Mozztronics CO-2 Opto-Comp Optical Compressor

We’ve had a blast reviewing and demoing this round of pedals from our friends down at Mozztronics in Australia, and we’ve got the last one from this bunch for you today. Many revered studio compressors are old valve (vacuum tube) units used an optical element for the compression. These compressors were easy to dial in, and no matter what setting you put the controls at, they never sounded bad…interesting, but never bad. Mozztronics set themselves the task of taking the essence of these old vacuum tube compressors, and coming up with a solid state circuit that captured how these old compressors sounded. Using an optical element for the compression, the CO-2 Opto-Comp Optical Compressor had to be useful for both guitar and bass, and had to be different from what is already on the market…

As far as the controls go, Gain is the make up gain so you can adjust for the same volume from bypass to effect active, Ratio controls the amount of compression from barely on to super squishy, while THReshold adjusts the point at which the compressor starts to operate. The ATTack knob controls the speed at which the compression starts to operate, so as to let through initial dynamics & keep sparkle in the sound (min attack time is anti clockwise), and RELease controls the speed at which the compression stops operating (minimum release time is anti-clockwise).

But that’s not all…the CO-2 Opto-Comp Optical Compressor also features a Range switch selects the frequency range the compressor sensing uses for its operation. Up is full range. Try both positions to see which works best for your playing and your instrument. Finally, DYNamics uses an old studio trick of “parallel compression”, by mixing in a little of the raw uncompressed signal to add back some dynamics, you still get the compression, but keep expression and feeling. Mozztronics also added some tricky internal circuits around the release control, calling it “interactive release” – while you can set the release with the potentiometer, an internal added release works in parallel and varies depending on the input signal.

What an excellent-sounding compressor, and what a fun lineup for pedals in general. Not only are they really well-made and stand out in a crowd, they sound incredible, which is the main point of an effect. You can see and hear the time and effort that have gone into each one, and we applaud Mozztronics on their dedication to bringing these wonderful circuits to life. If you haven’t seen the rest of our reviews (wHo WATT, Tube Driver, ORANG-e and Baconizer), be sure to check those out. And to find more information on these and the entire Mozztronics family of effects, be sure to visit their website ASAP. Cheers!