SET amps sound good in the midrange and higher frequencies, but the real thing to listen for is bass performance. That's the hard part for a SET amp. Most loudspeakers require electric motor braking (literally) because the main part of damping in the T/S specs is electrical, not mechanical. So the output impedance is very important to bass response. If the bass sounds boomy or tubby, try it with a PP amp and see how you like it.