Schematics / Noise Gate And Compressor-Sqeeze Box
Noise Gate and Compressor (Sqeeze Box) by Seb Francis ,as part of his Box-O-Trix ,more details and the rest of the schematics on his page http://burnit.co.uk/sdiy/index.php?page=boxotrix from there the brief description on the whole Box-O-Trix :
This is a modular compressor / limiter / distortion / gate unit. It was born out of my desire to have many different flavours of distortion available in a compact format. I'd had enough of my studio space being taken up by old mixing desks, battery powered guitar pedals, etc. just because I liked the sound of overdriving them. So I set about breadboarding many different designs until I found a set that gave me a good cross section of wonderful sounding distortions.
The next thing I wanted to add was a compressor or two - very useful to put before distortion in the effects chain, but I also wanted a super-flexible high fidelity unit to use stand alone as well. One nice feature is that the minimum attack rate goes so low that it makes it possible to introduce lots of self-AM distortion for bass sounds (can be a great effect, similar to a ring modulator). If the release rate is set above minimum then you don't get this effect, but instead you have an ultra fast peak limiter.