Archive of the former Yahoo!Groups mailing list: Vintage Simmons Drums (UK) Users Group

Don't know anything about the SDS-9, but did you ever do a factory reset? I've often found it to cure odd behavior on electronics.

Also try to figure out functionality of IC19 mux. I've only had a short glimpse on the schematic so not completly sure if it's actually responsible for MIDI triggers by shorting the channel to ground.

-hans