Besides the high distortion and low power and lousy frequency response into reactive loads(speakers) SET amps are inherently non-linear due to single ended topology. They compress the negative portion of a wave form relative to the positive side. And this can't be cured. It's due to single ended topology. Then again it's what produces the high second harmonics in an SET that many people love.
New Western Electric 91E 300B Tube Integrated Amp REVIEW !