[sdiy] VC distortion?

[Aaron Lanterman]

>> variable resistors.  I imagine you could build a voltage controlled pot
>> using two vactrols, one with an inverted level sent to an LED - has anyone

> about doing too. My thought had been to use a variable gain stage based on a 
> transconductance op-amp (Say a LM13700) as the 'op-amp' part of a basic 
> circuit like the Rat Distortion or the Tube Screamer.

In terms of emulating a pot, that's tricky. I had students play with this 
last Spring with vactrols and OTAs - never quite got working 
satisfactorily, so I wound up suggesting that they take a step back and 
figure out what the circuit was trying to do and design something new to 
accomplish the same task that was more single vactrol or single OTA 
friendly.

I'd recommend, if feasible, looking at the circuit and seeing what it's 
doing at a functional level, instead of thinking about brute-force 
replacing a pot.

- Aaron

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Dr. Aaron Lanterman, Asst. Prof.
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