Indeed. Of all the synths I’ve opened, ARP’s are the most unpredictable. 2600s are almost always potted (except the final iteration) so who knows what lurked inside that epoxy? However, the Odysseys were never potted and of the four (supposed) Mk2s I’ve owned, not a one had the same guts. Heck, I had a Mk2 that was entirely a Mk1 in a Mk2 case, and I’ve had two Mk2s with close serial numbers that had completely different oscillator circuits. Now, any of these might have been built, “restored”, or repaired with whatever parts were on hand, and that only adds to the head-scratching.
And then there are the potential mods! My current 2600 is a crow’s nest of fragile wires and dangling daughter boards, giving me no desire to get in there and fix its few issues (I repaired a broken VCA, noise generator, and replace the power supply, but it was scary business).
Mind you you, I have little idea how any of it works, so I wouldn’t attempt to understand the actual circuitry. Luckily, there are smarter people than myself around. Speaking of which, what are you doing Saturday… 