Simmons SDS7 Digital Analog Drum System (1983) / hybrid analog drum synthesizer & 8 bit PCM rompler

video upload by ohm_studi_ohm

"in the first part of the video I run a simple pattern on a Roland TR8s that triggers the SDS7, and I demo a few kits I programmed.

On the second part I play live drums over a simple kick / hat / clap pattern and review the same drum kits and finally I play the sounds alone.

I'm no drummer so forgive my playing. These last parts are mainly intended as to demo how the SDS7 handles dynamics.

recorded through a Tapco 4400A reverb. No other fx or editing.

The Simmons SDS7 combines analog drum synthetis and 8 bits sample playing.
Each voice lets you blend 1x VCO (CEM3340), 1x 8 bit sample on eprom (like many 80s drum machines ie LinnDrum, Oberheim DMX, Sequential Circuits DrumTraks etc), 1x noise generator and 1x click generator.
Then those 4 sources pass through a nice 24db resonant filter (CEM3372), which doubles as VCA. There is a simple cutoff enveloppe and vca release parameter, and both the VCO and sample have a simple pitch enveloppe as long as a lfo to pitch modulation depth. The lfo speed can go to audio range thus enabling FM tone, great for bells and fx.
All voices card pcbs are the same except for the eprom containing the sample and this can be replaced with other sound (the clap on this unit is a CR8000 clap i programmed for instance).
There is however a second type of card, hi hats card, that differs from the basic one with some more components that let the voice be controlled by the hi hat pedal (decay of the sound mainly). It's easy to modify a regular card to a hi hat card, and to build a simple adapter in order to use a momentary switch pedal to act as the hi hat pedal. You can even use a progressive pedal to mimic the opening of the pedal, this is what I'm using and doing on the video (off screen). Info on how to achieve this are available on this site (thanks to the author for sharing this ): https://www.drummachines.de/beatboxer... If you're interested in these units tons of info are available on that site (again thanks to the author for the great job): https://snw.lonningdal.no/sds7.php"