I have a large collection of mostly vintage amps, preamps and tuners. All have been completely dissambled, updated and restored to better than factory new. For instance I'm lucky to have an industrial pc board washer and a paint shop to put automotive finishes on my gear. I regularly swap components back and forth and the differences in sound quality are dramatic in some cases and barely audible in others. Minor bias adjustments have a huge impact on whether an amp sounds slightly bright or warm. I have yet to find an original, older amp (i.e. broken in) that had the correct bias setting either to factory spec. or set for lowest distortion. I have never been able to hear a difference between cables and feel certain that impedance and component matching have the biggest effect on why components sound different in different systems. As with almost everything else in life, maybe yes maybe no, depending upon many factors. Psycology definitely is a factor, as is the state of your sinuses and barometric pressure.
