Vintage DIY Modular Analog Synth

via this auction

"I purchased this sweet guy at a yard sale and started working on it but I really have too many projects. It is a clearly homemade but nice quality modular analog synthesizer from the mid-1970's. This is an awesome piece for the collector! Vintage components are used throughout for maximum analog mojo. There are multiple components to this system. Here's a description of what is included:

1.) KEYBOARD CONTROLLER The keyboard controller is a two octave keyboard that is made from a chopped-off upright piano! This give it a really nice, unique feel. It has CV and gate outputs.

2.) TWO MODULAR CABINETS The two modular cabinets include three VCO modules (V/oct near as I can tell), a module with two summers and a noise source, a quad VCA module, a filter module, an ASDR module, a mixer module, and a power supply module (+/- 15V). The modules are chock full of vintage metal can CA3080 OTAs and other cool components. All jacks are RCA. The cabinets are made from pine and plywood for maximum 1970s homemade vibe.

3.) LARGE PILE OF RCA PATCH CORDS Various lenghts to match the RCA jacks used on the modules

Here is a list of what I have done to this synth since I bought it:
- Cleaned the keyboard contacts and set the keyboard potentiomenters for V/octave response.
- Cleaned all module potentiometers to remove nasty grease from pot shafts (I noticed when taking the pictures that a few (2-3) of the pots are still nto turning quite freeley. I managed to get the rest woring well with pot cleaner so I am sure that is all they need)
- Replaced a bad rotary switch in one of the VCO modules
- Verified the operation of the power supply, labeled power bus, and replaced some broken wires.
- Verified that all modules do not release any magic smoke when power is applied
- Verified that all modules work with the exception of the filter (lack of time on my part, plus I can't figure out the connections)
- Made some cool noises"