ARP Odyssey MkII Analog Synthesizer

via this auction
SN 2813 1715

"This is an ARP Odyssey MkII (black and gold) synthesizer with the 4075 filter...

- It was originally set up to be duophonic, where two voices would play if you pressed two keys at once, but I have it set up to be monophonic, with both oscillators on the same pitch.
- The filter originally cut off at too low of a frequency because the designers miscalculated the value of a resistor (see here), and I fixed it.
- I added a switch to let the LFO free-run instead of being re-triggered with each key press.
- It came from the factory with triggering on every keypress and an exponential glide (e.g. the same time to glide between any two notes). I modified it to be able to trigger like a Moog, where notes played legato do not trigger the envelope. This is switchable with a switch on the back (see the photo album). In addition, I modified the glide to be linear like a Moog. You can hear how this sounds in the clip above. Note that you would probably want to reverse these modifications if you wanted to trigger the synth with an external MIDI-CV converter.

All these modifications would be fairly straightforward to reverse if you so desired, and I kept the original parts, which I will provide with the synth."

Pics of the inside below.