Chashas1,
My amp is a Rogue Audio Tempest bought from a dealer that does not carry Harbeth. My thought in posting this question is to get input from those directly familiar with Harbeth and tube amps with 4 and 8 ohm taps. BTW all my current system- amp, cd player, speakers, turntable, phono preamp, and subwoofer has been purchased from dealers.