The Yellow Comp is a great little mini pedal which rounds up the output signal nicely, eliminating undesirable frequencies and keeping the good ones, with some versatility of use, at a very friendly, budget price!.. and doing all that rather quietly, which is an important issue that kept me from opting for a slightly more expensive, dynamic compressor, such as the famous MXR Dynacomp, or the BOSS CS-3, as dynamic compressors are supposed to be more noisy, but yet might be more authentic in sound?
Let me warn you though, about this review, that pedals are NOT my specialty, I am mostly a plug and play guitarist, trying to use effects "minimally", save for a Wah-wah pedal, a little chorus at times, a rare delay, and some reverb.. But... I am indeed a specialist of TONE, and timber, and hearing and achieving "the" holy tone, which can be different, on different moments, at different times, for different people, but mostly it (for me) resembles the sweet music coming from a top notch old lamp radio (transmitting probably a super nice guitar tone through a vintage Fender Amp?)
And, yes, I did achieve some real sweet tones through the Yellow Comp, placed in between a Blues Junior Limited Edition and a Gibson SG. The VOLUME and EQ knobs on the Yellow Comp are great to have to be able to "keep your own tone". I normally have my Blues Junior dialed in on my usual set up, and with the Yelllow Comp's volume button (which controls the gain coming out of the compressor really), and the EQ dial, this compressor allows me to keep the output tone close to my normal tone while making the general sound nicer through compression.
So in this way, it is a great little "cleaner", just by itself, for clean tones, between an amp and a guitar. However, with the gain turned up on the compressor (through the volume dial), and equalized to your liking with the EQ, it becomes a compressor, plus a sort of an overdrive/distortion, or a booster, added on! It sounded especially magnificent with the amp dialed to make some real tube gain, plus the additional gain from the Yellow Comp with its volume dial set high.
With this sort of "overdrive" setting, plus an octave pedal, and a Crybaby, before the compressor, we were able to reach some incredibly far out dirty tones going on Hendrix-ian territories from the Blues Junior.
Coming back to clean settings, with the octave and Wahwah pedals still before the compressor, Yellow Comp cleaned up beautifully, making the tone round, and bright, and managed to keep all the potentially disturbing "high-pitch-grit-dirt", whatever you wanna call it, arising from the Wahwah, and the Octave pedal, OUT OF THE MIX!
Overall, Yellow Comp does the job, and it does it quietly, so I reckon that it is a good return on just a few bucks invested, and that, even for a tone freak like myself! It probably will not give that David Gilmore sustain per se, but there are Dyna Comps for that.. This compressor, on the other hand, cleans up nicely, by itself, or after other effects as well. It sure will remain a part of my set up, at the very end of the chain, just before the amp, until further developments!