OVERDRIVE CIRCUIT: Explore bass tones from classic gritty growl to slap-worthy modern punch with the newly-developed overdrive circuit and switchable contour controls. LIGHTWEIGHT YET POWERFUL: A beefy 200 watt class D power amp and ported speaker enclosure, pumps volume and deep bass response but keeps this amp very light in weight - only 34.5 pounds! HEADPHONE OUTPUT JACK & AUXILIARY INPUT: For convenient private practice at any time that won't bring the house down on anyone else within earshot, this amp features a headphone output jack. Jam along with your favorite tracks by simply plugging your MP3 player into the 1/8" Auxiliary input jack and instantly become part of the band.