Octave/Plateau CAT SRM Synthesizer SN B3933

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Uploaded on Mar 31, 2020

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"A genuine, working CAT SRM, and I'm the original owner, having purchased it on April 18th, 1980. Yup, exactly 40 years ago.

This unit was never abused, but it definitely was used in live performances. That explains the scuffed side panels; I didn't have a road case for it. The control surface and keys are nice, but yeah, that wood could use a refinishing. Funny... I just noticed that an ebayer in the UK sells new side panels. Good for you, fella! Come to think of it, maybe you could just switch the panels left-to-right so that the "good" wood is now outside? Hmm...

To hear and see this synth in action, follow this YouTube link: [video embedded above]

My keyboard setup back in the day included a Rhodes 73 Stage, Farfisa Syntorchestra, Clavinet C, and this CAT. Very, very analog. the CAT was pretty much a solo instrument, although it did play the occasional bass line.

All functions work, although after all these years a little contact cleaner wouldn't hurt. Once in a while you get a "drift" when releasing a key (each note is generated when a key-press puts a very thin reed into contact with two long rods; all contacts are exposed and easily accessed, so it's all right there when you remove the bottom cover). I've only noticed this issue very occasionally on the top C key and nowhere else (it doesn't occur in the video either). I probably should've cleaned those little reeds and been done with it, but I'd probably pull some dumb move and screw something up.

The sliders and knobs move and operate properly, but the pitch bender slider gets iffy when pushed upward. I can't remember whether I wore it out or damaged it, but it probably needs replacing--or at least servicing--to get audio during its full upward travel. I had plans to locate a new slider down the road, and even stuck a piece of tape on one of the wood sides with a drawing of the slider as a reminder of what I needed. But I never followed through. The slider pulls the CAT down its full octave without issue (and will bring it up a full octave with a dropout on the way), so it's obviously just that slider itself.

Other quirks: when switching from Mono to Poly, there's a slight pitch change which probably shouldn't happen. I don't know if that's a function of the internal tuner pots, which are accessed via pop-out plugs on the control surface. I even typed up a little guide--yes, with a typewriter--and stuck it on one of the wood sides to remind me where those pots were located. One of the photos shows the typed paper, in which I noted the Mono/Poly pitch change way back in 1980! Also in that note is something I noticed while making the video: all of the Fc (Filter) slider's control range happens in maybe half the slider's travel. The rest of the travel just goes "out of bounds" and doesn't do anything. So while the note says "touchy", that doesn't mean "glitchy"… it means a little bit of movement makes a lot of difference. That typed note also refers to Oscillator 2's Sub-Octave slider dropping out below half volume; I didn't notice that when making the video (you'll see and hear when each Sub-Octave and Waveform slider is pulled up and down individually).

I think the video shows pretty much everything else I can think of: the various Waveform generators, Sub-Octave sliders, LFO actions, ADSR controls, all that stuff. Oh, and on the extreme right is a Noise slider, which just adds white noise to the notes being played. It's not demonstrated in the video but it works.

I've not tested any of the jacks on the rear panel, except the High and Low Outputs.

I've seen pictures of other CAT SRM's with different colored knobs, which may have been running changes at the factory. All sliders on this model have the original brushed-aluminum knobs, and the cream-colored-with-black-inserts dials are original too.

The original owner's manual comes with this unit. Rather than printing an SRM-specific manual, Octave/Plateau supplied CAT SRM owners with a standard CAT manual, with SRM supplements stuck inside. Also in the manual are one-page ads for the Catstick controller, the Kitten synth, etc. An assembly line inspection tag and warranty card are there too.

Sorry shipping is a little steep, but I'm going to have to make sure this unit is packaged really well. It's a tough old girl (hey, it still works after 40 years) but shipping damage is not an option on such a cool instrument.

Thanks for looking... stay healthy!"