Ampeg SVT-3PRO Bass Head, 450 watts into 4 ohms and 275 watts into 8 ohms, tube preamp with 3 x 12AX7, driver tubes 1 x 12AX7 and 1 x 12AU7, 3-band EQ and graphic 9-band EQ, mid-tone-control with 5 positions, ultra low und high boost, adjustable DI-out with ground lift switch, effect loop, preamp out and power amp in, Dimensions WHD: 48,26 cm (19") x 8,89 cm (2 U) x 39,37 cm