As the name implies, the CompROSSor is Analogman's recreation of the classic Ross Compressor, but with a few upgrades.
Mike had been playing in a band for a few years, and noticed that SOME pedals on his board would not drive a load well, they would get dark and dull, due to a bad (high) output impedance. This is easily tested by running pedals into something like a low impedance volume pedal, with a switchable buffer between them. The original Ross, Dynacomp, and all the other Ross clones have this problem - they really need a buffer after them to sound good.
Also these pedals don't have a very loud output, especially when you hit them hard, for example with humbuckers or a boosted signal. One other problem all these pedals have is phase reversal - they flip the phase of your signal when you turn them ON. This may not be a problem for most people, but if you split your signal and combine it, or run into two amps, the out of phase signals will cancel and you will get a VERY thin sound. Also, for use as a clean boost, there was too much compression even with the SUSTAIN pot all the way down.
Analogman reduced the minimum compression amount, without changing the maximum amount. Now the pedal is more usable as a clean boost, and also sounds great left on all the time as a tone sweetener/buffer. It's great stacked into dirt pedals, chorus, vibes, etc now.
With the Rev5 circuit, Analogman added a Mix control. Mixing in dry gives you more attack on the note, which is compressed away normally, if you want to hear that. When set at full dry, the pedal becomes a clean boost/buffer pedal and makes pedals after it sound really great, with more presence.
The "Ryck" toggle switch allows you to engage a Rickenbacker-style circuit to bring out some more high end and tame the muddiness usually inherent in the Dyna/Ross compressor circuit. Looking at the Rickenbacker schematic, it's about the same as the Dynacomp or Ross except it allows more treble for that jingle-jangle sound. Analogman decided to offer this with a three-way switch so you can get just the amount of treble you want. One position is the normal Dynacomp/Ross value for about the same tone as when the pedal is OFF, and low noise. The second position adds a bit more treble and just a touch of noise - this may be great to use all the time with a darker guitar like a Les Paul. The third position is twice as bright, close to the Rickenbacker setting, for a sound that really pops, with a bit of noise that you probably won't even notice.
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