Not quite sold on the single driver SET setup

[Poultrygeist]

One major reason I'm sold on FR/SET is I don't have to endure listener fatigue.

It seems that there is an explanation for this as push pull tube amps and sold state amps produce 3rd order and odd order harmonics which can be harsh to the ears. SET amps OTOH produce 2nd order and even order harmonics which are rich and complimentary.

[E-Stat]

One major reason I'm sold on FR/SET is I don't have to endure listener fatigue

There's a lot more behind the causes of listener fatigue than simply the power amplifier topology.

I find that cabling and power conditioning / RFI rejection play a large role when the quality of amplification stages (all of them from source to amp) meet a certain level of quality.

[Feanor]

One major reason I'm sold on FR/SET is I don't have to endure listener fatigue.

It seems that there is an explanation for this as push pull tube amps and sold state amps produce 3rd order and odd order harmonics which can be hash to the ears. SET amps OTOH produce 2nd order and even order harmonics which are rich and complimentary.

Grungy sound is fatiguing; symptoms are etch, grain, shrill highs, spacial vagueness, vague instrument timbres. Likely you agree. And it's likely that poor s/s components have lots of high order harmonic and intermodular distortion that create the grunge.

However the solution isn't necessarily to bathe the sound in 2nd order distortion, either instead of, or to hide, the high order distortion. The real solution is to get minimize the offending distortion, and good s/s does this quite well while not adversely affection resolution and transparency.