CatSynth pic: Analogue Synthesizer ETI project

From an auction, via matrixsynth:

(The original post has a larger pic of the synth)

This ETI Synthesizer project was built around 1979 by my father, the modules all worked when I powered them up recently (the original keyboard and power supply is not available due to someone connecting the mains to a +/- 12Volt input!) The modules consist of :

4 x VCOs
2 x VCFs
2 x VC Variable state filters
1 x Reverb unit
2 x VC Mixers
1 x Noise/Sample & Hold module
1 x DRF
1 x Ring Modulator
2 x Dual ADSR modules
2 x Dual VCAs
1 x Dual Envelope Generator
1 x VC Envelope Generator
1 x D-A Convertor
1 PA (not tested)