Demeter CompulatorVerified

From the post

Info from Demeter about the original:

"The Compulator was born after I solved an engineering problem of biasing an optical unit with only a single 9V battery. I had always loved the sound of optical compressors and designed and manufactured tube units in the pro audio market for a number of years. I wanted to make a pedal, but it took years to come up with a method to do it the right way. The result is the Compulator, winner of Guitar Player Editor's Pick Award and the only compressor that does not suck away your tone." - James

The sound of classic studio optical compression of the 60's and 70's at your feet! The first compressor pedal not to suck the life out of your tone.

Operation is fairly straightforward. There are two inputs on the front side of the unit: a 1/4" input jack on the right and a 1/4" output jack on the left with a battery-ground switch on the input jack.

There are two controls on the unit: compress and volume, plus a foot switch to bypass the effect, and an LED to indicate effect operation. On the side there is a trim pot to set the overall gain of the unit.

Compress affects the amount of gain reduction (compression) of the input signal. Turning this clock wise will give you up to 30dB of gain reduction (depending on input gain). Please note that the Compulators max gain is 26dB (see Trim Pot) so in some circumstances if your instrument is very hot you could achieve less than unity gain if you turn up the compress knob too much.

Volume increases and decreases the output volume of the Compulator. Use this for level matching between the effected and unaffected signal.

Trim pot sets the gain of the compressor's pre-amplifier. If distortion occurs turn this down until the signal is clean. The unit is set at the factory at 20dB of gain which is perfect for most instruments. If you have weaker pickups or want to push the envelope turn it up to its max gain 26dB.

Update: There was a missing cut between the top of the 619R and the 10K, so if you've been having trouble with this layout then give that a try. Layout updated below.