Conrad-Johnson factory model upgrades install the same parts and circuits that were incorporated in the latest or upgraded model version. An upgraded unit is electrically the same as the original production model.
We offer the following model upgrades:
| Classic to Classic SE |
| PV14L to PV14LS2 |
| Premier 15 to Premier 15 Series2 |
| Premier 16 to Premier 16 Series 2 |
| Premier 17LS to Premier 17LS2 |
| ACT2 to ACT2S2 |
| ART to AT Series 3 |
| ART Series 2 to ART Series 3 |
| MF2250 to MF2250A |
| MF2500 to MF2500A |