The title doesn't get my idea across. An amplifier without a knob. I am confused on how you would use the fosi audio V3 with a preamplifier when the V3 has a volume knob itself. It would be like most monoblocks found on large systems and i would see an advantage of having a single knob control up to 6 fosi amplifiers. Is what i am saying making sense? Is there a reason to have 2 volume knobs? How could you use a preamp on Fosi audio amplifiers?