This one is from the first months of production and it had the high frequency noise as all the early units. Twelve years ago I had another PS-2 from a later production year and it sounded so much better.
So I did what the original service manual says. I swapped an electrolytic capacitor and added two mylar capacitors according to this:
I was lucky to have a few 4.7nF (0.0047µF) capacitors in a spare circuit board of a faulty KORG PME-40X modular effects system. They were perfect for this situation:
I only had a quite big 470µF electrolytic capacitor, so I used heat shrink tube and left the legs in almost original length. There is just enough space to bend the capacitor horizontally and place it next to the ribbon cable:
Now it sounds just as good as the later units. I can only recommend this easy modification and I don't think that the pedal lost its value this way. Just the opposite!
There are two trimpots inside. In the service manual are instructions how to properly calibrate these:
This does only affect mode 4 (Manual). If the adjustments are exactly done as described, you can shift the pitch 13 semi-notes each up and down. You only have to do this calibration
a) if you cannot dial in an octave pitch shift up or down or
b) if the value for same pitch (Tuner Out = C3) cannot be achieved with the "Fine/Manual" knob in center position (12:00h).
