Panasonic WP-9220

[rf7]

Does anyone know of a cheaper alternative to the potted discrete Panasonic MC8134 opamp? It's a potted little circuit board with 2 8 pin dip IC's and 10 leads coming out of it.. Panasonic wants $50 for it.

[Enzo]

Got a schematic? Make the little circuit up on a small board.

Does MCM happen to have it in their manufacturer specific listings?

[rf7]

There's no actual schematic for what is inside the thing. It's drawn as an instrumentation amplifier in general, but it's got 4 rails coming in: +18V, +36V on two pins, -18V, and -36V on two pins also. It's some kind of arrangement where the +18V rail moves up to +36V on the positive peak and -18V moves down to -36V on the negative valleys. It's got 10 pins. I can see through the potting material that there are 2 IC's in it along with other stuff.

MCM does not have it. The only place I've found it is from Panasonic directly. Supposedly it is the Achille's heel of this amp.

[Enzo]

So is it a power amp IC? Acting as a driver or something?

I googled it to see what it was, and I found one selling for $190, and another that sold for $75. SO I can see why you wouldn;t want to buy a $50 part for it.

[J M Fahey]

Do you have the actual *power amp* schematic?
As Enzo said, it's probably a driver chip , it *might* be functionally replaced by something equivalent.
Worst case 1: if it drives (and biases) , say, 2 or 4 complementary power transistors (á la LM391), maybe you can build a classic amp "front end" on a small board.
Easy if you don't need short circuit protection as in a combo amp; otherwise that complicates the issue.
Worst case 2: you just ditch the entire power board and use those +/-36V to feed a regular amp or even a chipamp, using the original PSU and heatsinks.
Post some gut pictures.

EDIT: disregard my suggestions, it's a 300Wpc monster. Class H or F. Forget it.
If I had it in Argentina, I might mount a couple of my own PCBs inside and sell it for a reasonable profit, given that Ramsa/Panasonic carries some good vibes here, but in the American Market, it's not worth it.
Sorry.