via this auction

Instead of making another clone arp 2600, I wanted to make an updated synthesiser, like an Arp 2700 type of project.
So there are many extra functions on this system, not found on the original arp2600. The only Arp 2600 circuit that is an exact clone, is the Analog Switch.
All the potentiometers are metal knurled type. Knobs are soft touch Black and White.
There are no internal patches. All connections must be manually made between module sections, this is a fully Modular System.
The only modules I did not include are: Reverb FX and Internal Speakers.
(These take care of the Reverb FX and Speakers situation.)
The FX send and Return module lets you patch a stereo fx rack or pedal. I felt this was better than using an old noisy Spring Tank.
The monitoring 1u module lets you patch a stereo cable to a JBL portable speaker for example for monitoring.
The monitoring amp can also be used for headphone monitoring.
In a room full of synthesizer systems, the Darpa Modular Synth will always turn heads or get asked "What about this one?". It is just a gorgeous looking instrument.