Thanks Perry. I just figured because it was an old amp they were BJT's. Thanks Twilliar for that info. I found someone who has these but I figure something newer would be better and they want a lot of pesos for them. While i'm here how do you guys feel about using Higher UF and slightly lower voltage Pwr supply only caps on a PPI Art A200? its got 4 caps, all 85c 1000uf 50v
Thanks for that guys. I asked because another tinkerer said using caps rated at higher voltages increased the ESR. He used lower voltage caps on the PS supply of an A400 than came with it. With only 2 PS caps and two Output theres not many options here. At least its a lot easier than re-capping a later powerclass amp with its bazillion caps.
A higher voltage rating typically lowers the ESR. That can be good where there is high ripple current but that's typically only on the primary side and not generally an issue (engineers used what was needed). Where it is a problem (like on some of the early Rockford amps - BBQ pit style era?) you will repeatedly see all of the primary filter caps blown. There, you will see that Rockford used 63v caps where 16v caps would have been good enough if ripple current wasn't an issue.
Unless you have a real reason to change the part from what the engineer thought was needed, use the same value (higher voltage doesn't hurt but isn't likely needed). They are rarely wrong.
Some amplifiers are tough on primary side caps and 105C caps are sometimes used there. On the secondary side, 105C caps are rarely any better.If 85C caps fail on the secondary side, there is likely another problem (like when drivers fail in class D amps).