Fresh off the bench is this Arp Odyssey. Previously owned by our head synthesizer tech, this Diabolical Device is sure to turn some heads. His notes are as follows:

Before I got this synth it had been modified twice, the second tech removed original mods (plugged 1/4 holes) and added 1/8" jacks for CV/Gate I/O and audio input with level control but It still wasn't quite right because of how the 2800 trigger/gate operate so I reconfigured it some and cleaned things up a bit. All the faders were replaced as well. 
CV/GATE in and out on rear panel work as you would expect except there is a switch on the top left of panel which assigns the incoming gate to either AR or ASDR. *The switch must be down for the 2800 keyboard gate/trigger to behave normally. These rear panel jacks are labeled.
1/4" and 1/8" jacks above potentiometer are audio inputs and the potentiometer sets its level.

Modifications I added: Front panel mounted 1/8" jacks in a similar arrangement as the ARP 2600. CV inputs replace original CV as selected by corresponding switch with what is plugged into the jack and then to CV level controls as would the original CV.

PANEL INPUTS:

VCO1- FM and PWM

VCO2- FM and PWMS/H- Mixer Input 1

VCF- Mixer Input 3 and VCF Freq

PANEL OUTPUTS:

VCO1 and VCO2- SQR and SAW outputs

LFO Output

VCF Output (pre VCA)

In addition to MODs I: Replaced power supply capacitors and remaining Tantalum capacitors with electrolytic type. Cleaned Keyboard buss bars and key contacts. * this unit uses "3 Buss" keyboard