VOX Valvetronix VT20X Modeling Amplifier 20 Watts; 1 x 8" Speaker Valvetronix preamp uses a vacuum tube multi-stage amplification circuit 11 realistic amp models; 13 high quality on-board effects; 33 preset programs Built-in tuner, AUX in jack, Headphones out, and USB connectivity; Optional VFS2 & VFS5 footswitches VET (Virtual Elements Technology) delivers stunning sound quality