The HB (Hybrid Bass) series is a TRUE hybrid
bass amplifier designed for all players including
the seasoned professional. “Hybrid” refers to this
amps totally unique, all-tube, point-wired preamp
section, and completely transparent power stage 
which uses six of Sanken's best transistors.

Many amps on the market which boast a "tube preamp" simply put a 12AX7 tube at the front of the preamp circuit, and run that one tube at very low voltage. While that may slightly color the sound, it will not deliver the tonal qualities of a true tube amplifier.  The HB400 Possum Stomper derives ALL of the voltage gain from the preamp using high-quality Tung-Sol 6SL7 and EL84 vacuum tubes on a full 250 volt supply. The final tube stage actually runs at significant power level. The end result is that you get all the warm, rich tone of an all-tube amp, but much lighter, less expensive, and with no compromise on sound. It’s that 70’s VINTAGE SOUND from the heyday of the best tube bass amps!

The HB400 Bass Head provides 400 Watts RMS into a 4 ohm cabinet (available separately).

The “Style” control allows adjustment of the harmonic content of the sound between odd or even, essentially allowing control between a push-pull sound (PP) and a single-ended sound (SE). The main audible effect is the control of second harmonic content.

Overload protection is standard. Soft-start circuitry protects against inrush current and prevents fuse blowing on cold starts. A fault indication light indicates an overheating condition or a problem with the soft-start circuit. Line-out is provided for a DI of +4 dBu.