electrical crosstalk?

[jdigdug]

Sometimes when I hit my snare pad, the ride cymbal will also trigger. I thought this was due to mechanical crosstalk, but even with the ride unplugged I still get the erroneous extra trigger out of the megadrum.
I also often get hi-hat pad triggers when hitting the kick drum as well.

Any ideas on likely culprit for a problem like this? I'm using firmware from Nov. 2009, and synthex's kit 3.1, if that's relevant.

[dmitri]

Are you sure that resistors on the ADC inputs are in fact 4k7 and not more?

[jdigdug]

I tested the resistors that came with the kit to ensure that I was using the correct ones. I could barely remember how to read the color bands.

Should I test for connectivity between various input jacks to see if there's a short between them or something? I find it odd that I'm getting consistent false triggers on these inputs but not others like AUX7 or TOM3 or whatever.

I'll get my multimeter out and see if I can measure anything suspicious.

[jdigdug]

I learned nothing with the multimeter so far.

I've found that unplugging the TRS cable from the back of the megadrum will stop the false ride triggers when hitting the snare. Having a cable plugged in, either with or without the ride pad attached at the other end, will allow the false ride triggers.

I have the megadrum mounted in a metal box, I'm wondering if I've accidentally provided a connection through the enclosure. I'm going to take it all apart and see if I can reproduce without the enclosure.

[jdigdug]

Given Dmitri's response above and noticing that the FAQ even lists this issue as a component issue about clamping voltages on inputs, I did some experimentation. It appears that my drum pads (piezos) may just be too hot (output voltage is too high for the circuit as designed). I only get the crosstalk when I hit the pad at full velocity, so I might need to lower the voltage on my piezos, at least for the kick and the snare.

[dmitri]

Is it HC4851s that you use as MUXers ? They should not exhibit this electrical crosstalk.