i already had one of these on my pedalboard hooked to a Mesa DR, with heavy distortion going into the red channel.. and oh boy it could get loud. this little pedal took care of all of that, and did not eat away from my sustain while doing it. very slightly.. def ntg i cant live with during soloing.. silent as a sleeping baby when its on, i play a lot of riff driven songs and palm mutes and cut offs are clearly mute and silent.. not a hum.. i bot this second unit for my JCM800 setup.. took a bit more -db to get rid of the noise but did the job nonetheless.. when its on the amp is completely silent. one note, for what its worth, the unit works better going into the amp then it does going thru the fx loop. takes less db to shut off the noise.. i put mine after all the noisy pedals, but before delay and reverbs.... on the Mesa setup i also have a Zuul going thru the fx loop.. yes, it takes both of them to tame the pedal/amp combination i have going on.. on the JCM, all i need is one.. ive been a long fan of isp products, they do one thing and they do it right.. everyset up i create will have one of these on it !!!