Vintage Simmons Drums (UK) Users Group

Hi everyone, hopefully someone can help me.

I've recently purchased 3 SDS1 drum pads...and they all seem to have the same issue.

I'm powering them off batteries, not psu at this moment in time, as I don't have a psu for them.

When I hit the pad they make mad arcade type 8 bit noises, even when the eprom isn't plugged in. and when the eprom chips are in place you can hardly hear them due to the other noise being generated.

All three units have the same problem...

does anyone have any idea what could be causing this please? I don't think its an eprom issue due to the fact the noise is generated when hitting the pad, with or without the chip in place.

Thanks in advance for your help

Phil