Getting hifi bandwidth out of an SET is challenging when the full power is over about 8 watts or so. Usually the bass is sacrificed so that the output transformer can make it to 20KHz.
Often that works, since the speakers that have the sort of efficiency you need sacrifice bass response for efficiency so you wouldn't hear the bass rolloff in the amp anyway.
However before pulling the trigger, you might want to audition a triode push-pull amplifier of the same power. You may find that the decreased distortion and increased bandwidth to be helpful on the resolution side, and the simple fact that a push-pull amp has less distortion means that you have a greater percentage of usable power. SETs really should not be pushed past about 20% of full power, as distortion at power levels above that in the transients of the music cause them to sound very 'dynamic'. Maybe this is me, but I prefer to hear the dynamic quality of the music, rather than distortion masquerading as 'dynamics'.
Often that works, since the speakers that have the sort of efficiency you need sacrifice bass response for efficiency so you wouldn't hear the bass rolloff in the amp anyway.
However before pulling the trigger, you might want to audition a triode push-pull amplifier of the same power. You may find that the decreased distortion and increased bandwidth to be helpful on the resolution side, and the simple fact that a push-pull amp has less distortion means that you have a greater percentage of usable power. SETs really should not be pushed past about 20% of full power, as distortion at power levels above that in the transients of the music cause them to sound very 'dynamic'. Maybe this is me, but I prefer to hear the dynamic quality of the music, rather than distortion masquerading as 'dynamics'.