[sdiy] Prophet 10 op-amp swaps?

[Eric Frampton]

On Jul 10, 2013, at 5:06 AM, Oakley Sound <oakleylist at btinternet.com> wrote:

> It's been a while, but I replaced all the EQ op-amps with OPA134s on my old P10. I also did some other things too but I'm not sure of the details now.

The LM4562 that Paul S. recommended is actually a dual op-amp (silly me!), so I've got some of the single version, the LME49710, on order.

I swapped out the LF356 in the EQ section on the Upper board, and left Lower alone for comparison. Just dropping a TL071 in that spot (until the 49710's arrive) made a huge difference. Can't wait to see what swapping all the rest of 'em out - and with the better part - could do.

> I'm assuming those six 560K resistors on the outputs of the balanced output drivers on the schematic are actually 560R. If they are really 560K, I'd get them swapped out straight away.

Good catch. The schemo is labeled wrong, and they really are 560R as installed.

e