A more complex 6 voice dual vco/voice subtractive analog synth similar in many ways to other CS series. But improved in the memory department having storage for 30 patches. And a handy dandy card reader!
I've never worked on one. But it shares same chips for vco and vcf as other CS series.
I had a most peculiar manifestation shown in a video I did on CS5. The cutoff control would just cease to impact a highly filtered sound at the Ab second from top and below or like that. It would change a note during warmup. Turned out the VCF chip was the issue!
I believe I should have any electronic part or keys for these save exact transformer, etc. Ask if you have need.
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