- preamp only, rack-mount head, solid-state chassis, black control panel, nine knobs, black casing, 5.25 lbs., mfg. 1991-2001.

- 400W, power amp only, single channel, front black control panel, single input, single volume knob, power amp meter, rear panel: power switch, two Speakon speaker jacks, pass-through jack, Neutrik combo input jack, black casing with chrome rails, 8.5 in. wide, 1.75 in. tall, 9.75 in. deep, 3 lbs., mfg. 2010-disc.

- preamp only, rack mount head-unit, blue or chrome control panel, two inputs, eight black knobs, four LED lights, single rack-mount space, 7 lbs., mfg. 1993-2002.

- preamp only, rack mount head-unit, silver and black control panel, two inputs, eight black knobs, four LED lights, single rack-mount space, 10 lbs., mfg. 2002-06.

- preamp only, two-space rack-mount bass head, hybrid chassis with 2 X 12AX7 preamp tubes, single channel, front light blue anodized aluminum control panel with two chrome handles, 16 black knobs, front panel controls: two selectable inputs, mute switch, Bass Intensifier on/off switch, level knob, and cutoff knob, Compression on/off switch, threshold, ratio, comp position, attack, and release knobs, Boost on/off switch with level/comp blend knob, Pad on/off switch, gain knob, Aural Enhancer knob, five EQ knobs (b, semi-parametric EQ with l, m, h, and t), effects blend, MV, power switch, rear panel: XLR and 1/4 in. preamp out with ground lift switch, Tube DI with XLR and 1/4 in. out and ground lift switch, phase switch, and three-way direct compressor output switch, effects loop, footswitch jack, tuner out jack, aux. input jack, black casing, four-button footswitch (controls for Bass Intensifier, EQ Bypass, Effects Loop, and Boost) included, 19 in. wide, 3.5 in. tall, 11.125 in. deep, 13 lbs., mfg. summer 2008-disc.

- 750W power amp only, rack mount head-unit, silver and black control panel, single volume knob, four LED lights, silver casing, 32 lbs., disc.

- 800W mono, 350W per channel stereo, power amp only, rack-mount head, solid-state chassis, two channels, front black control panel, two volume controls, black casing, mfg. 1991-2001.