This is the best of the best pedals that can make you sound like a big monster even in a small amp from 10' 12' 15' and even compressors in bass cabinets. That sounds even in a solid state amplifier, but I recommend valves amps with other valves (see at bottom of this) and so on to get a more precise sound after tweaking, it's warm and very loud even without compression. Emulation is very well done and efficient. All frequencies with 6,7,8 strings are magnified !!!! I've tested it with a mandolin in an Ampeg Valve Head and 8x10" If you put on the compression, be careful your ears will quickly heart if your are very sensitive. One chanel , killer sound to soft distorsion to metal ones. Be careful voltage is 22 volts it is high one. You can change the "EHX 12AX7" with "JJ NN003 ECC83S" or "TAD12AT7" , I tested the JJ ones and did not remark a great difference but I prefer the Sovtek EHX ones they seem to be clearest and brightest , this is my opinion, not yours, experiment. These are preamps valves and not amplification one don't be confused !!!