Help! Ensoniq MR Rack electronics problem

[Karma1]

I've got an Ensoniq MR Rack synth module that has a strange and very intermittent problem. While playing it, it will suddenly give off this very loud sustained high pitched squeal, that sounds a bit like a feedback spike or digital clipping, but is probably neither of those. At first I thought it might be the monitors overloading from too much gain at the mixing board, but bringing the volume down on the faders or the module doesn't help. The only way to stop it is to turn the module off, then when you turn it back on, it is fine - until the next time it happens, which could be an hour or a few minutes.

 

I've got about 10 other synths in my rig, and none of them do anything like this, so it's not the monitoring system. If anyone has any idea about what is creating the problem with the Ensoniq, I'd greatly appreciate hearing about it.

 

Thanks!