it's already nearly two years ago, when I bought my first pedal kit and made my first steps in building my own effects.
Since I have not so much time to practice i'm still a noob but i'd like to upload a circuit I've been working on.
I wanted to build my own noisegate and on my way I stumbled across some circuits to get started, but none of them really satisfied me completely.
Most of them suffer on an unnatural decay behaviour at higher release times.
I now built one by my own but borrowed nearly all the parts from other circuits.
This one is based on a cheap optocoupler IC named PC817 for the gating itself. I don't know, why noone ever uses this thing in a noisegate circuit (at least I couldn't find one on the internet), but for me it works quite well.
I don't use the signal envelope itself for gating the noise, instead I built a schmitt-trigger upon it, fed with with a variable reference voltage to set the threshold of the gate.
After that, i added a simple AR envelope based on two pots, 2 diodes and a 22u cap to set attack and release.
Until now, I only built this one on a breadboard, but it already works fine as far as I can say.
Maybe someone want's to give this thing a chance and rebuild it. I'd appreciate your opinions and ideas for modifications and enhancements.
Edit:
- Adjusted R3 and R4 to improve threshold sensitivity
- Added a pull-down resistor after output cap (R12)
- Adjusted resistor values for R5, R7, R8 and R9 to improve schmitt-trigger hyteresis and threshold sensitivity
Here's the schematic (updated):