Vintage Simmons Drums (UK) Users Group

KW wrote:
> i would go for SDS-5 or SDS-7 as a sound engine, and the sequencer SDS-6, if any other sequencer i don't know what else choose, maybe to throw in a CRT or TFT and paint it orange and call it Movement Drum III ;=)
> 
> cheers....
>  
>

It wouldn't be difficult.  The SDS-7 uses a couple of unusual chips, and 
of course the hybrid modules on each board.  I tried reading the service 
manual on www.simmons.synth.net but it's scanned at way too low a 
resolution - labels on IC pins and board connections are maybe 3 pixels 
high at best!

Getting the Curtis VCO and VCF chips would be tricky, to say the least. 
  However, there are a lot of DIY synth websites out there with circuit 
diagrams for VCOs and VCFs made from discrete components and 
easily-available op-amps, so this need not be a problem.  I haven't 
really worked out what the hybrid does - by the looks of things it's a 
kind of multi-channel sample-and-hold.

Gordon.