Conrad Johnson PV12 AL

Hopefully hifiman5 will weigh in here as he has one that was modified and he is quite happy with it.  Good luck.  Regards......

I have had my PV12L extensively modified by Bob Backert of RHB Dezigns.  He focused on the power supply section of the line stage, bypassed the circuit board  traces with gold coated silver wire and added bypass boards to improve the performance. It is still a cj at heart but is more open sounding with a tighter more responsive bass response.

The PV12 used a 3 stage power supply. A pre-regulator fed a separate regulator for each side.

In addition to putting in better caps, or bypassing existing, adding some heat sinks to the regulators (really just transistors) could be useful in increasing reliability.

Also the resistor used in the power supply CRC circuits could be improved.

I’m really not a fan of mixed-metal conductors though.

Best bang for the buck on those is really the output caps though. They make much better caps than the PV10/12s had. If you are a noob, start there. :) Watch the cap voltage ratings carefully though.

Best of listening!

Erik