Just finished wiring this up after waiting a bit for the 13700 chip. I'm a bit of a comp affectionado, so it was nice to try out a new "easy" design. I hope it's okay to post my thoughts here:
It sounds beautiful as a boost on certain milder compression settings.
In the stock setting, the most extreme compression settings lost some highs. The treble boost mod cures this, but I can see how players who use picks (I'm strictly fingers) might find this desirable.
The bass response is a little smeared at the most extreme comp settings.
How does the compression "feel"?:
The lowest ratio resistance provides no available boost, but it is extremely even limiting and feels very natural. The highs are fairly attenuated, so, again, I found the treble mod to be a perfect cure for my complaints here.
The next 100K of resistance was all very usable in every "normal" testing situation I messed with - it sounded right and reacted right at all areas of the sweep, but with varying levels of overall compression, high end, and boost available.
The compression is very natural compared to a Dynacomp (despite certain people's assumptions elsewhere), though I must admit that the range of the ratio knob for the purposes of compression
can be fairly limited with any given guitar. Using my tele w/ broadcasters, anything above 250K was virtually indistinguishable from the settings below it except that I got more pumping like a mis-biased Orange Squeezer, and the release was a little too long when switching between slow soft notes and fast runs (meaning that the fast runs would keep a quiet part immediately following from sounding correctly); I tried a strat and found that the 100KA pot would suffice (but the low-input pickups did like the very top of the comp knob)! I don't have a super high output guitar to test, so I ran a boost in front and I could see how, say, active pickups would like to have the 1M pot. It still had some transients and didn't distort (which is very nice), but there were some noise floor issues.
I built it almost stock - I used a 500KA pot for the ratio because that was more than sufficient with every guitar I own and gave me the most usable sweep. A 250KA would have been ideal for my purposes, but I didn't have one. After testing the attack mod (which I didn't like -- but then, I don't typically like that mod on anything) and the release mod (which I did like for more transparency, but the release is already very short), the treble mod was the only one I really found essential, as it cures the only problem I had with the highest compression setting.
This walks the line between hard "effect" compressor boxes like the Orange Squeezer and Dynacomp and really transparent comps like the Flatline. It would certainly please people who want more squish than the optical comps but don't necessarily want to know if it's working.
I'd recommend this project to people looking for another "effect" comp, but maybe not people looking for absolute transparency.
Is is a "better compressor"? I think it's certainly better than the Ross for my tastes. I've never really liked the Ross.
One last thought:
It's tough on perf, and the etch is complicated with a lot of jumpers. Maybe a group buy for double-side fabbed boards is in order?
Anyway, it's going in a pretty green box as soon as I get to the drill press tomorrow.