Suitcase - what type of amps were there? Trying to identify

[Krischu]

I have the innards of a suitcase piano in front of me. My job is to inspect and potentially repair it.
I know Fender Rhodes stage pianos and also remember to have played on an 88 suitcase couple of years ago.

What I have here are the following pieces:

a Preamp with three pots. One of them seems to have a pullable axis.

2 power amp modules, each having a cinch input

I'm attaching a photo of the front panel. The P.T. is 230V already. The Euro C13 plug has been added by me (3D printed adapter).

[spave]

The name of the system for that panel is the "Peterson" if you look up "Peterson preamp" or Peterson power amp" here or online you should be able to find the information you're looking for on them.

[Krischu]

Thanks. Difficult to find a direct link to the schematics. I found a large PDF "Rhodes Service Manual" elsewhere (don't remember where I actually got it from) P/N 34-0119-000 and there on page 11-14, 11-15 is something called 80 Watt Suitcase, Peterson Design.

This looks like it fits the hardware I have here.

I'm trying to understand the circuit diagram. In Figure 11-9, upper right corner, there is a signal (collector of 2N3591) that is designated "From Power Supply". Where does it come from or go to?
(just to understand it). Is there a diagram showing the cabling between the power module(s) and the power supply/main panel?

[Krischu]

Now I'm a bit further. I powered the amp first time. It was stated that the amp worked. I measured the DC voltages and it turned out though +/- 35V were fine (37V, but that was with no modules connected), the 25V were not there, just 2.4V and no reaction when pot got turned a bit.

2N3392 ok, DELCO 020725 measures C/E short. Now I'm asking for equivalent.

[Alan Lenhoff]

https://retrolinear.com/rhodes-germanium-power-transistor.html