Thanks for the link. I will recap the psu and mainboard soon and also change all voltage regulators. Meanwhile I encountered more problems. When the SD-1 is running for some time, it randomly reboots itself multiple times, sometimes with error messages 137 and 144 in-between. Reference voltage value...

Thanks for your reply. On mine it doesn't seem to come from the fx section. Yesterday I plugged the SD-1 into the line input of my audio interface instead of the guitar amp I was using before, and there weren't any problems. So I think the crackle is perhaps caused by wrong input impedance (I'm so d...

Hello, I just bought an Ensoniq SD-1 or to be precise a VFX-SD with a SD-1 mainboard (changed by customer service in the 90s). At first it seemed it works well, but then I noticed crackling noises, mostly when playing Bass patches. The crackle sounds like dust on a vinyl record. Sometimes it isn't t...