The CAT

The Cat is a monosynth not unlike the ARP Odyssey or Axxe. It is monophonic but an update (SRM) added duophonic capability and a 2 note S&H for each of the two voices. The keybard could be switched from poly (2) to mono (1 oscillator). It has 1 LFO, 1 Filter, 2 envelope generators (AR and ADSR) and 1 VCA. It was produced from 1976 to 1981.

There are 4 versions of it:
* plain original Octave Cat:

Both VCF and VCOs were discrete. The frequency responce was a bit
worse compare to the later models (20Hz-20kHz). Soundwise it is
much dirtier and grungier. There was no delay control on the LFO,
no LFO indicator light. LFO had a narrower range. Some of the models
did not have any external control. Cosmetically it had a little bit
different color of wood and totally different minimoog-style black
knobs (which were later substituted by greyish ugly looking ones).

* Cat SRM rev A (you can get the revision from the circuit board;
it is nowhere else to be found, but there):

This revision had a discrete VCO and non-discrete VCF (SSM2040).
It had a better frequency responce (5Hz-27kHz) then the original
model and sounded a bit clearer with much better sounding filter.
First SRM model was produced around early '79 or so.

* Cat SRM rev B:

Same as above but with SSM2044 VCF. Sounded a bit different from both rev A and B, but not typical compare to other 2044 based machines. Some people say that knobs are sticking out a bit higher above the front panel surface on this revision.

* Cat SRM II:

Same as above, but with non-descrete VCO CEM 3340
It sounded close to the SRM rev B. This was the last and the most stable version.

There are also a lot of transitional models that have a combination
of features. During Cat's production time and shortly after Octave
Plateu offered a whole array of modifications including:

Filter Mod
Ring Modulator
External Bass Style Pedal Control
Joystick control etc.