Controlled Voltage / audio reactivity

Does anyone have good tutorials on incorperating some audio reactivity into bends? What all has worked for you guys.

Pushkar brand has an amazing tutorial here for bending and shortly brushes on his cv setup, just looking if there is anything more out there


I think i should include what im looking to do also. Id like to include audio reactivity from a composite/compontent audio cord. However i plan on doing some more live stuff and one of the guys i work with has controlled voltage equipment so i want to figure out how to add that to my visual stuff

im sure theres more advice out there but just a couple of thoughts:

  • if you want something to be reactive to audio (not just cv) a keyword to look up would be envelope follower - this is a circuit that will convert audio to cv (more or less)

  • if you have a pot or slider that is acting as an voltage divider (this usually looks like all three legs are connected - the two ends maybe connected to power and ground through resistors with middle leg sending out the variable voltage) then you can inject your cv straight onto this (provided theres some over/under protection…)


  • if you have a pot or slider or bend-point acting under variable resistance (might look like end and middle legs connected with 3rd one not being used) then a way to get this to be cv controllable would be using a vactrol - basically an led plus ldr together in heatshrink → your cv sets the brightness of the led and this sets the resistance of the ldr - resistors on either side help calibrate to the range you want


Thank you ill check this out!

This thread may be useful if you haven’t seen it already:


thank you!

So i ended up getting the stuff for a vactrol, however i am running into the issue of not getting enough voltage to light the led. I had gotten a mini jack socket and an adapter for 6.5mm to 3.5mm and used a 3.5mm aux cable to carry the audio to it. I am unable to get the leds to light up. A friend of mine suggested an op amp but im not sure how to use those. Do you have any suggestions?

Yes I think your friend is correct. Can you read schematics? There’s envelope followers in several guitar pedal designs - one you could check out is called the Clarinot by Mid-Fi Electronics. It uses an integrated circuit (LM386) to light up the LED. The same IC is in this circuit too, which uses very few parts. Could be a fun thing to try on a breadboard.


Thank you! Ill try this out

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