Here is a very cool amp for the player that likes to experiment with their tone, the THD BiValve-30. This amp head is in very good pre-owned condition and allows the player to switch the dual output tubes to many different classic valves without the need for re-biasing or matching!

There are light signs of use on this amp including some small marks but overall it is sounding great. This unit is currently equipped with 6L6 power tubes and 12ax7 preamp tubes.

The BiValve-30 is a Single-Ended Class-A amplifier head with dual output tubes that can be switched at will among many octal-based power tubes, including 6L6, EL-34, 6550, 6CA7. 6V6, 6K6, KT-90, KT-88, KT-77 and KT-66, for different tones without re-biasing the amp.

The two output tubes do not need to be matched in any way—you are free to experiment with any combination you want! Likewise, the two preamp tubes can be any combination of 12AX7, 12AT7, 12AU7, 12AY7 or 12AZ7.

The BiValve-30 delivers tones from smooth and clear to very aggressive overdrive, like the UniValve, but with more power and a much more compliant output transformer for thicker lows. It is easily capable of driving a 4x12" cabinet, yet quite small and relatively light. Finally, it has a built-in Hot Plate® Power Attenuator that allows for full output distortion at almost any volume. The unique combination of our touch-sensitive input circuit and the wonderfully active and reactive tone control section (that we slaved a year to perfect) make for a front-end that really responds to subtle and not-so-subtle changes in the signal being fed into the amplifier either by the guitar or any effect that may be between the guitar and the amplifier.