Vintage Simmons Drums (UK) Users Group

Hi, sorry if this is double-posted.  I'm having some mail issues:

Folks,

I just purchased an SDS-1000 and pads.  The unit was supposedly
working fine when shipped, but out of the box I am having trouble with
the kick and snare trigger inputs.  I was hoping someone here might
have an idea.

Problem:
The snare trigger input works only when I wail on the pad.  The kick
trigger does not respond at all and does not send a midi event.  The
three tom inputs work flawlessly with all combinations of pads and
cables, from light taps to heavy hitting.  The above symptoms on K & S
happen with a known good cable and pad, on all programs.

So far:
- all the voices work, since I can play them using an external MIDI
controller.
- jacks and front panel sensitivity knobs are solid and clean.  Pots
have been flushed with Cailube MCL and measure correctly with a meter.
- all socketed ICs have been re-seated
- peizo trigger signal has been traced all the way to quad op-amp
inputs for the kick and snare peak detector circuits using an
oscilloscope.

Something seems to be wrong with the trigger circuits or whatever ADC
sends the triggers to the 8051.  I don't have a schematic, and so am
unable to take it any further.

Does anyone have any ideas, and barring that, can anyone provide an
SDS-1000 schematic?
Thanks,
MikeS

****
http://www.boycrusher.com
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