughout the audio circuit and in the regulated power supplies for the voltage amplification stages.

The Premiere Five was noted for its delivery of high-power into complex loads while maintaining a holographic, three-dimensional soundstage. Highs were unmatched in being delicate and extended.

Features

• 4, 8, 16 ohm speaker taps (screw type)
• one input
• two plate fuses
• power switch
• built in bias indicators

Replacement Tube Set RTPR5

V1: 5751 | V2 & V3: 6FQ7/6CG7 | V4-V11: EL34

Specifications:

• Power Output: 200 watts, minimum RMS, at 4, 8, or16 ohms from 30Hz to 15kHz with no more than 1% THD or IM Distortion.
• Response: 20Hz to 20 kHz, +0, -.5 dB
• Input Sensitivity: 1.0 volts
• Hum & Noise: 96 dB below rated power

Mechanical:

• Dimensions: 19w | 9h | 20.5d inches
• Weight: 80 lbs.

Owner’s Manual

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The Premier Six Pre-Preamplifier was conrad-johnson’s only Premier level pre-preamplifier.

Like the earlier HV1 and HV2, the Premier Six used nuvistors – small metal-enclosed triode vacuum tubes noted for their extraordinary linearity and low noise.

RF Filters and traps were judiciously executed to minimize noise and external interference, two things that made many other pre-preamps unacceptable in audiophile systems. Twin cascaded voltage regulators rejected AC line fluctuations and a separate regulator for the filament supply insured large dynamic range and excellent frequency response.

The final coupling capacitors were the “cjd” polystyrene capacitors and the power supply regulator had a lower source impedance. The outputs of the Premier Six were buffered to permit use with a wide range of interconnect cables.

Features

• one pair of RCA inputs
• one pair of RCA output jacks
• power switch

Replacement Tube Set RTPR6

V1-V4: 6CW4

Specifications:

• Input Impedance 2000 ohms (phono overload 200 mV at 1kHz)
• Gain: 28 dB
• Maximum Output: Greater than 5.0 volts into 50K load
• Distortion: less than .05% THD or IMD
• Response: bandpass 5Hz to more than 100kHz

Mechanical:

• Dimensions: 19w | 3.5h | 10.25d inches
• Weight: 6 lbs.

Owner’s Manual

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The Premier Seven was the first Zero-Feedback preamplifier from conrad-johnson.

It was a true dual-mono preamp design with a separate external regulated power supply for each channel. The result was a mammoth preamplifier, housed in four separate chassis.

Using 12 triodes (six per channel) in a zero feedback configuration provided extraordinary transient response not common in vacuum tube preamps. A low noise nuvistor input tube accommodated low output moving coil cartridges. A phono impedance selector was included for cartridge matching.

New standards of circuit components were used in the Premiere Seven, including 300 micron linear-crystal solid silver internal wiring. Each channel had its own level control. Instead of traditional potentiometers, the level controls are actually stepped attenuators which switch discrete pairs of precision resistors. Special laser trimmed metal foil resistors were used throughout the audio circuit.

The Premier Seven was stunning in its ability to resolve inner detail, recreate a huge dynamic range, and extended frequency response while presenting the soundstage with incomparable accuracy.

The Premier Seven-A offered a new phono stage circuit using a pair of nuvistors at the input. The resulting stage was even quieter, and capable of finer gradations in dynamics. The Premier Seven-B switched to machined oxygen free copper input/output jacks, upgraded internal wiring, and power supply resistors were upgraded to the same metal foil types used in the audio circuits.

Inputs/Outputs:

• 1 phono
• tuner
• auxiliary
• monitor and recording facilities for two tape decks with dubbing from Tape 1 to Tape 2
• two amplifier (main) outputs

Controls:

• source
• record
• level
• mute
• power

Premier Seven | Replacement Tube Set RTPREM7 (two channels)

each channel | V1: 6CW4 | V2-V6: 6GK5

Premier Seven-A, Seven-B | Replacement Tube Set RTPREM7A (two channels)

each channel | V1 & V2: 6CW4 | V3-V6: 6GK5

Specifications:

• Gain: Phono Stage 40 dB (phono overload 150 mV at 1kHz)
• Line Stage 29 dB
• Distortion: less than .25% THD or IMD
• Response: bandpass 2Hz to more than 100kHz
• RIAA equalization +/- .25 dB (20 to 20 kHz)
• S/N Ratio: Phono Stage 80 dB below 10 mv input
• Line Stage 88 dB below 2.5 volt output

Mechanical:

• Dimensions (control unit) 19w | 7h | 16 3/8″d inches
• Dimensions (power supply) 19″w | 3.5″h | 16″d inches
• Weight: 60 lbs.

Owner’s Manuals

Premier Seven
Premier 7a
Premier 7b

The flagship of the conrad-johnson amplifier line for many years, the Premier Eight was a powerful 275 watts per mono-block making it the perfect choice for speaker systems which require tremendous power input and control.

The Premier Eight used premium quality component parts throughout. The power supplies, including the main storage reservoir, used only polypropylene and “cjd” polystyrene capacitors as opposed to the traditional deployment of electrolytic capacitors.

The audio circuit consists of three stages. A triode- amplifier using four paralleled sections of two 5751’s amplifies the input signal. That stage is direct-coupled to a cathode coupled phase inverter, each half of which consists of four paralleled sections of two high current twin triodes. The phase inverter circuit provides a balanced, low-impedance drive to the final output stage ­ four pairs of 6550’s. They operate in AB ultra-linear configuration, offering an optimal combination of high-power, low distortion, and low output impedance.

The Premier Eight-A added a noise filter to the bias indicator circuit, upgraded resistors and capacitors in the voltage amplifier and bias power supplies, and improved input wiring. The Premier Eight-XS is a an Eight-A with output stage configured to use EL34s connected for triode operation.

All Premier Eights were supplied with a protective tube cover, especially important for households with small children and pets.

Features:

• 5-way binding post speaker connectors
• one pair of inputs
• two plate fuses
• power switch

Replacement Tube Set: RTPR8 or RTPR8XS

V1 & V2: 5751 | V3-V6: 6FQ7/6CG7 | V7-V18: 6550

Premier Eight and Premier Eight-A | V7-V18: EL34 Premier Eight-XS

Specifications:

• Power Output ­ 275 watts from 30Hz to 15kHz at no more than 1% THD or IMD into 4 ohms (also available connected for 2, 8 or 16 ohm loads).
• Power Output (model XS equipped with EL34 output tubes in triode mode) ­ 130 watts from 30Hz to 15kHz at no more than 1% THD or IMD into 4 ohms (also available connected for 2, 8 or 16 ohm loads).
• Response: 20Hz to 20kHz, +/- .1 dB
• Input Impedance: 100 kOhms
• Hum & Noise: 96 dB below rated power

Mechanical:

• Dimensions: 19w | 9.5h | 21d inches
• Weight: 90 lbs.

Owner’s Manual

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Premier Nine Vacuum Tube DAC

The Premier Nine features a “bit-stream” digital/analog converter stage. It accommodates the full 16 bit digital sample word, offering full resolution of all encoded information. Filtering and de-emphasis are performed in the digital domain to achieve a greater linear phase bandwidth. Third order noise shaping effectively attenuates a musical digital processing spuriae by 118dB, below the inherent digital noise floor.

Separate power transformers, separate regulated power supplies, and a shielded compartment isolate the analog stage from the digital circuitry.

All component parts are the finest conrad-johnson deploys. All capacitors are cjd polystyrene and all resistors are precision, laser-trimmed metal foil resistors.

Inputs:

• one ATT
• one TOS
• three Coaxial
• two RCA
• one BNC coaxial

Outputs:

• one pair of RCA main outputs
• one RCA Digital output

Controls:

• input selector
• phase-invert
• power

Replacement Tube Set RTPR9

V1 & V2: 6GK5

Specifications:

• Sensitivity 1.0 VRMS at 0dB maximum output
• Distortion: less than .05% THD or IMD
• Response: 5Hz to more than 20kHz
• Line Stage 92 dB below 1.0 volt output

Mechanical:

• Dimensions: 19w | 3h | 14d inches
• Weight: 30 lbs.

Owner’s Manual

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Premier Ten Line-Stage Vacuum Tube Pre-Amplifier

The Premier Ten was essentially two mono preamplifiers sharing a line cord and power transformer.

Specially constructed controls maintain a physical separation between channels to reduce capacitive-coupling and minimize crosstalk between channels. Individually regulated power supplies electrically isolate the two separate channels.

Derived directly from the Premier Seven, the audio circuit of the Premier Ten consists of a single triode amplifier direct coupled to a triode cathode follower. The low output impedance of the cathode follower permits the use of the Premier Ten with highly capacitive amplifier interconnect cables without attenuation of the high frequency information. The zero feedback circuit insures temporal accuracy and spatial detail.

The volume control is a 23 position switch selecting among 23 pairs of resistors ­ never more than a single-pair of resistors are inserted in the signal path by this control. The balance control is an 11 position switch that is electrically out of the circuit in the centered position. There are no carbon-track or conductive plastic resistive elements to degrade the audio signal in the Premier Ten.

Inputs:

• phono/aux
• tuner
• CD
• monitor and recording facilities for two tape decks with dubbing from Tape 1 to Tape 2

Outputs:

• one pair amplifier (RCA main) outputs

Controls:

• selector
• record (tape out selector)
• mute
• balance
• volume
• power

V1-V4: 6GK5

Specifications:

• Gain: 25 dB
• Maximum Output is 20 VRMS
• Distortion: less than .25% THD or IMD at 1.0 V output
• Response: bandpass 2Hz to more than 100kHz
• Phase: inverts phase of all inputs at main out
• Noise: 94 dB below 2.5 volt output

Mechanical:

• Dimensions: 19″W | 5.25″H | 16 3/8″D inches
• Weight: 28 lbs.

Owner’s Manual

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Premier Eleven Vacuum Tube Amplifier

Essentially a scaled down, stereo version of the Premier Eight, the Premier Eleven delivered 70 watts per channel from a single pair of 6550 output tubes.

The Premier Eleven used only the finest component parts in all stages including the power supply. The power supply used only polypropylene and “cjd” polystyrene capacitors as opposed to the traditional deployment of electrolytics. The main storage reservoir used polypropylene capacitors with polystyrene shunts.

The Eleven-A added a noise filter on the bias indicator circuit, first employed in the Premier Twelve. The Eleven-XS is an Eleven-A with the output stage configured to use a pair of EL34s operated as triodes.

Features:

• 5-way binding post speaker connectors
• one pair of inputs
• two plate fuses
• power switch

Replacement Tube Sets: RTPR11 or RTPR11XS

V1 & V2: 5751 | V3 & V4: 6FQ7/6CG7 | V5-V8: 6550

Premier Eleven, Eleven-A: V5-V8: EL34 ­ Eleven-XS

Specifications:

• Power Output ­ Ultralinear Operation: 70 watts per channel RMS at 4, 8, or16 ohms both channels driven from 30Hz to 15kHz with no more than 1% THD or IMD.
• Power Output ­ Triode Operation: 30 watts per channel RMS at 4, 8, or16 ohms both channels driven from 30Hz to 15kHz with no more than 1.5% THD or IMD.
• Frequency Response: 20Hz to 20 kHz, +0, -.1 dB
• Input Sensitivity: 0.9 volts to rated power
• Hum & Noise: 96 dB below rated power

Mechanical:

• Dimensions: 17.5W | 7.25H | 15D inches
• Weight: 48 lbs.

Owner’s Manual

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Premier Twelve Vacuum Tube Amplifier

The Premier Twelve is a mono-block tube power amplifier, in effect a smaller, lower powered version of the Premier Eight.

It used two pair of 6550s to produce 140 watts. It is similar in size and circuit to the stereo Premier Eleven. The Twelve-XS is a Twelve with the output stage configured to use a pair of EL34s operated as triodes to produce about 60 watts.

The Premier Twelve used only the finest component parts in all stages including the power supply. The power supply used only polypropylene and “cjd” polystyrene capacitors as opposed to the traditional deployment of electrolytics. The main storage reservoir used polypropylene capacitors with polystyrene shunts.

Features:

• 5-way binding post speaker connectors
• one pair of inputs
• two plate fuses
• power switch

Replacement Tube Sets: RTPR12 or RTPR12XS

Premier Twelve | V1: 5751 | V2 & V3: 6FQ7/6CG7 | V4-V7 6550

Premier Twelve-XS | V4-V7: EL34

Specifications:

• Power Output: Ultralinear Operation: 140 watts per channel RMS at 4, 8, or16 ohms both channels driven from 30Hz to 15kHz with no more than 1% THD or IMD.
• Power Output: Triode Operation: 60 watts per channel RMS at 4, 8, or16 ohms both channels driven from 30Hz to 15kHz with no more than 1.5% THD or IMD.
• Input Sensitivity: 0.90 volts to full power
• Hum & Noise: 98dB below full power
• Input Impedance: 100K ohms

Mechanical:

• Dimensions: 17.5W | 7.25H | 15D inches
• Weight: 48 lbs.

Owner’s Manual

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Premier Fourteen Remote Controlled Line-Stage Vacuum Tube Pre-Amplifier

The Premier Fourteen was the first preamp in the conrad-johnson Premier product line to offer remote control.

The Premier Fourteen introduced conrad-johnson¹s innovative volume control employing a micro-processor to select combinations from an array of metal-foil resistors. This produces a stepped attenuator with 100 steps in approximately .7 dB increments. By controlling the two channels independently, balance can also be adjusted in 0.7 dB steps. Only the highest quality resistors are introduced into the signal path by the level control, resulting in a noticeable improvement in sound quality.

The audio circuit of the Premier Fourteen consists of a single triode amplifier direct coupled to a triode cathode follower. The low output impedance of the cathode follower permits the use of the Premier Fourteen even installations with long, highly capacitive amplifier interconnect cables without attenuation of the high frequency information and without softening transients. A zero feedback circuit ensures temporal accuracy and spatial detail.

The premier Fourteen was selected by many audiophiles and major magazine reviewers for their own personal use due to its superlative handling of musical transients, its dynamic range, and its very wide frequency response. This is the ultimate complement for any piece of high-end audiophile equipment.

Inputs/Outputs:

• phono/aux1
• tuner
• CD
• video
• aux2
• two EPL loops for external processing or monitor and recording facilities
• one pair of main outputs

Controls:

• source selector
• EPL toggle
• level
• power
• sources and EPLs directly accessible by remote
• balance by remote.

Replacement Tube Set RTPR-14

4 X 6GK5s

Specifications:

• Gain: 25 dB
• Phase: Phase Inverting
• Maximum Output is 20 VRMS
• Distortion: less than .25% THD or IMD at 1.0 V output
• Response: bandpass 2Hz to more than 100kHz
• Line Stage 96 dB below 2.5 volt output
• Input Impedance: 100K ohms

Mechanical:

• Dimensions: 19W | 3.75H | 15.25D inches
• Weight: 23 lbs.

Owner’s Manual

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Premier Fifteen Vacuum Tube Phono Preamplifier

The Premier Fifteen phono equalization preamplifier provides the additional gain and equalization required for phono playback through a standard line-level preamplifier.

Designed to precisely track the prescribed RIAA equalization curve, the Premier Fifteen assures absolute tonal accuracy High gain circuits, carefully engineered for low noise, accommodate a wide range of moving coil and moving magnet cartridges.

The audio circuits of the Premier Fifteen are single-ended triode amplifiers (two per channel), with the final amplifier stage direct coupled to a triode cathode follower.

The low output impedance of the cathode follower permits the use of long, highly capacitive interconnect cables without attenuation of high frequency information and without softening of transients. The circuits are zero-feedback design, to eliminate the temporal inaccuracies that negative feedback introduces. Careful implementation of these fundamentally simple circuits results in extremely wide bandwidth, and low distortion, without resorting to negative feedback.

Power supply circuits present a parallel signal path to the audio circuits.

Ideally this signal path is merely a zero impedance path to ground. Any deviation from this ideal is fully reflected in the audio circuits. Thus the power supplies are as important to audio performance as the audio circuits and must be accorded equal attention in design. In the Premier Fifteen, each stage has its own discrete regulated DC power supply. These power supplies have been carefully designed for minimum impedance, even at the highest audio frequencies, to prevent the power supplies from degrading music reproduction.

The full potential of any circuit design can only be realized if executed with the highest quality parts.

The audio circuits of the Premier Fifteen use only conrad-johnson’s proprietary polystyrene capacitors. In the power supplies, all capacitors are polypropylene and polystyrene – there are no electrolytic capacitors anywhere in the audio circuits or their dc power supplies. The audio circuits and related power supplies both use high-precision laser trimmed metal-foil resistors, designed for ultra-low inductance. All parts in the Premier Fifteen’s RIAA compensation network are 1% tolerance, to assure precise tracking of the RIAA curve. Internal signal path wiring is exclusively of silver wire. Input and output connectors are gold-plated, machined oxygen free copper. All switching do functions are handled by sealed relays, featuring gold-plated silver contacts.

Thoughtful engineering, specification of the finest available component parts, and painstaking care taken in production make the Premier Fifteen an audio preamplifier system without peer in music reproduction. We invite you to arrange an audition with your conrad-johnson dealer to confirm for yourself the extraordinary musical performance of these products.

Specifications:

• Gain: 53 dB
• Phono Overload: 125mV
• Phono Equalization: within +/- .25 clB of RIAA
• Hum and Noise: 85 clB below 1OmV input
• Phase: phase correct
• Tube Complement: 6 12AX7, 2 6GK5

Mechanical:

• Dimensions: 19W | 3.315H | 15D inches
• Weight: 22 lbs.

Owner’s Manual

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conrad-johnson Premier Sixteen LS Remote Controlled Line-Stage Vacuum Tube Pre-Amplifier

In June of 1996, to commemorate twenty 20 years in the audio industry, conrad-johnson announced a limited edition preamplifier, the Anniversary Reference Triode (ART), which was designed to share our own in-house reference preamplifier with our colleagues and customers around the world. Very quickly, the ART has become widely held to be the finest sounding line-stage preamplifier in the world, with several reviewers noting that the limitations of this product could not be adequately perceived or characterized until other elements of their reference systems caught up. The ART, a massive dual-monaural unit, is inherently quite costly.

In an effort to provide musical performance closely approaching that of the ART to a wider audience of listeners, we offered the Premier Sixteen LS.

The Premier Sixteen LS is very nearly an ART compressed into a single chassis stereo unit.

Input selection and level adjustment are handled by an array of relays operating under microprocessor control. Level and balance can be adjusted in 100 steps of approximately .7 dB per step, with levels being set by precision, low noise metal foil resistors. All level setting and source selection functions can be controlled by the hand-held wireless remote control.

The circuitry of the Premier Sixteen LS Preamplifier is elegant in its simplicity.

The audio circuit consists entirely of a single triode amplifier stage. In this case the triode is actually a composite comprising six paralleled sections of high-transconductance miniature dual triodes. This arrangement achieves a suitably low output impedance while reducing the number of active stages to the absolute minimum of one, resulting in a sonic purity that is unparalleled. DC voltage is supplied to this stage by cascaded discrete voltage regulators designed to absolutely isolate the audio circuit from the power line by maintaining virtually zero impedance at all audio frequencies. To dramatically reduce infrasonic noise, tube filaments (heaters) are operated on a dc voltage supplied by a separate discrete regulated power supply

Considerable care and attention have been paid to the physical aspects of the design as well.

Microprocessor controlled relays, used for selecting sources, are located right at the input connectors keeping signal paths short to minimize crosstalk between channels and inputs. Critical audio circuitry is mounted on a subchassis which is isolated by a suspension system to reduce microphonics. The sturdy, all aluminum chassis is protected with a durable epoxy paint finish. Tubes are housed in an attractive cover outside the chassis, allowing easy access to the tubes for replacement by simply loosening two screws.

Parts quality is an exact match for the unprecedented level specified for the ART.

Each part is selected on the basis of both sonic performance and durability. All audio circuitry (including the level control) is executed entirely with precision metal foil resistors and polystyrene capacitors. Tubes have been carefully hand selected for minimum noise and microphonics. The dc regulated power supplies use the same type of metal foil resistors as the audio circuits. Capacitors for the audio circuit’s dc power supplies are exclusively polypropylene and polystyrene. Switching relays are sealed and have gold plated silver contacts. Input and output connectors are machined from oxygen free copper, and are gold plated by a special process that eliminates the use of magnetic materials. The Premier 16LS is built without compromise to achieve a new standard in musical performance, and it is built to last.

Replacement Tube Set RTPR-16

V1-V6: 6922

Specifications:

• Gain: 25 db
• Maximum output: 15 vrms
• Output impedance: under 700 ohms
• Distortion: less than .1% THD
• Frequency response: at unity gain: 2 Hz to more than 10OKhz
• Hum and noise: 96 db below 1.0 v

Mechanical:

• Dimensions: 19W | 3.75H | 15.25D inches
• Weight: 25 lbs.

Owner’s Manual

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Premier Seventeen LS Vacuum Tube Line Stage Preamplifier

AudioRevolution’s Best of 2002!

With the 1996 introduction of the Anniversary Reference Triode (ART), conrad-johnson established a benchmark for line-stage preamplifier performance.

Reviewers were unanimous in their praise, proclaiming it the finest sounding preamplifier ever manufactured. Some went so far as to assert that the ART’s limitations, if any, could not be perceived or characterized until the performance level of other audio components had reached a similarly advanced state.

There was just one problem with the limited edition ART, and that was that its massive dual-mono, two-chassis design was, by its very nature, expensive to manufacture. For the last several years conrad-johnson has dedicated itself to bringing the superlative performance of the ART to a broader audience. The Premier Seventeen LS is the fruit of that labor.

The Premier Seventeen LS is a an extremely simple design it employs the remarkable single-active-stage composite triode circuit introduced in the ART, which means the entire amplification circuit is a single active stage, without buffers or feedback.

Constructing the Premier Seventeen LS’ circuit from a composite triode consisting of four paralleled sections of high-transconductance miniature twin-triode tubes allows it to achieve a suitably low output impedance to drive practically any interconnect/amplifier combination while eliminating any circuit element that might compromise its sonic purity. Toward that end, the circuit is powered by discrete voltage regulators designed to completely isolate the audio signal from the power line.

The Premier Seventeen’s level control, like its input selection, utilizes microprocessor-controlled relays and a network of precision, low-noise metal foil resistors to effect loudness and balance changes in .7dB increments over 100 steps. This arrangement, plus a unity gain signal throughput, makes it simple to incorporate the Premier Seventeen LS into a high quality home theater system without compromising its two-channel performance. All switching and adjustment can be controlled by the unit’s remote control.

As with all Premier components, the Premier Seventeen LS is constructed from the highest quality, carefully selected parts for unrivaled sonic performance and reliability.

Only precision metal foil resistors and polypropylene and polystyrene capacitors are utilized in the audio circuitry (including the Premier Seventeen’s level control). The audio circuits and their related power supplies utilize low inductance, high-precision laser-trimmed metal foil resistors. Internal signal path wiring consists exclusively of silver wire, and input and output connectors are gold-plated oxygen free copper. Switches are sealed relays with gold-plated silver contacts.

In its quest to render the glory of music without compromise, conrad-johnson has dedicated itself to bridging the gulf between craft and art.

Through meticulous engineering, careful specification of only the finest available component parts, and a painstaking attention to construction, we have created what we feel is a pre-amplification system without rival in its class.

Specifications:

• Gain: 26 dB
• Maximum Output: 15 V rms
• Hum and Noise: 100 dB below 2.5 V output
• Distortion at 1.0V output: less than .1% THD or IMD
• Phase: inverts phase of all inputs at main output
• Output Impedance: less than 850 ohms

Mechanical:

• Dimensions: 19W | 3.315H | 15.25D inches
• Weight: 21 lbs.

Owner’s Manual

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Premier 18LS Solid-State Line Stage Preamplifier

The Premier 18LS is a reference quality line-level preamplifier and audio control center.

Flexible switching facilities and high-resolution balance and level controls make the Premier 18LS the ideal control center for high-end audio systems. A Theater mode, which passes the input signal through at unity gain, makes it simple to incorporate the Premier 18LS into a high quality home theater system without compromising two-channel performance. A full-featured remote control is a welcome added convenience. Above all, the Premier 18LS is a refined instrument designed to faithfully reproduce recorded music to recreate the emotional impact of live music.

A number of important elements of the circuit design merit special attention:

Field Effect Transistors (FETs).

More important than the total amount of distortion of an audio circuit is the character of the distortion. Odd-order harmonic distortion products, being musically unrelated to the fundamental tone, sound strident and irritating, whereas even-order distortion products are part of the natural musical overtones. FETs have been selected for the active devices in the Premier 18LS because, like tubes and unlike bi-polar transistors, they produce almost no odd-order harmonic distortion.

Zero Feedback.

Negative feedback is an engineering technique used to reduce measured distortion. While feedback does achieve this goal, it also introduces aberrations in the transient response characteristics of the circuit. The Premier 18LS uses conrad-johnson’s unique auto-linear gain block, which achieves low distortion with zero loop feedback by exploiting the symmetrical distortion properties of n and p channel FETs.

Solid Power Supplies.

Power supply circuits present a parallel signal path to the audio circuits. Ideally this signal path provides ac signals with a zero impedance path to ground. Any deviation from this ideal is reflected in the reproduced audio signal. Thus the power supplies are as important to audio performance as the audio circuits and must be accorded equal attention in design. The power supplies for the Premier 18LS feature discrete dc regulators that have been carefully designed for minimum impedance, even at the highest audio frequencies, to prevent the power supplies from degrading music reproduction.

Quality Parts.

As with all Premier components, the Premier 18LS is constructed from the highest quality, carefully selected parts for unrivaled sonic performance and reliability. Only precision metal foil resistors and polypropylene and polystyrene capacitors are utilized in the audio circuitry. The audio circuits and their related power supplies utilize precision low inductance laser-trimmed metal foil resistors. To avoid the compromised performance of a potentiometer, these same resistors are used in the level control, where level is set by to selecting combinations among an array of these resistors. Loudness and balance can be adjusted precisely in 100 steps of approximately .7dB per step. Even the precision-machined input/output connectors have been carefully selected for optimal sonic performance.

Thoughtful engineering, specification of the finest available component parts, and painstaking care taken in production make this an audio preamplifier without peer in music reproduction.

Specifications:

• Gain: 22 dB
• Maximum Output: 9 vrms
• Output Impedance: 200 Ohms
• Distortion: less than .1% THD
• Frequency Response: 2 Hz to 100 KHz
• Hum and Noise: line-stage 96 dB below 2.5 V
• Phase: phase inverting

Mechanical:

• Dimensions: 19W | 3.315H | 15.25D inches
• Weight: 16 lbs.

Owner’s Manual

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conrad-johnson Premier 140 Vacuum Tube Power Amplifier

The Premier series of conrad-johnson products are precision music reproduction instruments designed to meet the needs of audio industry professionals and other audiophiles who require near perfection from their reference systems.

The latest in the highly regarded Premier series of vacuum-tube power amplifiers, the Premier 140 is the proverbial iron hand in a velvet glove – capturing delicate textures and subtle nuances while demonstrating muscular power, authority and control.

The Premier 140 audio circuit consists of three stages.

The input signal is amplified by a single-ended triode amplifier designed for wide band-width. The signal is then direct coupled to a cathode coupled phase-inverter. This high current, triode phase-inverter stage provides a balanced, low impedance drive to the output stage. Output power is developed by two pairs of 6550s per channel, chosen for their excellent sonic character, high power, and reliability. The output tubes are operated in ultralinear configuration which offers a desirable combination of high power and low distortion. Massive output transformers with intricately interleaved windings afford extended bandpass and high phase linearity. A small amount (about 12 dB) of loop negative feedback reduces distortion and achieves a sufficiently high damping factor to control reactive loudspeaker systems.

Power supply design is every bit as critical to the performance of an audio component as the audio circuit itself.

In the Premier 140, separate, low impedance, discrete dc power supply regulators are provided for the input and phase-inverter stages, preventing the output stage from modulating these stages through the power supply The main power supply reservoir uses a bank of massive custom polypropylene capacitors. No electrolytic capacitors are used in any of these power supplies.

The Premier amplifiers require no complicated adjustments or specialized equipment to maintain. To assure continued peak performance, the owner need only make a simple bias adjustment when new tubes are installed. Built in LED bias indicators allow the user to make this adjustment using only the supplied screwdriver.

At conrad-johnson we are keenly aware that component parts contribute importantly to the sonic performance of any circuit design.

The Premier 140 amplifier maintains the exacting quality standards for which conrad-johnson is internationally known. Resistors are precision tin-oxide deposited on glass and bulk metal foil. All audio-circuit capacitors are polystyrene, while the power supplies use large value polypropylene in parallel with polystyrene capacitors. There are no electrolytic capacitors in the audio circuits or in the related power supplies. Proprietary wide-bandwidth output transformers contribute to excellent high frequency performance. Even the machined gold plated OFC connectors and the internal wiring have been carefully selected for optimal sonic performance. Attention to details of this kind enable us to extract the full potential from our circuit designs and ensure that our products will perform to this potential for years to come.

Specifications:

• Power: 140 watts RMS per channel both channels driven into 4, 8, or 16 ohms (depending on configuration, default is configured for 4 ohms) from 30Hz to 15KHz at no more than 1.5% total harmonic distortion or
  intermodulation distortion.
• Sensitivity: 1.1 volts rms to rated power.
• Gain: 27 dB
• Small Signal Distortion: Less than .1% at midband
• Phase: Phase correct (non-inverting)
• Frequency response: 20Hz to 20KHz +0, -.5dB
• Hum and noise: 104dB below rated power output
• Input impedance: 100K ohms.

Mechanical:

• Dimensions: 19W | 8H | 19D inches
• Weight: 85 lbs.

Owner’s Manual

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Premier 350 Solid State Amplifier

The Premier series of conrad-johnson products are precision music reproduction instruments designed to meet the needs of audio industry professionals and other audiophiles who require near perfection from their reference systems. The Premier 350 is a high-power amplifier with plenty of muscle to control any loudspeaker system, yet capable of capturing the delicate textures and subtle nuances of live music performances.

Hybrid Solid-State Circuit

The Premier 350 benefits from an interesting hybrid of solid-state technologies. The distortion characteristics of an amplifier are dominated by it’s voltage gain stage. We have selected FETs for this application, because, like tubes, and unlike bi-polar transistors, they produce almost no strident odd-order harmonic distortion. The output stage of an amplifier must efficiently couple the high amplitude signal produced by the voltage gain stage to the loudspeaker system to assure the power and control needed to produce a musically accurate response. Bi-polar devices have been specified for the output stages of these amplifiers because they offer about 1/4th the output impedance of a MOSFET, resulting in much better control of the loudspeaker. This is most noticeable in faster, more solid bass response.

Zero Feedback

Negative feedback is an engineering technique used to reduce measured distortion. While feedback does achieve this goal, it also introduces aberrations in the tran-sient response characteristics of the circuit. The Premier 350 uses conrad-johnson’s unique auto-linear gain block for the voltage gain stage, which achieves low distortion with zero loop feedback by exploiting the symmetrical distortion properties of n and p channel FETs.

Solid Power Supplies

Power supply circuits present a parallel signal path to the audio circuits. Ideally this signal path provides ac signals with a zero impedance path to ground. Any deviation from this ideal is reflected in the reproduced audio signal. Thus the power supplies are as important to audio performance as the audio circuits and must be accorded equal attention in design. The Premier 350 features a discrete dc regulators to power the critical voltage gain stage.

Quality Parts

As with all Premier components, the Premier 350 is constructed from the highest quality, carefully selected parts for unrivaled sonic performance and reliability. The circuits employ polypropylene and polystyrene capacitors extensively, except in the main power supply storage, where special high-speed electrolytics are used because of the extremely high capacitance required. The audio circuit and related power supplies utilize precision low inductance laser-trimmed metal foil resistors. The obsession for parts quality extends to the high quality, gold plated input jacks and output connectors – even the internal wiring is chosen on the basis of its sound quality in its specific application.

Thoughtful engineering, specification of the finest available component parts, and painstaking care taken in production make this an audio amplifier without peer in music reproduction.

Specifications:

• Output Power: 350 watts per channel from 20 Hz to 20 KHz at no more than 1.0 % THD or IMD, both channels driven into 8 ohms.
• Frequency response: (at 10 watts): 20 Hz to 20 kHz, +/- .1 dB
• Hum and noise: 104 dB below rated power
• Sensitivity: 1.1 volt rms to rated power
• Input Impedance: 100 KOhms

Mechanical:

• Dimensions: 19W | 8H | 16.375D inches
• Weight: 84 lbs.

Reviews

Soundstage
Stereo Times
Tone Audio

Owner’s Manual

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ART – Anniversary Reference Triode Preamplifier

In celebration of twenty years in pursuit of perfection in the reproduction of recorded music, conrad-johnson introduced the Anniversary Reference Triode Preamplifier.

This remarkable unit is a production realization of a line-stage preamplifier originally designed exclusively for our own reference use. The final production implementation of this design is aesthetically striking, ergonomically appealing to use, and quite simply the best-sounding line stage we have ever heard. We expect it to serve as our own reference for many years to come. The ART Preamplifier was available in a numbered, limited edition of 250 units which were sold through selected conrad-johnson dealers

The ART Preamplifier is a vacuum-tube, line-stage preamplifier in a true dual-mono configuration, with completely separate right and left chassis.

The unit features input selection and level adjustment by microprocessor- controlled relays. A data link, which is isolated from the audio circuitry and grounds of the two channels, connects the two chassis to enable a single set of controls to operate both channels, eliminating the bothersome dual volume controls that are the bane of conventional dual-mono designs. Level and balance can be adjusted in 100 steps of approximately .66 dB per step. All functions can be controlled by the hand-held wireless remote control.

The circuitry of the ART Preamplifier is elegant in its simplicity.

The audio circuit consists entirely of a single amplifier stage incorporating one composite triode comprising ten paralleled sections of high-transconductance miniature dual triodes. This arrangement achieves a low output impedance while reducing the number of active stages to the absolute minimum of one, resulting in a sonic purity that is unparalleled . DC voltage is supplied to this stage by cascaded discrete voltage regulators that absolutely isolate the audio circuit from the power line by maintaining virtually zero impedance across the audio band. Tube filaments (heaters) are operated on a dc voltage supplied by another discrete regulated power supply

Of course, the full potential of any circuit can only be realized by using the finest available parts.

In the ART Preamplifier, the audio circuit (including the level control) is executed entirely with precision bulk metal foil resistors and polystyrene capacitors. Tubes have been carefully selected for minimum noise and micro-phonics. The dc regulated power supplies use the same quality resistors as the audio circuits, and poly-propylene and polystyrene capacitors. Switching relays are sealed and have gold plated silver contacts. Input and output connectors are machined from oxygen free copper, and are gold plated. The component parts selected for the ART Preamplifier not only contribute to its unmatched musical performance today, but will help assure that this performance can be sustained year after year.

Replacement Tube Set RTART

V1-V10: 6922

Specifications:

• Gain: 25 db
• Maximum output: 15 vrms
• Output impedance: under 700 ohms
• Distortion: less than .1% THD
• Frequency response: at unity gain: 2 Hz to more than 10OKhz
• Hum and noise: 96 db below 1.0 v

Mechanical:

• Dimensions: 19W | 3.315H | 15.25D inches, each chassis
• Weight: 50 lbs.

Owner’s Manual

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ACT2 preamplifier

The ACT2 preamplifier embodies conrad-johnson’s latest advances in line-stage preamplifier technology.

It is the successor to the legendary ART preamplifier that has been widely recognized as the reference standard for line-stage preamplifiers since its introduction in 1996. The ACT2 incorporates the breakthrough concept of the composite triode circuit (which has garnered more than a dozen international awards for conrad-johnson preamplifiers). The ACT2 refines this approach by implementing circuit upgrades and by taking advantage of recent advances in materials technologies. The end result is a line-stage preamplifier that we believe will quickly be recognized as the new industry-wide reference standard.

The ACT2 Preamplifier is a vacuum-tube, line-stage preamplifier that looks as good as it sounds.

It is also notable for convenience and ease of use. The unit features input selection and level adjustment by microprocessor-controlled relays. Level and balance can be adjusted in 100 steps of approximately .7 dB per step. All functions can be controlled by the hand-held wireless remote control.

The circuitry of the ACT2 Preamplifier is elegant in its simplicity.

The audio circuit consists entirely of a single amplifier stage incorporating one composite triode comprised of four paralleled sections of ultra-high transconductance miniature dual triodes. This arrangement achieves a low output impedance while reducing the number of active stages to the absolute minimum of one, resulting in unparalleled sonic purity. DC voltage is supplied to this stage by cascaded discrete voltage regulators that absolutely isolate the audio circuit from the power line by maintaining virtually zero impedance across the audio frequency band. Infrasonic noise is minimized by operating the tube filaments (heaters) on a dc voltage supplied by another discrete regulated power supply.

Considerable care and attention have been paid to the physical aspects of the design as well.

Microprocessor controlled relays, used for selecting sources and level setting, are located right at the input connectors, keeping signal paths short to minimize crosstalk between channels and inputs. Critical audio circuitry is mounted on a subchassis that is isolated by a suspension system designed to minimize microphonics. The dramatic casework features an attractive clear Lucite tube guard outside the chassis, allowing for easy access for tube replacement.

At conrad-johnson we have long appreciated that the full potential of any circuit can only be realized by using the finest available parts.

Each part for the ACT2 has been selected on the basis of both sonic performance and durability. The audio circuit (including the level control) is executed entirely with precision metal foil resistors and Teflon and polystyrene capacitors. Tubes have been carefully hand selected for minimum noise and microphonics. The dc regulated power supplies use the same quality resistors as the audio circuits. Capacitors for the power supplies are exclusively polypropylene, polystyrene, and Teflon – there are no electrolytic capacitors in the audio circuits or their related power supplies. Switching relays are sealed and have gold plated silver contacts. Input and output connectors are machined from oxygen free copper, and are gold plated.

The ACT2 is built without compromise to achieve a new standard in musical performance, and it is built to last.

Specifications:

• Gain: 21.5 db
• Maximum output: 10 vrms
• Output impedance: under 500 ohms
• Distortion: less than .1% THD
• Frequency response: at unity gain: 2 Hz to more than 10OKhz
• Hum and noise: 100 db below 1.0 v
• Tube complement: 4 x 6N30P

Mechanical:

• Dimensions: 19W | 5.375H | 5.75D inches
• Weight: 30 lbs.

Owner’s Manuals

ACT2
ACT2s2

Introduced in 1977 by Bill Conrad and Lew Johnson, the conrad-johnson preamplifier, later designated the PV1, was an important factor in the revival of the preeminence of vacuum-tube audio components in high-end audio.

Already with their first product, conrad-johnson was emphasizing the critical importance of the quality of component parts. The original PV1 literature noted the use of “metal film resistors and polyester and silvered mica capacitors”. Critics of the day regarded the PV1 to be one of the best sounding preamps at the time, particularly noting its natural reproduction of musical harmonics.

Built on a rugged chassis with a robust power supply, a great many PV1’s are still in use today!

Replacement Tube Set RT1

V1, V2, V3, & V6: 12AX7 | V4 & V5: 5751

Features:

Inputs/Outputs

• 2 Phonos
• Tuner
• Auxiliary
• Monitor and recording facilities for two tape decks with dubbing from Tape 1 to Tape 2
• Two power amplifier (main) outputs

Controls:

• Selector
• Source/Monitor
• Mode (Left/Right/Stereo/Reverse/Mono)
• Balance
• Volume
• Power

Specifications:

• Gain: Phono Stage 35 dB (phono overload 500 mV at 1kHz)
• Line Stage 28 dB
• Distortion: less than .05% THD or IMD
• Response: bandpass 2Hz to more than 100kHz
• RIAA Equalization: +/- .25 dB (20 to 20 kHz)
• S/N Ratio: Phono Stage 70 dB below 10 mv input
• Line Stage 84 dB below 2.5 volt output
  
• Phase: Phono Stage is phase correct, Line Stage is phase correct

Mechanical:

• 14 x 4 3/4″ x 11 1/4

Owner’s Manual

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The PV2 was a refinement of the PV1.

The PV2 offered a similar circuit with the more linear 5751 substituted for the second triode in the phono stage and 12AT7s used as cathode followers for lower output impedance. The PV2 was constructed on a single main pc-board, eliminating the cumbersome wiring harnesses of the PV1, and assuring unit-to-unit consistency in production. The PV2 maintained or improved the parts quality standards established in the PV1.

A muting circuit was added to mute the turn-on and turn-off surges associated with tube preamplifiers.

Replacement Tube Set RT2

V1: 12AX7 | V2, V5: 5751 | V3, V4, V6: 12AT7

Features:

Inputs/Outputs

• 2 Phonos
• Tuner
• Auxiliary
• Monitor and recording facilities for two tape decks with dubbing from Tape 1 to Tape 2
• Two power amplifier (main) outputs

Controls:

• Selector
• Source/Monitor
• Mode (Stereo/Reverse/Mono)
• Balance
• Volume
• Power
• Auto-muting to suppress warm up transients

Specifications:

• Gain: Phono Stage 34.5 dB (phono overload 500 mV at 1kHz)
• Line Stage 24.5 dB
• Distortion: less than .05% THD or IMD
• Response: bandpass 2Hz to more than 100kHz
• RIAA Equalization: +/- .25 dB (20 to 20 kHz)
• S/N Ratio: Phono Stage 70 dB below 10 mv input
• Line Stage 84 dB below 2.5 volt output
• Phase: Phono Stage is phase correct, Line Stage is phase correct

Mechanical:

• 14″ X 3 13/16″ x 10″

Owner’s Manual

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The PV3 was the first vacuum tube preamp available as a kit since the 1960s.

Priced at $399 Assembled or $299 Kit, the PV3 was the ideal choice for those who loved music but were faced with the realities of a low cost budget. Cost was kept low by minimizing features, not compromising quality. The RIAA circuit used 1% tolerance parts and metal film resistors were used in critical parts of the circuitry.

The PV3 delivered the tonal balance and dynamics that conrad-johnson was now famous for.

Replacement Tube Set RT3

V1, V2, & V3: 12AX7 | V4: 12AT7

Features:

Inputs/Outputs

• Phono
• Tuner
• One Tape recorder with monitor and recording facilities
• One main output

Controls:

• Volume (dual concentric)
• Source/Monitor
• Phono/Tuner
• Power

Specifications:

• Gain: Phono Stage 38 dB (phono overload 500 mV at 1kHz)
• Line Stage 26 dB
• Distortion: less than .05% THD or IMD
• Response: bandpass 10Hz to more than 100kHz
• RIAA Equalization: +/- .5 dB (20 to 20 kHz)
• S/N Ratio: Phono Stage 70 dB below 10 mv input
• Line Stage 84 dB below 2.5 volt output
  
• Phase: Line Stage phase inverting, Phono Stage (at tape-out) phase correct

Mechanical:

• 10″ x 3″ x 7″

Owner’s Manual

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The PV4, was considered “affordable excellence” by many budget minded audiophiles.

It achieved its low price by eliminating all but essential features, not by seriously compromising the quality of component parts. The PV4 used precision low noise metal film resistors and polypropylene and polystyrene capacitors. All of the selectors and controls were chosen to yield smooth trouble free performance and unit-to-unit consistency.

The phono stage of the PV4 resembled that of the PV2AR using two triodes for voltage gain and one as a cathode follower. The line stage was a unique design with one triode for voltage gain direct coupled to the cathode follower output stage.

Replacement Tube Set RT4

V1, V2, & V4: 12AX7 | V3 & V5: 12AT7

Features:

Inputs/Outputs

• Phono
• Tuner
• One Tape recorder with monitor and recording facilities
• One main output

Controls:

• Volume
• Balance
• Source/Monitor
• Phono/Tuner
• Power

Specifications:

• Gain: Phono Stage 38 dB (phono overload 500 mV at 1kHz)
• Line Stage 18 dB
• Distortion: less than .1% THD or IMD
• Response: bandpass 2Hz to more than 100kHz
• RIAA Equalization: +/- .25 dB (20 to 20 kHz)
• S/N Ratio: Phono Stage 70 dB below 10 mv input
• Line Stage 84 dB below 2.5 volt output
• Phase: Line Stage phase inverting, Phono Stage phase correct

Mechanical:

• 13″ X 4″ x 9″

Owner’s Manual

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The PV5 was a completely new preamp in all areas.

The sophisticated circuitry allowed the PV5 to outperform preamps nearly three times it price. The PV5 was the personal choice as a reference preamp for many audio reviewers at the time!

Low noise mil-spec resistors and polypropylene capacitors were used throughout the PV5 and the famous “CJD” polystyrene capacitors were used throughout the signal path.

Their wide bandwidth and low sonic “memory” permitted precise attack and decay of musical transients. RIAA phono equalization was set with 1% tolerance parts. Eight factory burned-in vacuum tubes were used in the PV5.

Replacement Tube Set RT5

V1 & V2: 12AX7 | V3, V5, V6, & V7: 5751 | V4 & V8: 5965

Features:

Inputs/Outputs

• Phono
• Tuner
• Auxiliary
• Tape1 and Tape2 recorder inputs with monitor and recording facilities
• Two main outputs
• Auto-muting to suppress warm up transients

Controls:

• Selector
• Tape 1/Tape 2
• Source/Monitor
• Mode (Stereo/Reverse/Mono/Left/Right)
• Balance
• Power
• Volume

Specifications:

• Gain: Phono Stage 41.5 dB (phono overload 500 mV at 1kHz)
• Line Stage 28.5 dB
• Distortion: less than .05% THD or IMD
• Response: bandpass 2Hz to more than 100kHz
• RIAA Equalization: +/- .25 dB (20 to 20 kHz)
• S/N Ratio: Phono Stage 72 dB below 10 mv input
• Line Stage 84 dB below 2.5 volt output
• Phase: Line Stage phase correct, Phono Stage phase correct

Mechanical:

• 16″ X 3″ x 10″

Owner’s Manual

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The PV6 was a refinement of the earlier PV2ar design with improved resistor and capacitor selections.

The PV6 used upgraded precision low noise resistors and polypropylene capacitors. The result was superior definition and depth of imaging. The phono section was noticeably quieter than earlier designs.

Replacement Tube Set RT6

V1: 12AX7 | V2, V4 & V5: 5751 | V3 & V6: 12AT7

Features:

Inputs/Outputs

• Phono
• Tuner
• Auxiliary
• Monitor and recording facilities for two tape decks with dubbing from Tape 1 to Tape 2
• Two main outputs
• Auto-muting to suppress warm up transients

Controls:

• Selector
• Source/Monitor
• Mode (Reverse, Stereo, Mono)
• Balance
• Volume
• Power

Specifications:

• Gain: Phono Stage 38.5 dB (phono overload 500 mV at 1kHz)
• Line Stage 28.5 dB
• Distortion: less than .05% THD or IMD
• Response: bandpass 2Hz to more than 100kHz
• RIAA Equalization: +/- .25 dB (20 to 20 kHz)
• S/N Ratio: Phono Stage 72 dB below 10 mv input
• Line Stage 84 dB below 2.5 volt output
• Phase: Line Stage phase correct, Phono Stage phase correct

Mechanical:

• 14″ X 4″ x 10″

Owner’s Manual

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Successor to the PV6, the PV7 is a dramatic demonstration of the excellent results obtainable with simple circuits that are carefully executed.

A single triode voltage amplifier was used in the line stage (high level) directly coupled to the cathode follower. This design required only one capacitor in the line stage signal path greatly reducing the distortions and non-linearities associated with more complex designs. The phono section was noticeably quieter than earlier designs.

The PV7 offered superior definition and depth of imaging at a modest price. The conrad-johnson look and feel was evident in the PV7.

Replacement Tube Set RT7

V1, V2, & V4: 12AX7 | V3 & V5: 12AT7

Features:

Inputs/Outputs

• Phono
• Tuner
• Auxiliary
• Monitor and recording facilities for two tape decks with dubbing from Tape 1 to Tape 2
• Two main outputs
• Auto-muting to suppress warm up transients

Controls:

• Selector
• Tape 1/Tape 2
• Source/Monitor
• Mode (Reverse, Stereo, Mono)
• Balance
• Volume
• Power

Specifications:

• Gain: Phono Stage 40 dB (phono overload 500 mV at 1kHz)
• Line Stage 20 dB
• Distortion: less than .1% THD or IMD
• Response: bandpass 2Hz to more than 100kHz
• RIAA Equalization: +/- .25 dB (20 to 20 kHz)
• S/N Ratio: Phono Stage 72 dB below 10 mv input
• Line Stage 84 dB below 2.5 volt output
• Phase: Line Stage phase inverting, Phono Stage phase correct

Mechanical:

• 14 1/2″ X 3″ x 10″

Owner’s Manual

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The PV8 superceded the PV5.

It was the first all-tube zero-feedback design from conrad-johnson.

The basic audio circuit of the PV8 is modular, built from individual gain blocks consisting of a triode amplifier direct coupled to a cathode follower.

The phono stage consists of a gain block, a passive RIAA network, and a second gain block. The line stage consists of a single gain block. These stages use polypropylene capacitors bypassed by a polystyrene capacitor for the output stages. Even the main dc power supplies used polypropylene capacitors – there are no electrolytic capacitors in the audio circuits or their related power supplies. Paralleled triode sections at the phono input yield nearly 3 dB improvements in the signal to noise ratio over a single input tube (as used in the earlier PV5).

Replacement Tube Set RT8

V1 & V2: 12AX7 | V3 & V5: 5751 | V4 & V6: 5965

Features:

Inputs/Outputs

• Phono
• Tuner
• Auxiliary
• Monitor and recording facilities for two tape decks with dubbing from Tape 1 to Tape 2
• One main output
• Auto-muting to suppress warm up transients

Controls:

• Selector
• Tape 1/Tape 2
• Source/Monitor
• Mode (Reverse, Stereo, Mono)
• Balance
• Volume
• Power

Specifications:

• Gain: Stage 47 dB (phono overload 200 mV at 1kHz)
• Line Stage 31 dB
• Distortion: less than .1% THD or IMD
• Response: bandpass 2Hz to more than 100kHz
• RIAA Equalization: +/- .25 dB (20 to 20 kHz)
• S/N Ratio: Phono Stage 76 dB below 10 mv input
• Line Stage 85 dB below 2.5 volt output
• Phase: Line Stage phase inverting, Phono Stage phase correct

Mechanical:

• 19″ X 3″ x 12″

Owner’s Manual

download

The PV9, also an all-tube zero-feedback design offered a step up from the PV8.

The basic audio circuit of the PV9 is essentially modular, built from individual gain blocks consisting of a triode amplifier direct coupled to a cathode follower. The phono stage consists of a gain block, a passive RIAA network, and a second gain block. The line stage consists of a single gain block. Both phono and line stages used pure polystyrene capacitors exclusively, including the large output coupling capacitors.

The PV9a substituted 6FQ7s for the cathode follower tubes for lowered source impedance.

Replacement Tube Set RT9

V1 & V2: 12AX7 | V3, V4, & V6: 5751 | V5 & V7: 5965

Replacement Tube Set RT9a

V1 & V2: 12AX7 | V3 & V5: 5751 | V4 & V6: 6FQ7

Features:

Inputs/Outputs

• Phono
• Tuner
• Auxiliary
• Monitor and recording facilities for two tape decks with dubbing from Tape 1 to Tape 2
• Two main outputs
• Auto-muting to suppress warm up transients

Controls:

• Selector
• Tape 1/Tape 2
• Source/Monitor
• Balance
• Volume
• Power

Specifications:

• Gain: Stage 47 dB (phono overload 200 mV at 1kHz)
• Line Stage 31 dB
• Distortion: less than .1% THD or IMD
• Response: bandpass 2Hz to more than 100kHz
• RIAA Equalization: +/- .25 dB (20 to 20 kHz)
• S/N Ratio: Phono Stage 79 dB below 10 mv input
• Line Stage 85 dB below 2.5 volt output
• Phase: Line Stage phase inverting, Phono Stage phase correct

Mechanical:

• 19″ X 5″ x 14″

Owner’s Manual

PV9
PV9a

The PV10 drew on the technology of conrad-johnson’s path-breaking Premier Seven to achieve musical performance beyond its modest price.

Both the phono and line stages are zero feedback design. The phono section uses two triode amplifiers separated by a passive RIAA equalization network.

The PV10A revision featured a new line stage circuit based on two 12AU7s. A bit more than a year after the introduction of the PV10A, a line-stage only version was offered — the PV10AL. There have been three variants of the PV10A and AL. The first had the same control set as the PV10, as listed below. The second used a new balance control, with a detented center position that was out of the circuit. The balance enable/disable switch was deleted. The final version of the PV10A and AL deleted the balance control. Aside from these changes, and associated cosmetic revisions, the three versions are all identical in circuitry.

Replacement Tube Set RT10

V1 & V2: 12AX7 | V3 & V5: 12AT7 | V4: 5751

Replacement Tube Set RT10A

V1 & V2: 12AX7 | V3: 12AT7 | V4 & V5: 12AU7

Replacement Tube Set RT10AL

V1, V2 & V3: unused | V4 & V5: 12AU7

Features:

Inputs/Outputs

• Phono
• Tuner
• CD
• Video
• Auxiliary
• One Tape input with monitor and recording facilities
• One main output
• Auto-muting to suppress warm-up transients

Controls:

• Selector
• Source/Monitor
• Balance (deleted in last version of PV10A and AL)
• Balance In/Out (deleted in later versions of PV10A and AL)
• Volume
• Power

Specifications:

• Gain: Phono Stage 48.5 dB (phono overload 125 mV at 1kHz)
• 31.5 dB (18 dB for PV10A and PV10AL)
• Distortion: less than .1% THD or IMD
• Response: bandpass 2Hz to more than 100kHz
• RIAA Equalization: +/- .25 dB (20 to 20 kHz)
• S/N Ratio: Phono Stage 72 dB below 10 mv input
• Line Stage 84 dB below 2.5 volt output
• Phase: Line Stage phase inverting, Phono Stage phase correct

Mechanical:

• 16″ X 3″ x 11″

Owner’s Manuals

PV10
PV10a

The PV10B (with phono stage) and PV10BL (line-stage only) offered refinements to the circuitry of the PV10A.

Improvements included incorporating the line stage circuit of the PV12A that eliminated local feedback from the voltage gain stage. The PV10B also featured addition of “bypass” capacitors in parallel with critical power supply and audio circuit capacitors, and upgrading several resistors in the power supplies.

Both the phono and line stages continued to be zero feedback design. The phono section uses two triode amplifiers separated by a passive RIAA equalization network.

Replacement Tube Set RT10B

V1 & V2: 12AX7 | V3 12AT7 | V4 & V5: 6189

Replacement Tube Set RT10BL

V1 & V2: unused | V3: unused | V4 & V5: 6189

Features:

Inputs/Outputs

• Phono
• Tuner
• CD
• Video
• Auxiliary
• One Tape input with monitor and recording facilities
• One main output
• Auto-muting to suppress warm-up transients

Controls:

• Selector
• Source/Monitor
• Volume
• Power

Specifications:

• Gain: Phono Stage 48.5 dB (phono overload 125 mV at 1kHz)
• Distortion: less than .1% THD or IMD
• Response: bandpass 2Hz to more than 100kHz
• RIAA Equalization: +/- .25 dB (20 to 20 kHz)
• S/N Ratio: Phono Stage 75 dB below 10 mv input
• Line Stage 92 dB below 2.5 volt output
• Phase: Line Stage — phase inverting, Phono Stage — phase correct

Mechanical:

• 16″ X 3″ x 11″

Owner’s Manual

download

Successor to the PV8, the PV11 advanced the conrad-johnson zero feedback approach to elicit the ultimate in dynamic contrasts and spatial information.

An improved line stage circuit, incorporating two 12AU7s was introduced in the PV11. Like the PV8, the PV11 features the exclusive use of polypropylene and polystyrene capacitors throughout the audio circuits and related power supplies — no electrolytics are used, even in the main power supply input filter.

The PV11L is a line stage version of the PV11 (without phono stage).

Replacement Tube Set RT11

V1 & V2: 12AX7 | V3: 5751 | V4, V5 & V6: 12AU7

Replacement Tube Set RT11L

V1, V2, V3 & V4: unused | V5, & V6: 12AU7

Features:

Inputs/Outputs

• Phono
• Tuner
• Auxiliary
• Tape 1/Tape 2
• Two main outputs

Controls:

• Selector
• Tape 1/Tape 2
• Source/Monitor
• Mode (Left, Right, Stereo, Reverse, Mono)
• Balance
• Power
• Level

Specifications:

• Gain: Phono Stage 47 dB (phono overload 200 mV at 1kHz)
• Line Stage: 18 dB
• Distortion: less than .1% THD or IMD
• Response: bandpass 2Hz to more than 100kHz
• RIAA Equalization: +/- .25 dB (20 to 20 kHz)
• S/N Ratio: Phono Stage 78 dB below 10 mv input
• Line Stage 92 dB below 2.5 volt output
• Phase: Line Stage phase inverting, Phono Stage phase correct

Mechanical:

• 16″ X 3″ x 12.5″

Owner’s Manual

download

The PV-12 superseded the PV11.

Like its predecessor, it featured zero feedback circuits, and passive equalization in the phono stage. For the PV12, critical plate resistors are a special laser-trimmed metal foil type chosen for their extremely low noise and low inductance. The balance control is an eleven-step switch incorporating discrete resistors.

The PV-12L is a line stage version of the PV-12 without the phono section.

Replacement Tube Set RT12

V1 & V2: 12AX7 | V3: 5751 | V4, V5 & V6: 12AU7

Replacement Tube Set RT12AL

V1, V2, V3 & V4 unused. | V5 & V6: 12AU7

Features:

Inputs/Outputs

• Phono
• Tuner
• Auxiliary
• Monitor and recording facilities for two tape decks
• One main output

Controls:

• Source Selector
• Record Out Selector
• Balance
• Volume
• Power

Specifications:

• Gain: Phono Stage 47 dB (phono overload 200 mV at 1kHz)
• Line Stage: 18 dB
• Distortion: less than .1% THD or IMD
• Response: bandpass 2Hz to more than 100kHz
• RIAA Equalization: +/- .25 dB (20 to 20 kHz)
• S/N Ratio: Phono Stage 78 dB below 10 mv input
• Line Stage 92 dB below 2.5 volt output
• Phase: Line Stage is phase inverting, Phono Stage is phase correct

Mechanical:

• 19″ X 3.15″ x 12.5″

Owner’s Manual

download

The PV14L was a remote-controlled zero-feedback vacuum-tube line-stage preamplifier with seven inputs that was designed to serve as the control center for high-performance audio and audio/video systems.

The PV14L featured a level control derived from technology developed for our Premier products. It employed a microprocessor controlled stepped attenuator with discrete resistors, which offers considerable sonic advantages over the motorized carbon track potentiometers more commonly used. This arrangement also allowed the PV14L to produce precisely repeatable volume settings.

The PV14L included a Theater input/output loop much the same as was introduced in the Premier16, which provides a locked unity gain setting, made it the ideal component to integrate home theater into their stereos without compromising the performance of their primary music system.

The PV14L incorporated an all-new zero-feedback circuit based on a single stage triode amplifier using a 6C4 miniature vacuum tube. A direct coupled buffer stage provided a low output impedance.

Replacement Tube Set RT14

V1 & V2: 8080 (6C4)

Specifications:

• Gain: 22 dB
• Maximum Output: 10.0 vrms
• Distortion: less than .25% THD or IMD
• Frequency Response: 2 Hz to 100 KHz +0/-1 dB
• Hum and Noise: 98 dB below 2.5 V
• Line Stage 92 dB below 2.5 volt output
• Phase: phase inverting

Mechanical:

• Dimensions: 14.375″D x 19″W x 3.315″H
• Weight: 14 lbs.

Owner’s Manual

download

The PV15 is a remote-controlled vacuum-tube preamplifier designed to serve as the control center for high-performance audio and audio/video systems.

The PV15 features a sophisticated level control circuit designed to allow precisely repeatable level and balance settings. With seven inputs, the PV15 will accommodate elaborate audio systems. The PV15 includes a Theater Loop which provides a locked unity gain setting, making it the ideal component for listeners who’ve been wanting to integrate home theater into their stereos without compromising the performance of their primary music system.

The PV15 zero-feedback line-stage circuit consists of a single-ended triode amplifier using a 6C4 miniature vacuum tube. A direct coupled buffer stage provides a low output impedance to insure that the PV15 can comfortably drive virtually any combination of interconnect cable and power amplifier. This circuit’s simplicity pays dividends in tonal integrity and seductive musicality while offering flexibility in system matching.

The PV15 is optionally available with a built-in phono equalization preamplifier stage to provide the additional gain and RIAA equalization that phono cartridges require.

The phono circuit uses two triode amplifier stages for voltage gain. A passive network of precision components accurately provides the required frequency compensation. A direct coupled buffer stage isolates the stage from external cables and components connected to the EPL and theater outputs. The circuit employs no negative feedback loop, eliminating feedback induced timing errors that compromise dynamics and imaging. The resulting circuit is a simple, low-noise, high-gain device well suited for use with a wide range of phono cartridges of both moving magnet and moving coil types.

Specifications:

• Gain: 28.5 dB
• Maximum Output: 5.5 vrms
• Distortion: less than 1% THD
• Frequency Response: 2 Hz to 100 KHz
• Hum and Noise: 95 dB below 2.5 V
• Phase: phase inverting
• Tube complement: 2 x 6C4 / 8080

Mechanical:

• Dimensions: 13.75″D x 19″W x 3.315″H
• Weight: 15 lbs.

Owner’s Manual

PV15
PV15ph

With the 1996 introduction of the Anniversary Reference Triode (ART), conrad-johnson established a benchmark for line-stage preamplifier performance that reigned supreme for most of a decade. Reviewers were unanimous in their praise, proclaiming it the finest sounding preamplifier ever manufactured. In 2004, the ACT2 line stage brought new materials technology and refined power supply design to the composite triode circuit pioneered by the ART, once again elevating the state of the art.

As has been our tradition at conrad-johnson, these technological advances are now offered in a more cost effective near state of the art design, the CT5 composite triode preamplifier.

The composite triode circuit is a conceptually simple design—based on creating a single “super” triode by paralleling sections of individual tubes. In this way, the entire amplification circuit can be reduced to a single active stage, without buffers or feedback. Any active circuit element will color the sound, whether the element is an amplifier or a buffer stage. By designing a line stage consisting of a single composite triode, we are able to reduce the circuit to the absolute minimum of a single active element. The result is an astonishing improvement in dynamics and dynamic shadings, as well as focus.

In the CT5, the composite triode is comprised of two paralleled sections of ultra-high transconductance miniature twin-triode tubes.

This circuit achieves a sufficiently low output impedance to drive most interconnect/amplifier combinations while eliminating any circuit element that might compromise its sonic purity. To realize the full potential of this amplifier stage, it is powered by a sophisticated discrete voltage regulator designed to completely isolate the audio signal from the power line.

All control functions of the CT5 operate through microprocessor-controlled relays.

For the level control, the relays select combinations from a network of precision, low-noise metal foil resistors to effect loudness and balance changes in 100 steps of approximately .7dB per step. All switching and adjustment can be controlled by the unit’s remote control. A Theater mode, which passes the input signal through at unity gain, makes it simple to incorporate the CT5 into a high quality home theater system without compromising its two-channel performance.

Like its bigger brother, the ACT2, the CT5 is constructed from the highest quality, carefully selected parts for unrivaled sonic performance and reliability.

The same CJD Teflon capacitors that distinguish the ACT2 are used in the CT5 for output coupling and post-regulator power supply storage. All other capacitors in the audio circuits and related power supplies are polypropylene or polystyrene, and the resistors in these circuits (including the level control) are special low inductance, high-precision laser-trimmed metal foil resistors. Switches are sealed relays with gold-plated silver contacts. Input and output connectors are premium quality custom machined parts.

In our quest to recreate the glory of music without compromise, we at conrad-johnson are dedicated to bridging the gulf between craft and art to create audio amplification components that do credit to music performances.

Through meticulous engineering, careful specification of only the finest available component parts, and a painstaking attention to construction, we have created what we feel is a line-stage without rival in its class. We invite you to arrange an audition of the CT5 with your conrad-johnson dealer to experience the extraordinary musical performance of this remarkable preamplifier.

Specifications:

• Gain: 20 dB
• Maximum Output: 10 vrms
• Output Impedance: 800 Ohms
• Distortion: less than .1% THD at 1.0 Vrms output
• Frequency response: 2 Hz to more than 10OKhz
• Hum and Noise: 100 dB below 2.5 V
• Phase:phase inverting
• Tube complement: 2 x 6N30P

Mechanical:

• Dimensions: 15.5D x 19W x 5H inches
• Weight: 31 lbs.

Owner’s Manual

download

Introduced in the internationally acclaimed Anniversary Reference Triode (ART) preamplifier, and recently refined in our current flagship preamplifier, the ACT2, conrad-johnson’s composite triode circuit has provided the benchmark for line-stage preamplifier performance for nearly a decade. Reviewers, other audio professionals, and consumers alike have been impressed by the fine resolution of subtle shadings of dynamics and the solid, stable imaging that this circuit is capable of portraying.

We are pleased to announce our most affordable implementation of this circuit in the CT6 line-stage preamplifier.

The composite triode circuit is a conceptually simple design—based on creating a single “super” triode by paralleling sections of individual tubes.

In this way, the entire amplification circuit can be reduced to a single active stage, without buffers or feedback. Any active circuit element will color the sound, whether the element is an amplifier or a buffer stage. By designing a line stage consisting of a single composite triode, we are able to reduce the circuit to the absolute minimum of a single active element.

In the CT6, the composite triode is comprised of four paralleled sections of high-transconductance miniature twin-triode tubes.

This circuit achieves a sufficiently low output impedance to drive most interconnect/amplifier combinations while eliminating any circuit element that might compromise its sonic purity. To realize the full potential of this amplifier stage, it is powered by a sophisticated discrete voltage regulator designed to completely isolate the audio signal from the power line.

All control functions of the CT6 operate through microprocessor-controlled relays.

For the level control, the relays select combinations from a network of precision, low-noise metal foil resistors to effect loudness and balance changes in 100 steps of approximately .7dB per step. All switching and adjustment can be controlled by the unit’s remote control. A Theater Mode, which passes the input signal through at unity gain, makes it simple to incorporate the CT6 into a high quality home theater system without compromising its two-channel performance.

High quality component parts specified for the CT6 have been carefully selected for unrivaled sonic performance and reliability.

All capacitors in the audio circuits and related power supplies are polypropylene or polystyrene, and the resistors in these circuits (including the CT6’s level control) are special low inductance, high-precision laser-trimmed metal foil resistors. Switches are sealed relays with gold-plated silver contacts. Even the custom machined input and output connectors have been selected for their sonic excellence.

Through meticulous engineering, careful selection of component parts, and painstaking attention to construction detail, we have created in the CT6 a true reference quality preamplifier at an attractive price. We invite you to arrange an audition with your conrad-johnson dealer to experience for yourself the extraordinary musical accuracy of the conrad-johnson composite triode preamplifiers.

Specifications:

• Gain: 26 dB
• Maximum Output: 15 vrms
• Output Impedance: 850 Ohms
• Distortion: less than .1% THD at 1.0 Vrms output
• Frequency response: at unity gain: 2 Hz to 10OKhz
• Hum and Noise: 100 dB below 2.5 V
• Phase:phase inverting
• Tube complement: 4 x 6922

Mechanical:

• Dimensions: 15.5D x 19W x 3.315H inches
• Weight: 19 lbs.

Owner’s Manual

download

The ET2 is a remote-controlled vacuum-tube preamplifier designed to serve as the control center for high-performance audio and audio/video systems.

The ET2 features a sophisticated level control circuit designed to allow precisely repeatable level and balance settings with adjustments made in .5db increments. With seven inputs, the ET2 will accommodate elaborate audio systems. The ET2 includes a Theater Loop which provides a locked unity gain setting, making it the ideal component for listeners who’ve been wanting to integrate home theater into their stereos without compromising the performance of their primary music system.

The ET2 zero-feedback line-stage circuit consists of a single-ended triode amplifier using a high current vacuum tube.

A direct coupled buffer stage provides a low output impedance to insure that the ET2 can comfortably drive virtually any combination of interconnect cable and power amplifier. This circuit’s simplicity pays dividends in tonal integrity and seductive musicality while offering flexibility in system matching.

The ET2 is optionally available with a choice of two built-in phono equalization preamplifier stages (a high gain stage and a low gain stage) to provide the additional gain and RIAA equalization that phono cartridges require.

The phono circuit uses two triode amplifier stages for voltage gain. A passive network of precision components accurately provides the required frequency compensation. A direct coupled buffer stage isolates the stage from external cables and components connected to the EPL and theater outputs. The circuit employs no negative feedback loop, eliminating feedback induced timing errors that compromise dynamics and imaging. The high gain phono stage is suited for use with low to medium output moving coil cartridges with rated output of 1.0 mV or less. The low gain stage is recommended for cartridges with output above 1.0 mV.

Specifications:

ET2 line stage

• Gain: 28.5 dB
• Maximum Output: 5.5 vrms
• Distortion: less than .1% THD
• Freq. Response: 2 Hz to 100 KHz +0/-1 dB
• Hum and Noise: 95 dB below 2.5 V
• Phase: phase inverting

ET2 Optional High Gain Phono Stage

• Gain: 54dB
• RIAA Equalization: +/- .5 db 20 Hz to 20 kHz
• Phase: phase correct

ET2 Optional Low Gain Phono Stage

• Gain: 40dB
• RIAA Equalization: +/- .5 db 20 Hz to 20 kHz
• Phase: phase correct

Mechanical:

• Dimensions: 13.75D x 19W x 3.315H inches
• Weight: 15 lbs.

Owner’s Manual

download

The HV-1 Pre-Preamplifier was the first active phono pre-preamplifier from conrad-johnson.

It was a simple linear gain stage designed to provide the added gain required by low output moving coil cartridge. The HV-1 used the latest in vacuum tube technology, the nuvistor. Nuvistors are small metal-enclosed triode vacuum tubes noted for their extraordinary linearity and low noise.

RF Filters and traps were judiciously executed to minimize noise and external interference, two things that made many other pre-preamps unacceptable in audiophile systems. Twin cascaded voltage regulators rejected AC line fluctuations and a separate regulator for the filament supply ensured large dynamic range and excellent frequency response.

The HV-1a update included upgraded coupling capacitors and an improved power supply regulator. The result was greater depth and spatial detailing.

HV1 & HV1a- V1 – V2: 6CW4 Replacement Tube Set RTHV1

Specifications:

• Input Impedance 100 ohms (phono overload 200 mV at 1kHz)
• Gain: 28 dB
• Maximum Output: 5.5 vrms
• Distortion: less than .05% THD or IMD
• Response: bandpass 20Hz to more than 20kHz
• Tube Complement: 2 X 6CW4

Mechanical:

• Dimensions: 19″ X 3″ x 10 1/8″
• Weight: 6 lbs.

The HV-2 was an active vacuum-tube phono pre-preamplifier.

It was a simple linear gain stage designed to provide the added gain required by low output moving coil cartridge. Based on the previous model HV-1, the HV2 also used nuvistors – small metal-enclosed triode vacuum tubes noted for their extraordinary linearity and low noise.

These phono pre-preamplifiers featured carefully executed RF Filters and traps to minimize noise and external interference, avoiding the pitfalls common to many other active pre-preamplifiers.

The HV2 fitted the proven HV1a circuitry into a more economical package at a reduced price.

V1 & V2: 6CW4 Replacement Tube Set RTHV1

Specifications:

• Input Impedance 100 ohms (phono overload 200 mV at 1kHz)
• Gain: 28 dB
• Maximum Output: 5.5 vrms
• Distortion: less than .05% THD or IMD
• Response: bandpass 20Hz to more than 20kHz
• Tube Complement: 2 X 6CW4

Mechanical:

• Dimensions: 19″ X 3″ x 10 1/8″
• Weight: 6 lbs.

The EV1 was a separate phono equalization preamplifier designed to provide the additional gain and RIAA equalization that modern phono cartridges require.

Based on the circuit used in conrad-johnson’s acclaimed Premier Fifteen, the EV1 used a single-ended triode input amplifier comprised of both sections of a miniature twin–triode tube connected in parallel for reduced noise. A second single-ended triode amplifier provided added gain. A passive network of precision components between these two stages set the required frequency equalization. A direct coupled cathode follower output stage yielded a low output impedance.

The EV1’s circuit employs no negative feedback loop. The EV1 was a simple, low-noise, high-gain device well suited for use with a wide range of phono cartridges of both moving magnet and moving coil types.

V1 & V2: 12AX7 | V3: 5751 | V4: 12AU7

Specifications:

• Gain: 49 dB
• Phono Overload: 200 mV
• Distortion: less than .05% THD or IMD
• Phono Equalization: within +/- .25 dB of RIAA
• Hum and Noise: 78 dB below 10mV input
• Phase: phase correct

Mechanical:

• Dimensions: 14.375D x 19W x 3.315H inches
• Weight: 14.5 lbs.

The TEA1 triode equalization amplifier is a phono stage available in four different versions to meet a wide range of needs – all designed to satisfy the expectations of the most demanding music lovers.

All versions share a common circuit approach featuring a zero loop feedback circuit with passive RIAA equalization. All feature two phono inputs, one with switch selectable resistive and capacitive loading allowing the user to fine-tune performance to the chosen phono cartridge. With the exception of capacitors in the audio circuits and related power supplies, parts quality is identical in all four versions. All resistors are top quality precision metal foil types. I/O connectors are custom made gold-plated machined oxygen-free copper.

The TEA1b is the base model TEA1.

In the TEA1b, the two phono inputs each provide 54.5 db of gain. Resistive and capacitive loading can be adjusted by toggle switches on the PHONO 2 / Variable Load input. The base model uses CJD Teflon capacitors for all but the highest value capacitors (2.0 micro Farad and higher) in the audio circuit which are polypropylene bypassed by Teflon.

A capacitor upgrade is incorporated in the otherwise identical TEA1bc, replacing a number of high value polypropylene capacitors with multiple 2.0 micro Farad CJD Teflon capacitors.

The TEA1bt upgrades the base model by adding premium wide-bandwidth audio transformers to the PHONO 1 input to provide the higher gain and very low noise required by low output moving coil cartridges. The active circuit is modified to reduce its gain to 45 db, offering the user one HIGH GAIN transformer coupled input (PHONO 1) with 63 db of gain and one LOW GAIN direct input (PHONO 2) with 45 db of gain.

The fully configured TEA1 includes both the transformer option and the capacitor upgrade.

Designed to precisely track the prescribed RIAA equalization curve, the TEA-1 assures absolute tonal accuracy.

The low-gain audio circuit of the TEA-1 is comprised of two cascaded single-ended triode amplifiers. The circuit is a zero-feedback design, to eliminate the temporal inaccuracies that negative feedback introduces. RIAA equalization is established by a passive network between the two gain stages. Careful implementation of this fundamentally simple circuit results in extremely wide bandwidth, and low distortion, without resorting to negative feedback. Precision wound input transformers provide the additional 18 dB of gain for the high-gain inputs.

The ideal dc power supply circuit is simply a zero impedance path to ground.

Any deviation from this ideal is fully reflected in the audio circuits. Thus the power supplies are as important to audio performance as the audio circuits and must be accorded equal attention in design. In the TEA-1, each stage has its own discrete regulated DC power supply. These power supplies have been carefully designed for minimum impedance, even at the highest audio frequencies, to prevent the power supplies from degrading music reproduction.

The full potential of any circuit design can only be realized if executed with the highest quality parts.

The audio circuits of the TEA-1 use only conrad-johnson’s proprietary Teflon capacitors. In the power supplies, all capacitors are polypropylene and Teflon composites—there are no electrolytic capacitors anywhere in the audio circuits or their dc power supplies. The audio circuits and related power supplies both use high-precision laser trimmed metal-foil resistors, designed for ultra-low inductance. All parts in the TEA-1’s RIAA compensation network are 1% tolerance, to assure precise tracking of the RIAA curve. Input and output connectors are gold-plated, machined oxygen free copper. Even the hookup wiring has been carefully selected for optimal audio performance.

Thoughtful engineering, specification of the finest available component parts, and painstaking care taken in production make the TEA-1 a phono equalization preamplifier without peer in music reproduction. We invite you to arrange an audition with your conrad-johnson dealer to confirm for yourself the extraordinary musical performance of these products.

Specifications:

• Gain (TEA1 and TEA1bt): Low Gain Input – 45 dB | High Gain Input – 63 dB
• Gain (TEA1b and TEA1bc): Both Inputs – 54.5 dB
• Overload (TEA1 and TEA1bt): Low Gain – 110 mV | High Gain – 12 mV
• Overload (TEA1b and TEA1bc): Both Inputs – 50 mV
• Hum and Noise: Direct Inputs – 82 dB below 10 mV input
• High Gain (TEA1 and TEA1bt) only – 80 dB below 1 mV input
• Phase: phase correct
• Ouput Impedance: below 200 ohms

Mechanical:

• Dimensions: 15.5″D x 19″W x 3.315″H
• Weight: 23 lbs.

Owner’s Manual

TEA1
TEA1b

The MET1 is designed to satisfy those who are seeking a great sounding multi-channel theater and music system.

One that can bring home the joy of live music performances as well as the thrill of the movie theater. A system that can fully reveal the higher resolution of new digital formats. A system that sounds at least as good on stereo records and CDs as their two channel system did. And a system that works in a familiar, intuitive way.

Conrad-Johnson’s MET1 is part of our distinctively different approach to multi-channel audio.

It is a 6-channel vacuum-tube analog preamplifier, intended to be used in conjunction with a high-end disc player with built-in digital decoding. It is the key element in assembling a component multi-channel system designed to the high standards that you’ve come to expect from an audiophile stereo system. There are several advantages to using the MET1 as the control center for your surround sound system.

What advantages does the MET1 offer?

Using a 6-channel preamplifier is the only way to enjoy the benefits of the high resolution SACD and DVDA formats. SACD players do not output a digital signal when the SACD layer is played, and DVDA players typically output only a down-sampled (CD quality) digital signal. Only the internal DACs of these players have acess to the high-resolution data, which is decoded to provide a full information analog output signal. Unlike surround-sound processors, the MET1 is an audiophile quality preamplifier capable of passing along this analog signal with no redundant digital conversions, no additional digital processing, and no substandard analog circuits. The listener is able to fully appreciate the remarkable musicality that these high-resolution formats offer.

With the MET1, there is no need to have separate systems for music and cinema.

It seamlessly integrates your home theater with your music system without compromising the musical performance of the system. It is a true, audiophile class line-stage preamplifier, capable of high-end two channel performance as well as state of the art multi-channel playback.

The sonic refinements that are critical to high-end music playback are equally important to cinema playback.

The MET1 will convey to you the subtle inflections and shading of voice that the best actors use to convey emotion in their performances. We believe you will achieve a higher appreciation of the actors performance, just as you can with a musicians performance.

The MET1 features two sets of 6-channel inputs and three pairs of stereo inputs.

With stereo inputs, an Ambience Retrieval Mode (ARM) can be enabled to extract six channels of information from the stereo source – a synthesized surround sound that is remarkably effective on live recordings, as well as early quadrophonic recordings.

The user interface for the MET1 has been designed for convenient and intuitive operation. An easily accessible setup mode allows quick adjustment of the relative levels of the six channels. All front panel controls are duplicated on the full-function remote.

As is expected from conrad-johnson, the MET1 is constructed exclusively of premium quality parts, carefully selected for unrivaled sonic performance and reliability.

The audio circuits and related power supplies employ polypropylene and polystyrene capacitors and precision low inductance laser-trimmed metal foil resistors exclusively. The obsession for parts quality extends to the high quality, gold plated input and output connectors.

If you are ready to take the audiophile’s approach to surround music and theater, we invite you to visit your conrad-johnson dealer to discover for yourself just how simple and musically satisfying surround sound can be.

Specifications:

• Gain: 25.5 dB
• Maximum Output: 6 vrms
• Distortion: less than .1% THD at 1.0V output
• Bandwidth: 2 Hz to 100 KHz
• Hum and Noise: 100 dB below 2.5 V
• Output Impedance: 200 Ohms
• Tube complement: 6 x M8080/6C4

Mechanical:

• Dimensions: 15.5D x 19W x 5H inches
• Weight: 27 lbs.

Owner’s Manual

download

The PF1 was the first solid state preamp bearing the
conrad-johnson name.

More than one decade of research and development led to the introduction of PF1. The circuit design featured a unique distortion canceling circuit that resulted in excellent linearity without resorting to global negative feedback. Independent discrete dc power supply regulators were used for each gain stage for absolute insolation between stages.

Parts quality was to conrad-johnson’s usual high standards. All capacitors, including power supply, were polypropylene and cjd polystyrene. There were no electrolytic capacitors in the PF1. All resistors were 1% metal-oxide deposited on glass construction resulting in very low noise. The PF1 nicely combined the lucidity and harmonic balance of c-j vacuum tube preamps with the superb definition and detail of transistor designs.

The PF1L is a line-stage only (no phono preamp) version of the PF1.

Features:

Inputs/Outputs

• phono
• tuner
• auxiliary
• monitor and recording facilities for two tape decks with dubbing from Tape 1 to Tape 2
• Two power amplifier (main) outputs

Controls:

• selector
• tape 1/source/tape 2
• mode (left/right/stereo/rev/mono)
• balance
• volume

Specifications:

• Gain: Phono Stage 40 dB (phono overload 100 mV at 1kHz)
• Line Stage 21 dB
• Distortion: less than .1% THD or IMD
• Response: bandpass 2Hz to more than 75kHz
• RIAA Equalization: +/- .25 dB (20 to 20 kHz)
• S/N Ratio: Phono Stage 80 dB below 10 mv input
• Line Stage 94 dB below 2.5 volt output
• Phase: Phono Stage is phase correct, Line Stage is phase inverting

Mechanical:

• 19 x 3″ x 12″

Owner’s Manual

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The PF2 superseded the PF1.

The line stage circuits were virtually identical. The PF2 offered an improved phono circuit, with selectable gain settings (40,46, and 52 dB). This made the PF2 better suited for use with low output moving coil cartridges.

The PF2 maintained the exceptional parts quality standards of the PF1. Capacitors were polypropylene and cjd polystyrene including the power supply filter caps. All resistors were 1% metal-oxide deposited on glass construction. Input/output connectors were upgraded from those found in the PF1.

Noted for the lucidity and harmonic balance of the cj vacuum-tube preamps, the PF2 refined the achievements of the PF-1 with the superb definition and detail of transistor designs.

Features:

Inputs/Outputs

• Aux/Phono
• Tuner
• CD
• Tape 1
• Tape 2
• Rec 1 and Rec 2 outputs
• Main outputs.

Controls:

• Source
• Record (selects source for the Record outputs)
• Balance
• Volume

Specifications:

• Gain: Phono Stage 40, 46, or 52 dB selectable (phono overload 65 mV at 1kHz)
• Line Stage 20 dB
• Distortion: less than .1% THD or IMD
• Response: bandpass 2Hz to more than 100kHz
• RIAA equalization +/- .25 dB (20 to 20 kHz)
• S/N Ratio: Phono Stage 86 dB below 10 mv input
• Line Stage 94 dB below 2.5 volt output

Mechanical:

• 19″ x 3.315″ x 14 3/8″

Owner’s Manual

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The PFR consisted of conrad-johnson’s unique autolinear gain circuit executed to Premier parts standards.

The inclusion of a full-featured remote control made this an unrivaled pairing of sonic excellence and convenience.

The bill of materials included exclusive use of 1% tolerance metal film resistors, and the use of high-value polystyrene capacitors for all circuit applications except power supply input filters. Premium quality machined input/output connectors were specified for the PFR. This was truly a Premier product in all but name.

The PF1L is a line-stage only (no phono preamp) version of the PF1.

Features:

Inputs/Outputs

• Aux 1/Phono
• Tuner
• CD
• Aux 2
• EPL 1 Input and Output
• EPL 2 Input and Output
• Main outputs.

Controls:

• 5 Sources
• EPL 1
• EPL2
• Balance
• Mute
• Volume

Specifications:

• Gain: 20 dB
• Distortion: less than .1% THD or IMD
• Response: bandpass 2Hz to more than 100kHz
• Response: bandpass 2Hz to more than 100kHz
• S/N Ratio: Line Stage 94 dB below 2.5 volt output

Mechanical:

• 19″ x 3.315″ x 14 3/8″
• Weight: 17.5 lbs.

Owner’s Manual

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The EF1 is a highly refined phono preamplifier designed to faithfully reproduce live musical performances, and to maintain their sonic excellence over the years.

The EF1 is a separate phono equalization preamplifier, designed to provide the added gain and RIAA equalization required by modern phono cartridges.

The EF1 features low noise circuitry and selectable gain (40, 46, and 52 dB) to accommodate the full range of phono cartridges from low output moving coil to high output moving magnet types. A buffered output stage results in a low output impedance for the EF1.

First and foremost, the EF1 is an instruments for the reproduction of recorded music. The primary design objective was to create circuits which were capable of recreating the emotional impact of experiencing live music. A number of critically important considerations entered into the design process.

Field Effect Transistors (FETs)

More important than the total amount of distortion of an audio circuit is the character of the distortion. Odd-order harmonic distortion products are amusical, whereas even-order distortion products are part of the natural overtones. FETs have been selected for the active devices in the EF1 because, like tubes, and unlike bi-polar transistors, they produce almost no odd-order harmonic distortion.

Minimal Negative Feedback

Negative feedback is an engineering technique used to reduce measured distortion. While feedback does achieve this goal, it also introduces aberrations in the transient response characteristics of the circuit. The EF1 uses conrad-johnson’s unique auto-linear gain block which achieves low distortion with zero loop feedback by exploiting the symmetrical distortion properties of n and p channel fets.

Quality Parts

The EF1 conform to the unmatched standard of parts quality for which conrad-johnson’s Premier products are internationally known. Capacitors are polystyrene or polypropylene “by-passed” by polystyrene, including all power supply create circuits which were capable of recreating the emotional impact of experiencing live music. A number of critically important considerations entered into the design process.

Low Dynamic Impedance Power Supplies

DC power supplies are an inseparable part of the audio signal path, and require as much care in design as the audio circuits. An ideal power supply would have zero ac impedance, so that the power supply voltage could not fluctuate with the audio signal. conrad-johnson products feature discrete dc regulated power supplies designed for vanishingly low impedance even at high audio frequencies. For the EF1, a primary line regulator filters and stabilizes the input voltage, isolating all circuits from power line fluctuations and noise. This regulated supply in turn delivers stabilized dc current to two separate secondary regulators for each gain stage. These regulators employ discrete devices and the highest quality polypropylene and polystyrene capacitors in circuits designed to provide a low impedance at all audio frequencies, for an extremely stable source of dc current.

Specifications:

• Gain: 40, 46, 52 dB (selectable)
• Phono Overload: 70 mV (40 dB gain setting)
• Phono Equalization: within +/- .25 dB of RIAA
• Hum and Noise: 88 dB below lOmV input
• Phase: phase correct

Mechanical:

• Dimensions: 14.375D x 19W x 3.315H inches
• Total weight: 14.5 lbs.

Owner’s Manual

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The conrad-johnson Enhanced Triode (ET) Amplifiers are power amplifiers designed to capture the best attributes of both fine vacuum-tube designs and of the best solid-state designs.

The ET250S is a 250-watt per channel stereo power amplifier, the MET150 a five-channel amplifier rated at 150 watts per channel.

These sophisticated zero-feedback amplifiers offer the refinement of a vacuum-tube amplifier with the guts and control of a solid-state amplifier.

Zero Feedback.

Negative feedback is an engineering technique used to reduce measured distortion. While feedback does achieve this goal, it also introduces aberrations in the tran­sient response characteristics of the circuit. We have found that eliminating loop negative feedback can result in much finer gradations in dynamic response (micro-dynamics) and more accurate decay on musical transients. But eliminating negative feedback requires much more care in the design of the circuits—both in choosing devices and in power-supply design—and places greater demands on the parts.

The Right Device for the Job.

A power amplifier has two distinctly different functions. First, a voltage gain stage must increase the amplitude of the input signal by a factor of about thirty. The distortion characteristics of the amplifier are dominated by this stage. No device is better suited to accurately amplifying signals at high amplitude than triode vacuum tubes. For our enhanced triode amplifiers, voltage gain is provided by a 6922 vacuum tube, selected for its ability to track a high amplitude signal accurately. Theory and 30 years of experience have taught us that the voltage gain stage of a power amplifier dominates the sonic character of the critical mid-range of a power amplifier, and indeed these amplifiers exhibit the smooth, lucid midrange for which tube amplifiers are so highly esteemed.

The high amplitude signal produced by the voltage gain stage must then be efficiently coupled to the loudspeaker system through an output stage to produce the power and control needed for a musically accurate response – basically to provide current gain and a low output impedance. High-current bi-polar devices have been specified for the output stages of these amplifiers, based on their extremely low output impedance and their ability to handle a great deal of current. This contributes the fast, weighty bass and seemingly limitless power reserve that are notable in these amplifiers.

Solid Power Supplies.

Rock solid power supplies are needed to enable the audio circuits to reach their potential on musical transients. The ET amplifiers feature oversized main power transformers (so that the circuits are not starved for current), and massive power storage reservoirs with high-speed capacitor shunts to deliver quick, even startling transient response. Carefully designed DC voltage regulators isolate the critical voltage gain stages to prevent demands of the output stage from modulating the input signal.

Quality Parts.

Conrad-Johnson components are internationally known for the quality of their parts, and the ET amplifiers are no exception. The audio circuits and their related power supplies utilize precision low inductance laser-trimmed metal foil resistors. The circuits employ polypropylene, polystyrene and Teflon capacitors extensively, except in the main power supply storage, where high-speed electrolytics are used because of the extremely high capacitance required. Precision-machined input/output connectors have been carefully selected for optimal sonic performance. Even the internal wiring is chosen on the basis of its sound quality in its specific application.

Thoughtful engineering, specification of top quality component parts, and painstaking care taken in production make the MET150 and ET250S capable of extraordinary performance in music reproduction.

We invite you to arrange an audition with your conrad-johnson dealer to confirm for yourself the extraordinary musicality of these amplifiers.

Specifications

Power:

ET250S – 250 Watts per channel from 20 Hz to 20 KHz at no more than 2 % THD, both channels driven into 8 Ohms, or 400 watts per channel driven into 4 Ohms.

MET150 – 5 x 150 Watts from 20 Hz to 20 kHz at no more than 2 % THD into 8 Ohms, or 5 x 250 Watts into 4 Ohms.

Sensitivity:

ET250S – 1.85V to rated power.
MET150 – 1.5V to rated power.

Frequency Response (at 10 Watts): 20 Hz to 20 kHz, +/- .25 dB
Hum and Noise: 104 dB below rated power
Input Impedance: 100 kOhms

Tube Complement:

ET250S – 2 x 6922
MET150 – 5 x 6922

Mechanical:

Dimensions (ET250S and MET150) – 16.125D x 19W x 7.188H inches
Weight (ET250S and MET150) – 65 Lbs.

Owner’s Manual

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The Evolution 20 was the only preamp made by conrad-johnson to bear the Evolution Series name.

The Evolution Series were products of a unique nature that fit between the standard conrad-johnson product line and the exclusive Premier product line.

The EV20 was actually two mono preamplifiers with separate power supplies combined into a single stereo package sharing only the chassis, ac line cord, and power transformer. Coupling between channels is thereby held to a minimum. The circuit was an end-to-end zero feedback design derived directly from that of the flagship Premier Seven preamplifier, with minor compromises needed to fit it all into a single chassis (in contrast to the Premier Seven’s four).

Built like a battleship, the EV20’s superior external construction and quality feel of controls are immediately apparent. The famous “cjd” capacitors and high-precision laser trimmed metal-foil resistors are used throughout. The volume control is a 23-position switch selecting among 23 pairs of resistors ­ never more than a single-pair of resistors are inserted in the signal path by this control. The balance control is an 11 position switch that is electrically out of the circuit in the centered position.

The EV20 had outstanding dynamic range and extended low bass along with the depth and spatial characteristics for which conrad-johnson is noted, making the EV20 one of the finest preamps available at the time.

V1, V2: 6CW4 | V3, ­V10: 6GK5

Features:

Inputs / Outputs

• one phono
• tuner
• auxiliary
• CD
• monitor and recording facilities for two tape decks with dubbing from Tape 1 to Tape 2
• one pair power amplifier (RCA main) outputs

Controls

• selector
• record
• balance
• volume
• power

Specifications:

• Gain: 40 dB Phono Stage
• Line Stage 25 dB
• Distortion: less than .5% THD or IMD at 1.0 V output
• Response: bandpass 2Hz to more than 100kHz
• RIAA Equalization +/- 0.25 dB (20Hz to 20KHz)
• S/N Ratio: Phono Inputs 80 dB below 10 mV input
• Line Stage 94 dB below 2.5 volt output
• Phase: Line Stage – phase inverting | Phono Stage ­phase correct

Mechanical:

• Dimensions: 15D x 19W x 7H inches
• Total weight: 37 lbs.

Owner’s Manual

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The Evolution 2000 was a genuinely unique design drawing on the many year’s experience conrad-johnson had with both vacuum tube and solid-state circuits.

The EV2000 uses MOSFETs for output devices and vacuum tubes for the input stage making the EV2000 a truly hybrid design.

It was a straightforward response to the challenge of producing a true zero-feedback power amplifier. Since only square-law valves are deployed in the EV2000, only second order distortion products are produced. Odd order distortion components, which are most noticeable and objectionable to the human ear, are virtually non-existent. Triode vacuum tubes were selected to provide all of the voltage gain. Current gain is provided by two stages of complimentary MOSFET source followers, the final stage consisting of five-pairs of high current devices for a nearly unlimited capacity to deliver current into reactive loudspeaker loads. High current delivery was facilitated by a massive, oversized, dedicated power transformer (nearly 50 lbs.) used for the solid state output devices. The MOSFET output stage eliminated the bandwidth limitations and phase shift associated with output transformers, and at the same time achieved a much lower output impedance than would be possible with a vacuum tube output stage.

The EV2000 offered the tonal integrity of the finest vacuum tube amplifiers combined with the speed and detail of superior transistor designs. Individual voices and instruments are faithfully reproduced and remain tightly focused on the soundstage no matter how complex the musical passage.

V1,­ V4: 5751

Features:

Inputs / Outputs

• power switch
• left and right RCA input jacks
• left and right output jacks (5 way binding posts)

Specifications:

• Power Output – 200 watts per channel from 20Hz to 20KHz with no more than 1% THD or IMD, both channels driven into 8 ohms.
• Input Sensitivity: 900mV to full power
• Response: 20Hz to more than 20kHz , +0, -.5dB
• S/N Ratio: 96 dB relative to max output

Mechanical:

• Dimensions: 22D x 19W x 10H inches
• Total weight: 114 lbs.

Owner’s Manual

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MV45, MV45A, MV45A-1 Vacuum Tube Power Amplifiers

The MV45 vacuum tube power amplifier was designed for audiophiles who had moderately efficient speaker systems and for less efficient speakers systems if high listening levels were not required. A single pair of EL34 output tubes produced 45 watts per channel. The MV45 employed metal film resistors and polyester and silvered mica capacitors throughout the circuitry.

The MV45A revision upgraded the mylar capacitors to polypropylene capacitors. The MV45A-1 upgrade incorporated circuit revisions to reduce the impedance of the regulated power supplies for the voltage amplifier and inverter stages.

Features:

• 4, 8, 16 ohm speaker taps (screw type)
• one pair of inputs
• power switch
• optional rack mount panel

Replacement Tube Set RT45

V1: 5751 | V2 & V3: 12AT7 | V4-V7: 6CA7/EL34

Specifications:

• Power: 45 watts per channel, RMS, at 4, 8, or16 ohms with both channels driven from 30Hz to 15kHz with no more than 1% THD or IM Distortion
• Response: 20Hz to 20 kHz, +0, -.5 dB
• Input Sensitivity: 0.80 volts
• Hum & Noise: 90 dB below 75 watts

Mechanical:

• Dimensions: 14W | 6H | 9D inches
• Weight: 33 lbs.

Owner’s Manual

MV45
MV45a

MV50 Vacuum Tube Power Amplifier

The MV50 was, in effect, a more refined version of the earlier MV45. The input voltage amplifier included a cathode follower to provide low impedance drive to the inverter stage, to which it was direct coupled, eliminating one capacitor from the signal path. The remaining coupling capacitors were “cjd” polystyrene. Separate discrete dc voltage regulators supplied dc voltage to the input amplifier and the phase inverter.

Features:

• 4, 8, 16 ohm speaker taps (screw type)
• one pair of inputs
• two plate fuses
• power switch
• rack mount front panel

Replacement Tube Set RT50

V1 & V2: 5751 | V3 & V4: 6FQ7 | V5-V8: 6CA7/EL34

Specifications:

• 45 watts per channel RMS, at 4, 8, or16 ohms both channels driven from 30Hz to 15kHz with no more than 1% THD or IMD.
• Input Sensitivity: 2.35 Volts RMS to rated power
• Frequency Response: 20Hz to more than 20kHz , +0, -.5dB
• Hum & Noise: 90 dB below 45 watts

Mechanical:

• Dimensions: 19W | 9H | 11.5D inches
• Weight: 39 lbs.

Owner’s Manual

MV50

MV52 Vacuum Tube Power Amplifier

The MV52 considerably refined the circuit design of the MV50 which it superseded. In the MV52 two sections of the input tube were connected in parallel to reduce the source impedance of the voltage amplifier, eliminating the cathode follower of the MV50. Probably the most significant change introduced in the MV52 was the use of polypropylene capacitors for the main power supply filter and reservoir ­eliminating electrolytic capacitors from the main power supplies. This was the first power amplifier to offer an all polypropylene main power supply. All other circuit capacitors in the MV52 were “cjd” polystyrene.

Features:

• 4, 8, 16 ohm speaker taps (screw type)
• one pair of inputs
• two plate fuses
• power switch
• rack mount front panel

Replacement Tube Set RT52

V1 & V2: 5751 | V3 & V4: 6FQ7 | V5-V8: 6CA7/EL34

Specifications:

• 45 watts per channel RMS, at 4, 8, or16 ohms both channels driven from 30Hz to 15kHz with no more than 1% THD or IMD
• Input Sensitivity: 0.80 Volts RMS to rated power
• Frequency Response: 20Hz to more than 20kHz , +0, -.5dB
• Hum & Noise: 92 dB below 45 watts

Mechanical:

• Dimensions: 19W | 7H | 13 5/8D inches
• Weight: 40 lbs.

Owner’s Manual

MV52

MV55 Vacuum Tube Power Amplifier

The MV55 continued the evolutionary development of our entry-level MV series amplifier, offering circuit refinements to the preceding MV52. The MV55 was offered in both ultra-linear and triode configurations. Triode operation of the output stage achieves an exceptionally rich and musical sound, but at reduced power levels.

Like the MV52, the MV55 features the use of polypropylene capacitors for the main power supply filter and reservoir – eliminating electrolytic capacitors from the main power supplies.

Features:

• 4, 8, 16 ohm speaker taps (screw type)
• one pair of inputs
• two plate fuses
• power switch

Replacement Tube Set RT55

V1 & V2: 12AX7 | V3 & V4: 6SN7 | V5-V8: 6CA7/EL34

Specifications:

• Power Output ­ Ultralinear Operation: 45 watts per channel RMS at 4, 8, or16 ohms both channels driven from 30Hz to 15kHz with no more than 1% THD or IMD
• Power Output ­Triode Operation: 22 watts per channel RMS at 4, 8, or16 ohms both channels driven from 30Hz to 15kHz with no more than 1.5% THD or IMD
• Sensitivity: .55 V to rated power (ultralinear)
• Frequency Response: 20Hz to 20 kHz, +0, -.5 dB
• Input Sensitivity: 0.55 volts to rated power
• Hum & Noise: 98 dB below rated power

Mechanical:

• Dimensions: 17.5W | 7H | 12.75D inches
• Weight: 39 lbs.

Owner’s Manual

MV55

MV60 Vacuum-Tube Power Amplifier

For nearly thirty years, conrad-johnson has helped define the concept of high end audio through its relentless pursuit of excellence, its use of only the finest available component parts, and its single-minded dedication to building the best high-fidelity products available. Less frequently acknowledged, however, is conrad-johnson’s dedication to the “forgotten” audiophile – the dedicated music-lover who requires musically satisfying performance but whose budget does not aspire to the loftiest of current offerings. For as long as the company has been producing its world-renowned Premier series of audio instruments, it has also been adapting the technologies and construction techniques responsible for those products and applying them to a more affordable, but equally discriminating, line of components.

The MV60 is the latest link in that chain and it personifies the same compulsive attention to even the smallest detail that differentiate the true audio originals from less serious designs. The MV60 is a 55 watt per channel stereo vacuum-tube power amplifier that achieves its true-to-life sound through a combination of canny engineering and daring innovation.

Consistent with conrad-johnson’s design philosophy that circuits should be kept as simple as possible, the MV60 works its magic with just eight vacuum tubes.

A composite triode input stage is direct coupled to a cathode-coupled phase inverter. The two sections of the phase inverter drive the output stage, which is comprised of a pair of EL34s operated in an ultra-linear configuration, producing 55 watts per channel. Limited negative feedback is applied to the circuit to reduce distortion and provide a sufficiently high damping factor to control most real-world speaker systems. Discrete dc power supply regulators are provided for the input and inverter stages, in order to isolate each stage from the output signal.

Variations on this simple circuit have provided the blueprint for many superb sounding CJ products in the past.

This latest iteration benefits from recent advances achieved in our Premier range of products. Conrad-Johnson’s continuing research into transformer design has uncovered an intricate variation on transformer construction that results in unusually wide bandwidth output transformers. These ultra wide-band Trans-spectral transformers are used in all of the current Premier power amplifiers. The MV60 is the first time these costly transformers have been used outside the Premier range. The MV60 also benefits from recent advances in power supply design developed for conrad-johnson’s flagship products.

conrad-johnson products are internationally known for setting the standard of parts quality for the industry, and the MV60 proudly upholds that tradition.

Premium-quality parts are used throughout. All circuit capacitors, including the main power supply filter and storage capacitors, are polypropylene – there are no electrolytic capacitors in the audio circuit or in the related power supplies. All audio circuit resistors are special high-precision, low-noise metal film types. The obsession for parts quality extends to the precision machined, gold plated input jacks and output connectors ‹ even the internal wiring was chosen on the basis of its sound quality in its specific application. The MV60 was subjected to exhaustive batteries of instrumental and listening tests before its design was finalized.

The result of all this painstaking attention to detail is an amplifier that is both refined and surprisingly powerful.

Although it is conservatively rated at 55 watts per channel, it offers sufficient power to drive all but the most difficult speaker systems reliably for thousands of hours of listening pleasure without requiring complex user-adjustments. Users who have not previously experienced the dynamic range and lifelike timbre of tubed components will find the MV60 an ideal introduction to the joys of modern tubed products. Along with its tonal integrity, its ease of use, low maintenance costs, and reliability will be a revelation for those who have only experienced “entry-level” tubed gear. For veteran audiophiles, its modest price and size make it the perfect “second system” amplifier, bringing conrad-johnson quality and reliability to a different room from the state of the art primary system. A word of warning if you are in this last group: whether in the den, library, or bedroom, the MV60’s wide bandwidth and low distortion will give your main system a run for the money.

Specifications:

• Power (ultralinear operation): 55 watts per channel from 30 Hz to 15 kHz at no more than 1% THD, both channels driven into 4, 8, or 16 Ohms (when re-connected for the chosen load impedance)
• Power (triode operation): 25 watts per channel from 30 Hz to 15 kHz at no more than 1.5% THD, both channels driven into 4, 8, or 16 ohms. (when re-connected for the chosen load impedance)
• Sensitivity: .8 volts rms to rated power (ultra-linear)
• Gain: 26 dB
• Freqency Response: 20 Hz to 20 KHz +0/-.5 dB
• Hum and Noise: 95 dB below 55 watts
• Input Impedance: 100 Kohms
• Phase: phase correct

Mechanical:

• Dimensions: 17.625W | 7H | 13.25D inches
• Weight: 48 lbs.

Owner’s Manual

MV60
MV60se

conrad-johnson MV75 Vacuum Tube Power Amplifier

An immediate success, and widely acclaimed as a state-of-the-art contender, this power amplifier strongly signaled that conrad-johnson was indeed a serious company. Like the PV1, the MV75 employed metal film resistors and mylar capacitors throughout the circuitry.

The MV75 broke new ground in tube amplifier design by featuring a built in bias indicator circuit to simplify bias adjustment for the tube output stage-a task that must be performed whenever output tubes are changed, and periodically as they age. Earlier tube amplifiers required additional test equipment and technical expertise to set the bias for the output stage-a daunting task for many owners. The MV75 included a built in LED bias indicator for each output tube requiring only a screwdriver to accurately set the bias. This arrangement made it a simple matter for owners to keep their amplifiers operating at peak performance. All subsequent conrad-johnson tube amplifiers have included this built in bias indicator.

The MV75A upgrade added high-voltage fuses to protect the amplifier from shorted output tubes and upgraded the mylar capacitors to polypropylene. The MV75A-1 upgrade included circuit revisions to reduce the impedance of the regulated power supplies for the voltage amplifier and inverter stages.

Features:

• 4, 8, 16 ohm speaker taps (screw type)
• one pair of inputs
• two plate fuses (MV75A, and MV75A-1)
• mono switch
• power switch
• optional rack mount panel and tube cage

Replacement Tube Set RT75

V1: 5751 | V2 & V3: 6FQ7/6CG7 | V4-V7: 6550

Specifications:

• Stereo 75 watts per channel, RMS, at 4, 8, or16 ohms with both channels driven from 30Hz to 15kHz with no more than 1% THD or IMD. Monaural 150 watts, RMS, at 4, 8, or 16 ohms from 30 Hz to 15 kHz, with no more than 1% THD or IMD.
• Input Sensitivity: 2.35 Volts RMS to rated power
• Frequency Response: 20Hz to more than 20kHz , +0, -.5dB
• Hum & Noise: 94 dB below 75 watts

Mechanical:

• Dimensions: 15W | 9H | 10D inches
• Weight: 43 lbs.

Owner’s Manuals

MV75
MV75a

MV100 Vacuum Tube Power Amplifier

The MV100 vacuum tube power amplifier evolved from the Premier Four. The regulated power supplies were redesigned to improve the isolation between the input amplifier and inverter stages of the amplifier. The MV100 delivered 90 watts per channel by using two pairs of EL34 output tubes per channel.

Features:

• 4, 8, 16 ohm speaker taps (screw type)
• one pair of inputs
• two plate fuses (MV75A, and MV75A-1)
• power switch

Replacement Tube Set RT100

V1 & V2: 5751 | V3 & V4: 6FQ7 | V5-V12: 6CA7/EL34

Specifications:

• 90 watts per channel RMS at 4, 8, or16 ohms both channels driven from 30Hz to 15kHz with no more than 1% THD or IMD
• Input Sensitivity: 0.875 volts
• Frequency Response: 20Hz to 20 kHz, +0, -.5 dB
• Hum & Noise: 96 dB below rated power

Mechanical:

• Dimensions: 19W | 9H | 20.5D inches
• Weight: 80 lbs.

Owner’s Manual

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MV125 Vacuum Tube Power Amplifier

The MV125 vacuum tube power amplifier superseded the MV100. It was designed for audiophiles who had larger than average power requirements or less efficient speaker systems. The MV125 delivered 125 watts per channel using two pair of 6550 output tubes per channel. This amp debuted conrad-johnson’s trans-spectral output transformer design – a specifications for intricately interleaved windings that theoretically is capable of unlimited bandwidth, and in fact increased small signal bandwidth by several-fold. This design was later implemented in the Premier Eight, Eleven, and Twelve power amplifiers. Also in common with these later models, the MV125 used polypropylene capacitors for the main power supply reservoir.

Features:

• one pair of inputs
• two plate fuses
• power switch

Replacement Tube Set RT125

V1 & V2: 5751 | V3 & V4: 6FQ7 | V5-V12: 6550

Specifications:

• Stereo 125 watts per channel, RMS, at 4, 8, or16 ohms with both channels driven from 30Hz to 15kHz
  Input Sensitivity: 0.88 volts
• Frequency Response: 20Hz to more than 20kHz , +0, -.5dB
• Hum & Noise: 96 dB below rated power

Mechanical:

• Dimensions: 19W | 8.75H | 20.5D inches
• Weight: 80 lbs.

Owner’s Manual

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CAV50 Vacuum Tube Control Amplifier

Because each element of an audio circuit introduces its own sonic colorations, a simple circuit should be expected to yield superior musical performance. At conrad-johnson, we have maintained a commitment to designing simple, straight forward circuits for audio components. The CAV50 elevates this design philosophy from the circuit level to the system level by eliminating the preamplifier altogether and incorporating the control functions on the amplifier chassis, hence the term “control amplifier”. This approach completely eliminates the inherent colorations of the active circuitry embodied in a preamplifier stage, and of the cabling between preamp and amp. The result is a significant improvement in system performance and convenience, combined with a reduction in cost.

Many owners will appreciate owning a home audio system that is at once highly musical, yet easy to set up, and a model of convenience in use. Just add a high quality compact disc player, and a pair of monitor-grade loudspeakers for a true high-end audio system that makes minimal demands on your living space.

The attractive price of the CAV50 reflects the genuine cost savings achieved by eliminating the extra circuitry and chassis of a preamplifier.

Examination of the CAV50 will quickly reveal that we have not followed the trend to cut corners on parts quality to offer a cheap integrated amplifier masquerading as high-end product. Conrad-Johnson sets the standard for parts quality in the audio industry, and the CAV50 is no exception. High quality component parts assure full realization of the potential performance of the circuit design from new through many years of dependable use.

In the CAV50, precision, deposited tinoxide resistors yield low noise performance for greatest clarity.

Polypropylene and polystyrene capacitors, used exclusively in both the audio circuits and the plate voltage supplies, maintain temporal accuracy. Separate discrete voltage regulators supply dc voltages to the input amplifier and phase inverter stages. Oversized main and output transformers enable the amplifier to deliver high current bursts that are demanded by musical transients. The proprietary wide-bandwidth output transformers enable the CAV50 to cleanly reproduce extended high frequencies and fast transients. Industrial quality gas filled relays perform selector functions, permitting minimal signal path length and extended life. The precision tracking volume control maintains accurate channel to channel balance.

Benefiting from an uncommonly direct and short signal path, and a simple circuit executed with premium quality parts, the CAV50 dramatically outperforms its modest price. Harmonic structure, sound stage, dynamic contrasts, and dramatic impact are all reproduced with remarkable fidelity to the live event. Never imposing distractions, the CAV50 invites the listener to enjoy the musical performance.

Features:

• six line level inputs, including one tape loop
• built-in LED bias indicators for easy, instrument-free biasing of the output stage

Controls:

• volume
• source/monitor

Replacement Tube Set RCAV50

12AU7 | 2 12AX7 | 2 6SN7 | 4 EL34

Specifications:

• Amplifier Power (ultralinear operation): 45 watts per channel from 30 Hz to 15 kHz at no more than 1% THD, both channels driven into 4, 8, or 16 ohms
• Sensitivity: .50 V to rated power
• Gain (PRE OUT): 20 dB
• Phase (speaker outputs): phase correct (non-inverting)
• Phase (PRE OUT): phase inverting
• Frequency Response: 20 Hz to 20 kHz, +0/-.5 dB
• Hum and Noise: 98 dB below 45 watts
• Hum and Noise (PRE OUT):94 dB relative to 2.5 V output
• Input Impedance: 50 kOhms

Mechanical:

• Dimensions: 17.5W | 7.5H | 14D inches
• Weight: 44 lbs.

Owner’s Manual

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LP66S Vacuum Tube Amplifier

Consistent with conrad-johnson’s design philosophy that circuits should be kept as simple as possible, the LP66S works its magic with just seven vacuum tubes. A composite triode input stage is direct coupled to a cathode-coupled phase inverter – the same improved wide-bandwidth driver stage found in our other, more costly LP amplifiers. The output stage is comprised of a pair of 6550s (each channel) operated in ultralinear configuration for an optimal combination of high power and low distortion. Limited negative feedback is applied to the circuit to reduce distortion and provide a sufficiently high damping factor to control most real-world speaker systems. Discrete dc power supply regulators are provided for the input and inverter stages, in order to isolate each stage from the output signal.

As with all conrad-johnson tube amplifiers, the LP66S requires no complicated adjustments or specialized equipment to main­tain. To assure continued peak performance, the owner need only make a simple bias adjustment when new tubes are installed. Built in LED bias indicators allow the user to make this adjust­ment using only the supplied screwdriver.

Component parts quality is a signature strength of any conrad-johnson product.

Audio circuit and related power supplies feature precision metal film resistors and high-performance polypropylene capacitors. There are no electrolytic capacitors in the audio circuits or in the related power supplies. Proprietary wide-bandwidth output transformers contribute to excellent high frequency performance. Even the input/output connectors and internal wiring have been carefully selected for optimal sonic performance.

Conservatively rated at 60 watts per channel, the LP66S offers sufficient power for most applications.

Users who have not previously experienced the dynamic range and lifelike timbre of tubed components will find the LP66S an ideal introduction to the joys of modern tubed amplifiers. Along with its tonal integrity, its ease of use, low maintenance costs, and reliability will be a revelation for those who have only experienced “entry-level” tube gear. For veteran audiophiles, its modest price and size make it a great choice for bringing conrad-johnson quality to a “second” system. A word of warning if you are in this last group: whether in the den, library, or bedroom, the LP66S’ wide bandwidth and low distortion will give your main system a run for the money.

Specifications:

• Power: LP66S – 60 watts per channel from 30 Hz to 15 KHz at no more than 1.5 % THD or IMD, both channels driven into 4 ohms (also available connected for 8 or 16 ohm loads)
• Sensitivity: 0.5 V to rated power
• Frequency Response (at 10 watts): 20 Hz to 20 kHz, +/- .25 dB
• Hum and Noise: 102 dB below rated power
• Input Impedance: 100 kOhms
• Tube Complement: 3 x 6922 | 4 x 6550

Mechanical:

• Dimensions: 19W | 6.375H | 16D inches
• Weight: 45 lbs.

Owner’s Manual

LP66
LP66S2

LP70S, LP140M, LP275M Vacuum Tube Power Amplifiers

These new conrad-johnson linearized-pentode amplifiers are designed to meet the needs of industry professionals and audiophiles who seek audio perfection for their reference systems. While the demand for precision and musicality is the common denominator of these systems, the power requirements can vary considerably. To meet these varying needs, we offer the LP70S stereo amplifier rated at 70 watts per channel, the LP140M monaural amplifiers rated at 140 watts and the LP275M monaural amplifiers rated at 275 watts.

The LP amplifiers share the same basic audio circuit.

This circuit consists of three stages. The input signal is amplified by a triode amplifier. The signal is then direct coupled to a cathode coupled phase-inverter. This high current, triode phase-inverter stage provides a balanced, low impedance drive to the output stage. Output power is developed by 6550 output tubes, chosen for their musical accuracy, high power, and reliability. Each channel of the LP70S uses one pair of 6550s to produce 70 watts per channel, the LP140M uses two pair to produce 140 watts per each mono chassis, and the LP275M uses four pair to produce 275 watts. The output tubes are operated in ultra-linear configuration which offers an optimal combination of high power and low distortion. The massive conrad-johnson trans-spectral output transformers have intricately interleaved windings designed for extended bandpass and high phase linearity. A small amount (about 12 dB) of loop negative feedback reduces distortion and achieves a sufficiently high damping factor to control reactive loudspeaker systems.

Separate, low impedance, discrete dc power supply regulators are provided for the input and phase-inverter stages, preventing the output stage from modulating these stages through the power supply.

These power supplies are designed to maintain a rock solid supply at all audio frequencies. The main power supply reservoir uses a bank of massive custom polypropylene capacitors. No electrolytic capacitors are used in any of these power supplies.

These amplifiers require no complicated adjustments or specialized equipment to main­tain. To assure continued peak performance, the owner need only make a simple bias adjustment when new tubes are installed. Built in LED bias indicators allow the user to make this adjust­ment using only the supplied screwdriver.

At conrad-johnson we are fully aware that component parts contribute importantly to the sonic performance of any circuit design.

The LP amplifiers maintain the exacting quality standards for which con-rad-johnson is internationally known. Resistors are precision laser-trimmed metal foil types. Coupling capacitors are the new Teflon CJD caps and all other audio-circuit capacitors are polystyrene, while the power supplies use large value polypropylene in parallel with polystyrene capacitors. There are no electrolytic capacitors in the audio circuits or in the related power supplies. Proprietary wide-bandwidth output transformers contribute to excellent high frequency performance. Even the machined gold plated OFC connectors and the internal wiring have been carefully selected for optimal sonic performance. Attention to details of this kind enable us to extract the full potential from our circuit designs and ensure that our products will perform to this potential for years to come. Visit a conrad-johnson dealer soon to hear for yourself just how true to the music an amplifier can be.

Specifications

Power:

LP70S – 70 watts per channel from 30 Hz to 15 KHz at no more than 1.5 % THD or IMD, both channels driven into 4 ohms (also available connected for 8 or 16 ohm loads)
LP140M – 140 watts from 30 Hz to 15 KHz at no more than 1.5 % THD or IMD into 4 ohms (also available connected for 8 or 16 ohm loads)
LP275M – 275 watts from 30 Hz to 15 KHz at no more than 1.5 % THD or IMD into 4 ohms (also available connected for 8 or 16 ohm loads)

• Sensitivity: .5 V to rated power
• Frequency Response (at 10 watts): 20 Hz to 20 kHz, +/- .25 dB
• Hum and Noise: 102 dB below rated power
• Input Impedance: 100 kOhms

Tube Complement:

LP70S and LP140M — 3 x 6922 | 4 x 6550
LP275M — 3 x 6922 | 8 x 6550

Dimensions:

LP70S and LP140M — 19W | 6.38H | 16D inches
LP275M — 19W | 7.125H | 18.75D inches

Weight:

LP70S – 50 Lbs.
LP140M – 53 Lbs.
LP275M – 88 Lbs.

Owner’s Manual

LP70S
LP140S
LP275

LP125M Vacuum Tube Amplifier

Consistent with conrad-johnson’s design philosophy that circuits should be kept as simple as possible, the LP125M amplifier works its magic with a minimum of vacuum tubes (six). A composite triode input stage is direct coupled to a cathode-coupled phase inverter. The output stage is comprised of 6550s operated in ultra-linear configuration (two pair) for an optimal combination of high power and low distortion. Limited negative feedback is applied to the circuit to reduce distortion and provide a sufficiently high damping factor to control most real-world speaker systems. Discrete dc power supply regulators are provided for the input and inverter stages, in order to isolate each stage from the output signal.

As with all conrad-johnson tube amplifiers, the LP125M amplifier requires no complicated adjustments or specialized equipment to maintain. To assure continued peak performance, the owner need only make a simple bias adjustment when new tubes are installed. Built in LED bias indicators allow the user to make this adjustment using only the supplied screwdriver.

Component parts quality is a signature strength of any conrad-johnson product.

The audio circuit and related power supplies feature precision metal film resistors and high-performance polypropylene capacitors. There are no electrolytic capacitors in the audio circuit or in the related power supplies. Proprietary wide-bandwidth output transformers contribute to excellent high frequency performance. Even the input/output connectors and internal wiring have been carefully selected for optimal sonic performance.

Conservatively rated at 60 watts per channel, the LP66S offers sufficient power for most applications.

Users who have not previously experienced the dynamic range and lifelike timbre of tubed components will find the LP66S an ideal introduction to the joys of modern tubed amplifiers. For those who do require more power, the LP125M mono-block delivers a solid 125 watts. Along with the tonal integrity and faithfulness to the music that are embodied in these amplifiers, their ease of use, low maintenance costs, and reliability will be a revelation for those who have only experienced “entry-level” tube gear.

Specifications

• Power: 125 watts from 30 Hz to 15 KHz at no more than 1.5 % THD when driven into 4 ohms (also available connected for 8 or 16 ohm loads)
• Sensitivity: LP125M – 0.9V to rated power
• Frequency Response: (at 10 watts): 20 Hz to 20 kHz, +/- .25 dB
• Hum and Noise: 102 dB below rated power
• Input Impedance: 100 kOhms
• Tube Complement: 1 x M8080 | 1 x 6922 | 4 x 6550

Mechanical:

• Dimensions — 17.75W | 6.625″H | 13.375D inches
• Weight: 47 Lbs.

Owner’s Manual

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The LP125sa Stereo Amplifier and LP260m mono-block are the latest in the highly regarded series of conrad-johnson vacuum-tube power amplifiers.

The LP125sa offers a compelling combination of the audio excellence one expects from conrad-johnson, the convenience of a single stereo chassis, and, at 125 watts per channel, sufficient power for the majority of high-end speaker systems. Those with more demanding speaker systems will want to turn to the LP260m mono-block powerhouse, rated at 270 watts. Both amplifiers are capable of capturing the delicate textures and subtle nuances of live music while maintaining control with the authority that comes with ample power.

Nearly identical in both models, the audio circuit consists of three stages.

The input signal is amplified by a single-ended triode amplifier designed for wide bandwidth. The signal is then direct coupled to a cathode coupled phase-inverter. This high current, triode phase-inverter stage provides a balanced, low impedance drive to the output stage. Output power is developed by KT120 power tubes (two pairs per channel in the LP125sa, four pairs in the LP260m), chosen for their excellent sonic character, high power capability, and reliability. The output tubes are operated in ultralinear configuration which offers a desirable combination of high power and low distortion. Massive output transformers with intricately interleaved windings afford extended bandpass and high phase linearity. A small amount (about 12 dB) of loop negative feedback reduces distortion and achieves a sufficiently high damping factor to control reactive loudspeaker systems.

Power supply design is every bit as critical to the performance of an audio component as the audio circuit itself.

Separate, low impedance, discrete dc power supply regulators are provided for the input and phase-inverter stages, preventing the output stage from modulating these stages through the power supply.

These amplifiers require no complicated adjustments or specialized equipment to maintain. To assure continued peak performance, the owner need only make a simple bias adjustment when new tubes are installed. Built in LED bias indicators allow the user to make this adjustment using only the supplied bias adjustment tool.

Specifications

LP125sa

125 Watts per channel from 30 Hz to 15 KHz at no more than 1.5 % THD or IMD, both channels driven into 4 ohms (also available connected for 8 or 16 ohm loads)

LP260m

270 Watts from 30 Hz to 15 KHz at no more than 1.5 % THD or IMD, driven into 4 ohms (also available connected for 8 or 16 ohm loads)

Sensitivity

LP125sa – 1.1 Volt rms to rated power
LP260m – 1.8 Volt rms to rated power

Frequency Response (at 10 watts)

20 Hz to 20 kHz, +/- .1 dB

Hum and Noise

104 dB below rated power

Input Impedance

100 kOhms

Tube Complement

LP125sa – 1 6189, 2 6N30P, 8 KT120
LP260m – 1 M8080, 1 6N30P, 8 KT120

Dimensions

19D x 19W x 7.1H inches

Weight

LP125sa – 82 lb
LP260m – 83 lb

Owner’s Manual

LP125sa

Owner’s Manual

LP260

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Classic Sixty Vacuum-Tube Amplifier

Tasked with developing the most cost effective amplifier that we could build, consistent with our standards of quality of construction and performance, the conrad-johnson design team turned to our flagship product for inspiration.

Borrowing heavily on the technology of its big brother, the ART amplifier, the Classic Sixty preserves the distinctive tonal character of individual instruments and voices, with each clearly located within the overall acoustical environment of the original recording. Musical transients are reproduced with realistic impact, but without artificial enhancement. Like its more costly siblings, the Classic Sixty captures the emotional impact of the live event, never getting between the listener and the musical performance.

There really is no mystery to the basis for outstanding musical performance: best results come from simple circuits executed with quality parts.

The Classic Sixty amplifier circuit design is about as simple as possible, employing just seven vacuum-tubes. Single-ended triode voltage gain and inverter stages are coupled to an output stage comprised of a single pair of ultra-linear operated EL34 tubes for each channel. As it is critically important that the DC voltage supplied to the gain stages be absolutely rock-solid stable, these voltages are provided by simple but highly effective discrete voltage regulators. And speaking of simple, maintenance of the Classic Sixty could hardly be easier: the owner need only make a simple bias adjustment using the built in bias indicators when installing fresh output tubes.

The use of premium quality component parts is the other half of our underlying design mandate.

In this area as well, the Classic Sixty is a leader in its class. Precision, metal-film resistors yield low noise performance for greatest clarity. Polypropylene and polystyrene capacitors, chosen to achieve a high degree of temporal accuracy, are specified for both the audio circuits and the regulated plate voltage supplies for the input and inverter stages. The result is an exceptional range of dynamics – reproducing both subtle variations in level as well as dramatic loud crescendos. Our proprietary trans-spectral wide-bandwidth output transformers contribute importantly to the extended, “airy” highs that help distinguish the Classic Sixty from ordinary tubed amplifiers.

The Classic Sixty offers an ideal introduction to the joys of modern tube amplifiers, while the ease of use, low maintenance costs, and reliability will be a revelation for those who have only experienced “entry-level” tube gear.

Those who wish to take the experience a step further will want to investigate the upgraded Classic Sixty SE, which upgrades the output tubes to KT120s and incorporates CJD Teflon Capacitors and ultra high-performance metal foil resistors in strategic applications in the circuit. Either model is sure to rekindle your passion for enjoying great music in your home.

Specifications

Power

60 watts per channel from 30 Hz to 15 KHz at no more than 1.5 % THD, both channels driven into 4 ohms (also available connected for 8 or 16 ohm loads)

Sensitivity

0.7 V to rated power

Frequency Response (at 10 watts)

20 Hz to 20 kHz, +/- .3 dB

Hum and Noise

96 dB below rated power

Input Impedance

100 kOhms

Tube Complement

1 x 6189, 2 x 6922, 4 x EL34 (Classic Sixty)
4 x KT120 (Classic Sixty SE)

Dimensions

13.25D x 17.375W x 6.625H inches

Weight

41 Lbs.

Owner’s Manual

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The DF1 combined a superb line stage preamplifier with and integral CD transport.

An infrared wireless remote control was included. The DF1 could be used as a stand-alone CD player or as a unit combining the preamp and CD functions in a single chassis.

The DF1 was known for conrad-johnson’s superior imaging, depth, and soundstaging.

CD Player:

The DF1 CD mechanism uses a single laser beam that does not require alignment. The 176.4Khz sampling rate and noise shaping circuitry yield 16 bit resolution, and allow gentle filtering well above the audio frequency band. Digital to Analog converters are employed to eliminate phase shift between channels and avoid switching glitches.

Preamp Stage:

Unlike most CD players that use IC’s in the line stage, the DF1 uses discrete FET analog circuits with separate discrete regulated power supplies—circuits which have proven reliability and superior soundstaging and imaging.

The DF1 uses the highest quality component parts. Precision tin-oxide resistors, polypropylene capacitors and polystyrene capacitors and premium quality controls are used throughout the DF1.

Specifications:

Line Stage:

• Gain: 26dB
• Maximum Output: 5V
• Frequency Response: band-pass 5Hx to more than 100Khz
• Hum and Noise: better than 82dB below 1.0V output
• Distortion: less than 0.25% THD at rated output

CD Player (Direct Out):

• Output: 1.1V
• Frequency Response: 5Hz to 19Khz +0.5dB
• Hum & Noise: better than 85dB below 1.0V
• Distortion: less than 0.25% THD at rated output
• D/A Conversion: 16 bit resolution through 176.4kHz sampling, digital filtering

Mechanical:

• 19” Wide X 3 ¾” High X 12” Deep
• Weight 19 lbs.

Owner’s Manual

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The DF-2 combines data reading capabilities of the conrad-johnson DR-1 Data reader with sophisticated digital-to-analog conversion circuits from conrad-johnson.

The Digital Processor in the DF-2 utilized a bit-stream DAC, known for very low crossover notch distortion resulting in smooth, extended high frequencies without edginess. Discrete audio devices are used in the final analog output stage.

Precise adjustments were made to the laser intensity and focus to assure accurate data retrieval. A sophisticated crystal controlled “re-clocking” circuit in the DF-2 reduced jitter by an order of magnitude.

DC voltage are supplied to the audio stage and analog portion of the DAC chip by discrete regulated power supplies, using “cjd” polystyrene and polypropylene capacitors exclusively.

Features:

• Infra-red wireless remote control
• 30 track programming
• digital volume control

Specifications:

• Output: 1.0VRMS
• Bandpass: 5Hz to 20Khz +0.5dB
• Hum & Noise: better than 925dB below 1.0V
• Distortion: less than 0.05% THD at rated output
• Phase: 0, 180 degrees of phase shift, switch selectable
• Outputs: one pair of RCA analog outputs and one coaxial digital output

Mechanical:

• 19” Wide X 3.315” High X 14 3/8” Deep
• Weight 19.5 lbs.

Owner’s Manual

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The D/A-1 was a digital to analog converter using FET analog circuitry.

Data filtering in the D/A-1 is done by a digital linear phase filter. This filter was chosen because offered very low ripple, and an imposing 100 dB of rejection of the stop-band. It also handles the final error correction. Other filtering systems tended to sound much harsher.

Data Conversion is accomplished by a bit-stream DAC chip. Bit-stream chips offer the most musical performance, especially in the critical mid- and high-frequency ranges, contributing to the D/A-1’s smooth, extended highs.

Analog filtering is done in the final stage of the D/A-1. This stage is a low-pass filter, designed to remove high-frequency (supersonic) artifacts of the conversion process. The analog stage is a second-order Bessel filter and buffer circuit using jfets, tin-oxide resistors, and all polypropylene and polystyrene capacitors.

The power supplies in the DA/1 are critical to the overall design. Separate discrete, regulated power supplies power the output filter and the analog circuits in the DAC. These power supplies use polypropylene and polystyrene exclusively. Separate power transformers, and a shielded compartment isolate the analog stage from the digital circuitry.

Specifications:

• Sensitivity: 1.0VRMS output at 0dB(maximum output)
• Band-pass: 5Hz to 20KHz, +0. -.5dB
• Hum and Noise: better than 92dB relative to1.0V output
• Distortion: less than 0.05% THD
• Phase: 0, 180 degrees of phase shift, switch selectable
• Inputs: BNC and RCA Coaxial, TOSlink optical, ST Glass optical optionally available
• Output: BNC

Mechanical:

• 19” Wide X 3.315” High X 14 3/8” Deep
• Weight: 16 lbs.

Owner’s Manual

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The division of compact disk playback systems into a separate transport and digital processor allows each unit to be carefully optimized for its specialized task, and also allows access to the high performance digital processor for other sources, such as a digital tape recorder or laser disc player. The DR-1, D/A-2b, and D/A-3 offer two conrad-johnson cd playback systems for listeners for whom musical performance is the most important criterion.

DR-1 Compact Disc Data Reader

The task of a compact disc transport is to recover the binary data encoded on a cd and to accurately transmit that data to a digital to analogue converter. A stable platform for the mechanism is vitally important to allow accurate reading of the data. For this reason, the DR-1 is housed in a sturdy, mass loaded chassis. The smooth, quiet operation of the DR-1 is an added benefit of this design.

To assure accurate data retrieval, precise adjustments are made to the laser intensity and focus.

Any variation in the timing of the data stream will lead to distortion in the analogue audio wave form, so the data must be transmitted at a precisely correct and unvarying rate. Deviations in this rate are called “jitter”. A sophisticated crystal controlled “re-clocking” circuit in the DR- I reduces jitter by an order of magnitude.

The D/A-2b and D/A-3 Digital Processors

A digital processor accepts the data stream from the transport and converts the numerical data back into music. Several circuits are involved in this process. Of these, data conversion, analogue filtering and power supplies are particularly important to faithful music reproduction.

We have chosen to use bit-stream DAC chips for these processors because we find that they offer by far the most musical performance. The edgy, unmusical sound that we typically find with multi-bit DACs is probably attributable to a type of crossover-notch distortion which is intrinsic to these designs, and absent from bit-stream converters. This distortion is essentially invariant to signal amplitude, making it most noticeable on delicate musical passages, obscuring ambience information, tonal nuance, and harmonic subtlety The bit-stream approach reproduces these important elements of musical information far more naturally

The final stage of any DAC is the analogue output stage. This stage is a low-pass filter, designed to remove high-frequency (supersonic) artifacts of the conversion process. In the majority of units presently on the market, this critical function is performed by an IC op-amp, with much the same result as would be expected from using that device in a preamplifier. In contrast, the output stages of the D/A-2b and D/A-3 are designed and executed in much the same way as our preamplifier circuits, using discrete devices – the D/A-2b using vacuum-tubes, the D/A-3 using field-effect transistors.

Always important, power supply des critical to the musical performance of a tal processor, because of the need to isolate the sensitive analogue audio stages from the very high-frequency noise generated in the digital sections. In the D/A-2b and the D/A-3, dc voltage is supplied to the audio stage by a discrete regulated power supply, designed to offer vanishingly low impedance at all audio frequencies. These power supplies use polypropylene and polystyrene capacitors exclusively A similar, separate regulator supplies DC to the analogue circuits in the DAC chip – the origin of the audio signal.

The DR-1, D/A-2b and D/A-3 have been designed and produced with care to transform digital sources into a musically rewarding experience. These digital playback systems offer depth and focus of soundstage, tonal accuracy, and an ability to convey nuance in musical performances that many audiophiles have felt would not be possible from compact disc.

DR-1 Compact Disc Data Reader

—Introduced February, 1996

Specifications:

Outputs: One RCA coaxial output.
Professional Output Option adds one ST Glass optical output and one AES/EBU output.

Features:

• Infra-red wireless remote control
• 30 track programming
• digital volume control

Mechanical

• Dimensions: 14.375D x 19W x 3.315H inches
• Weight: 17 lbs.

D/A-2b Vacuum-Tube Digital Processor

— introduced September, 1995

Specifications:

• Sensitivity: 1.0 VRMS output at 0 dB (maximum output)
• Distortion: less than .05% THD
• Bandpass: 5 Hz to 20 KHz, +0, -5 dB
• Hum and Noise: 92 dB relative to 1.0 V output
• Phase: 0, 180 degrees of phase shift switch selectable
• Inputs: One RCA coaxial, one BNC coaxial, one TOSlink optical. ST Glass optical input is optionally available.
• Digital Output: one BNC coaxial

Mechanical

• Dimensions: 14.375D x 19W x 3.315H inches
• Weight: 19 tbs.

D/A-3 FET Digital Processor

—introduced March, 1996

Specifications:

• Sensitivity: 1.1 VRMS output at 0 dB (maximum output)
• Distortion: less than .25% THD
• Bandpass: 5 Hz to 20 KHz, +0, -1 dB
• Hum and Noise: 95 dB relative to 1.0 V output
• Phase: 0, 180 degrees of phase shift switch selectable
• Inputs: Two RCA coaxial, one TOSlink optical. ST glass optical input is optionally available.
• Digital Output: one RCA coaxial

Mechanical:

• Dimensions: 14.375D x 19W x 3.315H inches
• Weight: 14 tbs.

Owner’s Manuals

DR-1 manualD/A-2 manualD/A-3 manual

The HD3 is an audiophile grade digital to analog converter for use with a computer based audio source. It is designed to exploit the advantages of the recently available high-definition digital source material, to be simple to use, and to establish that digital sources really can “just sound right”.

The HD3 is designed to be as hassle-free as possible.

Connect it to any available USB port on your computer with a standard USB cable, select the HD3 and you should be ready to play music in a matter of moments. It is designed to work with the drivers built into the operating systems of all modern PC, Mac, and Linux computers, so there is no need to struggle with installing drivers as there are none to install. Just select your favorite tunes from music stored on your computer, or pop a CD into your computer’s optical drive, sit back and enjoy.

With its asynchronous data interface virtually eliminating jitter, the HD3 will transform your computer into a high-end CD player competitive with the very best audiophile quality units on the market. But it will do much more than that. By “ripping” your CDs to the computer you can take advantage of software that makes multiple read passes to virtually eliminate data errors, for superior playback. You can store an entire music collection on the hard-drive of your computer, and use your choice of “juke-box” software to search for and select the songs or albums you want to play. Preserve your CDs from possible damage in handling by copying them to your hard drive and putting them away in safe storage. Imagine a couple of thousand or more CDs of music all contained in the space of a small computer. Better yet, the HD3 is designed to deliver better than CD quality material. It will decode up to 24 bit, 96k samples/second music files. These files are available for purchase by download from various on-line sources.

The conrad-johnson analog audio circuits are your assurance that the HD3 will deliver the full potential of these sources and in the end, the music playback will be musical.

As expected from conrad-johnson, the circuits are simple and executed with quality parts. A high-end Burr-Brown delta-sigma dac was selected for the digital to analog conversion. This is the most musically satisfying 24/96 capable dac presently available. The analog signal is fed to our own audio circuits, executed with highest quality polypropylene capacitors and metal foil and metal film resistors. The digital circuits are powered by regenerating power from the USB connection itself, while the analog portion of the dac and the analog audio stage are powered by separate transformers feeding discrete dc voltage regulators, thus isolating the analog signal from noise imposed on the grounds and power supply legs of the digital circuits.

Better sound and quicker, easier access to all your music, what is not to like?

Specifications:

• Output level (0 dB): 3.5 Vrms
• S/N Ratio: better than 100 dB
• Frequency response: 2 Hz to 20 kHz +0/-1.0 dB
• Total harmonic distortion: less than 0.05%
• Dimensions: 10″W, 2.75″H, 13″D
• Weight: 7 lb

Owner’s Manual

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The MF80 was the first solid state power amplifier bearing the conrad-johnson name. It was soon followed by the very similar, but more powerful, MF200 FET.

These amplifiers were the result of more than a decade of research by conrad-johnson into the application of solid-state devices to the reproduction of music.

The MF80 & MF200 used a similar circuit and differed in their power output-the MF80 delivered 80 watts per channel RMS & the MF200 delivered 200 watts per channel RMS. FET’s (Field Effect Transistors) were chosen as the basic circuit element of these designs because of their absence of the annoying odd-order harmonics that plagued so many transistor designs. Minimal negative feedback was used which obviated the typical overshoot and ringing associated with the “transistor sound” of other amplifiers. Parts specification met cj quality standards throughout. All capacitors were polypropylene and cjd polystyrene with the exception of the power supply filter caps. All resistors were 1% metal-oxide deposited on glass construction.

The MF80 & MF200 achieved astonishing results for solid state designs and were often compared with the top tube amplifiers of the day.

Specifications

Power:

MF80 – 80 watts per channel from 20Hz to 20KHz with no more than 1% THD or IMD, both channels driven into 8 ohms.

MF200 – 200 watts per channel from 20Hz to 20KHz with no more than 1% THD or IMD, both channels driven into 8 ohms.

Specifications:

Input Sensitivity: MF80 – 1.3V | MF200 – 2.2V
Frequency Response (at 10 Watts): 20 Hz to 20 kHz, +0, -.5 dB
S/N Ratio: MF80 96 dB, MF200 98dB relative to rated power

Mechanical:

Dimensions (MF80) – 19″ X 5″ x 12.63″
Dimensions (MF200) – 19″ X 8″ X 15.63″

Weight: MF80 – 38 lbs. | 50 lbs.

Owner’s Manuals

MF80MF200

These amplifiers share the same basic JFET input stage and MOSFET output stage as introduced in the earlier MF80 and MF200.

The new amps increased the number of output devices (MF80 used one pair, the MF200 two pair, the MF 2100 two pair, MF2200 three pair, and the MF2300 four pair). The MF2100 and MF2200 differ only in power output whereas the MF2300 might best be thought of as an MF2200 on steroids.

The MF2300 is rated 240 watts per channel, however it’s most significant advantage is its ability to deliver one third more current into low impedance loads, making it the ideal choice to drive a number of highly regarded but difficult to drive loudspeakers. The MF2300 also uses all polystyrene capacitors in the audio circuit, machined gold-plated OFC input connectors, and premium quality machined output binding posts.

After two years, the MF2300 was improved by the use of Vishay resistors at critical points in the circuit, extending the open-loop frequency response of the circuit, and upgrading capacitors in the input amplifier power supplies. The improved model was designated MF2300A.

Features:

• Power switch
• Left and right RCA input jacks
• Left and right output jacks (5 way binding posts)

Specifications

Power Output:

MF2100 – 100 watts per channel
MF2200 – 200 watts per channel
MF2300 – 240 watts per channel
All deliver their power from 20Hz to 20KHz at no more than 1% THD and IM, both channels driven into 8 ohms.

Response: bandpass 20Hz to more than 20kHz , +0, -.5dB
Hum & Noise: 98 dB relative to max output

Mechanical:

MF2100 – 19″ X 4.31″ X 13 7/8″
MF2200 – 19″ X 5.2″ X 16 7/8″
MF2300 – 19″ X 6″ X 16 7/8″

Owner’s Manual

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The MF2250 and the MF2500 offered audiophiles a choice of power level in stereo amplifiers while the MF5600 was a five-channel amplifier.

The overall circuits in these amplifiers used a combination of FETs, and bi-polar transistors. FETs were chosen for the gain stage because like tubes and unlike bi-polars, they produce almost no strident odd-order harmonics. Bi-polar devices were specified for the output stages of these amplifiers for their low output impedance, resulting in improved bass response.

Specifications

Power Output:

MF2250 – 120 watts per channel
MF2500 – 240 watts per channel
MF5600 – 120 watts per channel
All deliver their power from 20Hz to 20KHz at no more than 1% THD and IM, both channels driven into 8 ohms.

Response: bandpass 20Hz to more than 20kHz , +0, -.5dB
Hum & Noise: 100 dB relative to max output

Mechanical:

MF2250 – 19″ X 4 ¼” X 16”
MF2500 – 19” X 6 ¾” X 16”
MF5600 – 19” X 8” X 16”

Owner’s Manuals

MF2250
MF2500
MF5600

The CA200 is in many ways the ultimate embodiment of our corporate design philosophy that simple circuits yield best results.

Its audio circuit consists of a single voltage gain stage followed by a high-current buffer/output stage able to deliver nearly 200 watts per channel into 8-ohm loads. The amplifier circuit is similar to our highly regarded Premier 350, using conrad-johnson’s auto-linear j-fet voltage gain circuit and a high-current bi-polar output stage to achieve low distortion and a high damping factor with zero loop negative feedback.

The CA200 adds a discrete stepped attenuator level control and input selector switches (all operable by remote control) to eliminate the need for a preamplifier. In fact, there is no line-stage integrated into the CA200 – hence the term “control amplifier”.

Similar in function to an integrated amplifier, a control amplifier offers the significant potential improvement of eliminating superfluous connections, external cabling, and inter-device connection considerations that limit conventional audio systems. But the control amplifier also eliminates an entire stage of audio circuitry (the line stage) and its inherent colorations.

Most integrated amplifiers not only forgo the advantage of eliminating superfluous circuits, but also are cheapened to offer a low cost entry into a prestigious brand, thereby failing to achieve even the performance gains that could be afforded by integrating preamp and amp into a single package.

By contrast, the CA200 circuits incorporate top quality parts (metal foil resistors, polystyrene and polypropylene capacitors, machined gold-plated connectors, etc.) to fully realize the dramatic potential of a control amplifier to enhance the immediacy of musical experience afforded by fine recordings. As a result, the CA200 is notable for its resolution of subtle dynamic shadings and palpable imaging, for a natural harmonic tonality, and extraordinary resolution. A half-scale version of the Premier 350 amplifier at the CA200’s price would be an excellent value. Add in the full switching and level control functionality of the control amplifier and it can be seen to be a genuine bargain.

Specifications

Power:185 watts per channel RMS both channels driven into 8 ohms from 20Hz to 20kHz at no more than 1% total harmonic distortion or intermodulation distortion.
Sensitivity: .32Vrms to rated output
Small Signal Distortion: less than .1% at mid-band
Frequency Response: 20Hz to 20kHz +0/-.5dB
Hum and Noise: 102dB below rated output
Phase: speaker output is phase inverted, preamp output is phase correct
Input Impedance: varies with level control setting, 12k Ohms minimum

Mechanical:

Dimensions – 15.5″D x 19″W x 3.315″H
Weight: MF80 – 38 lbs.

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