Recent content by RadioMan

I have fixed some of the Carver magnetic field stuff in the past but never worked on a PL400/500/700 before. What I will say is this looks like a “Fly By The Seat Of Pants” amp design. What I see is a design that uses the least amount of parts possible to deliver good sound but the design has...

No offence taken I kinda agree.

What have been the solutions for this in the past?

I think I may experiment with lead dress and move the audio wires away from the power wires and see what happens. BTW where can I get a replacement power switch for a 4000II preamp?

It looks like a break in the photo but it fine. I went a reflowed all the connections on the rear of the unit and still no luck?

Switch in normal. Position makes no difference.

Switch in normal. Position makes no difference. Anyway here are some pics…

This is the craziest thing have experienced in a while. The amp works perfect if you keep the pots open all the way. Full power No noise sounds great. I see all the audio ground wires tie together near the input connectors, all looks goo there. I have looked for broken traces in the control...

I check everything as you stated and all check out fine. Pots read 100K as they should and have continuity throughout there range no dead spots. All wires look to be connected correctly in fact it looks all stock from the factory. I even re-soldered all the grounds in case of cold solder joint...

What pictures would be most helpful and I'll send them soon? Just to clarify, So for example when I short the RCA inputs and move the volume pots to ½ way or 50% I get the most buzz. When the pots are fully open or fully closed the buzz goes away. It should not make any noise no matter what...

All I did was change electrolytics. And the 2 7.5K power resistors as they were open. I did not move any wire harnesses. The amp it totally silent with the pots closed. And with the pots all the way up connected to the preamp the amp sound great and is quiet? Totaly Lost :(

It was dead when I got it now it works great with full out put but have this noise issue. Has new WO filter caps installed. Seems like a ground loop but don't know how that would happen?

I have PL700II that has been fully recapped and serviced but have a strange issue with hum/buzz sound. With a preamp connected when I rotate both volume pots on the amp to 50% I get hum/buzz sound. When I turn the pot all the way up the noise goes away. The same is true when the posts are fully...