So I made a couple of John Hollis Flatline compressors a few years back in a really badly designed box as I was way too excited to try them outto bother building them properly. It was designed for use with a bass guitar but I recently discovered they sound awesome when used for drum compression and pump like absolute hell! So I thought it was about time I re-boxed them and made a demo.
The first 2 bars show the drum loop on my dusty old DJXII played in bypass mode on the Flatline with it being switched on just afterwards. The difference is not subtle I think you'll agree and makes for massive techno drum sounds. The Volca Bass and Monoton Delay is also running through it and it does a great job of keeping its resonance in check, then lifts the noise floor loads at the end!
All in all a great bit of kit if you want an opto-compressor with very few controls and don't mind a bit of soldering. I used the following links I think: