I'm getting close with my Chroma Polaris restoration, but I have a question. How abrupt should the decay on the Volume Envelope be? I feel like I never hear a smooth decay to zero, it is like it drops off abruptly, which seems unusual, at least compared to other synths I've ever owned, but I didn't know if it's a feature...
One thought I had was to probe the opamp output for example Z503 pin 7, disable the other voices, and watch an envelope decay waveform at different settings. But it seems unusual to me that the voices would all cut off similarly. I should mention that it properly tunes five of the six voices, I'm waiting for a CEM3372/74 to repair the 6th channel. So that suggests to me that the DAC chain works properly.
I also should probably reload some preset voices, maybe I'm just missing something with the patch programming.