Doesn't matter who makes it. All amplifiers made these days have
distortion
byproducts well below audible threshold. Especially compared to the
distortion that arises from driving your amp into clipping, which is
surprisingly common.

Eh maybe, but I refuse to believe that a Jensen or Dual amp is going to
sound as good and clean as a Zapco or Xtant.

Why? Because the price tag says it does?