The reason we do not offer a lower powered version of the Fet Valve amplifiers is that it is not cost effective to do so. We would still need the three part power supply (high current and high voltage for the output mosfets, low current high voltage for the audio tubes, and low voltage high current for the tube heaters) and would still need the high operating voltage for the tubes, thus a low powered version would simply be throwing away capability with no sonic or cost advantages. The power mosfets we use share without need for external thermal tracking circuits or protection circuits (unlike bi-polar designs) and again, there is no sonic advantage in our designs to using fewer of them.
Frank Van Alstine
