So I set out to build this since it was the easiest thing to build (parts count) that contained a ca3080 that I could use to test the chips. I did get the tremolo section to work but the ring modulation section is just the dry signal plus the carrier signal bleeding through. Question is, if the tremolo is working does that mean that the ca3080 chip is working correctly? I have zero knowledge of OTAs so I'm really in the dark.