I think 'clean power' would be more of a product of a high quality amp,
not
so much from an install. In other words, an amp that amplifies the signal
without a lot of distortion and extra crap. Zapco and Xtant are good
examples of ultra clean amplifiers.

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.