I love my 1979 MXR Micro Amp pedal. No light. No True Bypass. No power adaptor socket. But it sounds great and invariably makes almost any amp sounds better. See pic below... Anyway, I have found that my Mooer Yellow Comp is not only a good sounding optical compressor and a subtle yet effective EQ / enhancer but also it's not bad at reproducing the tone of a booster pedal such as the MXR or the also very good Xotic EP booster. The Mooer does not have as much uncompressed gain as the MXR but still, it does the job quite nicely. The MXR sounds slightly rounder and clearer and there's more gain available but the Mooer with the Comp knob at zero, the level maxed and the EQ just over noon, sounds very similar to the MXR set at noon. Today I spent some time with both comparing the tone with both chords and melody lines. Short video showing that I'm not making this up. Old MXR booster set at 11 o'clock vs Mooer Yellow Comp pedal set as a clean, uncompressed. First no pedal then the MXR vs the Mooer a few times and finally back to straight, bypassed signal. Guitar: vintage strat type bridge and middle pickups. Amp: Harley Benton GA5 valve combo. 8" ceramic speaker. What a nice surprise!! Anybody use this yellow pedal in this way??