Casio CZ/VZ Files... part of CZsynth

I have loved my CZ1000 but wanted a CZ1 for a long time. Finally I scored a "broken" one on ebay recently fot $75. Great deal even for just a controller. Why this CZ1 is making me crazy is that it does work normally except for a spurious output problem. If I strain to hear it in my headphones, I can hear the sound very faintly. So I tried loading loud patches, turning the volume up, and playing the keys hard - and sure enough the volume pops up and it sounds normal for a while. But after a while it starts to drop and then suddenly disappears. Another good way to hear it is to slide the chorus pot around, which makes enough of a pop to get things going.

Playing the synth while it is taken apart yields sound which flops around like an annoying broken cable. It seems obvious to me that this is probably an internal connection problem, but I haven't traced it yet. I started with the output board, I checked for lifted pads, cracked traces, and reflowed solder on the output jacks. Reassembled and the problem is still there. I took the whole thing apart (ugh..) and am now looking at the voice board (left PCB), it looks ok. I am beginning to suspect either the volume pot area or the flimsy interconnect cables.

Meanwhile, the CZ1 is getting a thorough bath and a checkup. I might replace some of the opamps with low-noise types, but haven't decided. This thing is such a tease!!!! It *almost* works perfectly, but then cuts out after a minute. It's like an annoying VST demo plugin. I love the sounds which I hear and would love to do some programming, but it will need to wait.

When (if?) I have solved the problem, I'll post the details here.