- 350W, two-space rack-mount head-unit, hybrid chassis with a tube preamp and MOSFET power amp, single channel, front black control panel, two inputs (normal and bright), five knobs (v, b, m, five-position mid-range freq. selector, t), six-band graphic EQ with level slider control, ultra low switch, balance line out switch, ultra high switch, graphic EQ switch, footswitch jack, power switch, black casing, mfg. 1991-94.