i used the one in my sfbm until it started getting fritzy. you could here the tube switching on and off. soooo, for the price of getting my amp fixed, i now have a tuna melt, a rogue, and that ggg e.a. tremolo with the preamp. i go back and forth between the e.a. and the rogue. the tuna stays home usually, or gets used for vocals when we're feeling trippy. plus, it's one less wire running back to my amp. (the one for my footswitch) and yes, i use it. i play in a garage band with alot of surfy type guitar sounds.