The legendary tone and portability of the all-tube Ampeg Portaflex amplifiers is faithfully reproduced in the PF-20T. This all-tube Portaflex head provides a harmonically rich and studio-worthy 20 watts of pure Ampeg tone to satisfy the most discerning bass player. Featuring simple user-adjustable bias adjustment for easy tube replacement and pre-amp and transformer balanced direct outs for maximum versatility. Plus, no speaker load is required for silent recording or even use as a dedicated tube DI. Pair it with the PF-112HLF for the ultimate compact all-tube bass rig. RMS power output: 20W @ 4 or 8 ohm; Preamp: All-tube [2] x 12AX7; Power amp: All-tube [2] x 6V6; Tone controls: Bass, Mid, Treble ; Input gain control; Preamp balanced line out: Pre/Post EQ, Ground lift; Transformer balanced line out: Ground lift, User adjustable bias control; Dimensions (H x W x D inches): 185 x 330 x 264 mm; Weight: 6.9 kg.