Crumar DS2

Got this machine in a very good cosmetic condition, all buttons still on, no scratches. Unfortunately ( and quite common to this machine) it did not make any sound.

Crumar DS2

Crumar DS2

Lot of things to debug, i cannot even remember all of it anymore, but I remember that almost all OTA’s from the filter and LFO delay’s were bad. Maybe they came from a bad batch.
Also a lot of the TTL circuits had failed, mostly from the oscillators and keyboard decoding. Fortunately, all of the IC’s are on sockets, so they are easyly exchangable.
Watch out for bad contacts too, there’s such a lot to go wrong here…
But the sound is incomparable, with this pseudo-digital waveform creation, which is more like an analog oscillator made with TTL components to me…
Filter nice too, has something like a sweet-spot. And is comparable of the one used in the earlier Octave_Cat’s.

I added a Polyphonic midification to it, but it was a tedious job, using many Cmos switches and a lot of cabling. But it works really well!

Custom build polyphonic midification.

Custom build polyphonic midification.

Loads of Cmos switches for Keyboard emulation, switches are driven by a 64 Output Doepfer Midi-digital out converter.

Another shot of the unit:

Totally wired!

Totally wired!




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