Ross compresso bias adjustment

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blaise
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Post by blaise »

Hi,
I built the Ross compressor clone from https://tagboardeffects.blogspot.com/20 ... essor.html. I'd swear I had found a youtube video explaining how to adjust the bias resistor, but I can't put my hands on it. Does anybody know how should the bias be adjusted? I think remember it involved making sure that voltage on two legs of the IC were equal, but I don't remember which ones.

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mauman
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Post by mauman »

Welcome to the forum!

If you're talking about the 2k trimmer, it allowed adjustments for any imbalance between the inverting and non-inverting inputs on the early versions of the CA3080. Pins 2 & 3 on your IC. But current versions of the 3080 don't need that, just set the trimmer at 50% (1k/1k) and it should be fine. Other versions of this layout just substitute two 1k resistors for the 2k pot.

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blaise
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Post by blaise »

Got it, thanks.
Out of curiosity, I’ll still check the voltage on pins 2 and 3 of the IC

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