Willem, thanks for the Harbeth article. As it turns out, because previous sources used hadn’t the option of adjusting output amplitude, I simply failed to consider its potential impact on overall reproduction. It helps to understand why, between two different laptops, there was such a significant difference in sound quality between the two. I don’t know if it’s the only reason or even a reason at all, but the laptop with the least desirable sound, Sony, had an output setting nearly at its highest level; the other, an Apple, (the one now connected) had its setting close to null.
I will continue to use a laptop in this setup primarily because it sounds wonderful as well as the fact that it provides a means to easily and conveniently sample various artists and genres for ultimate potential use in my main system.
My primary setup consists of several sources including shanling CD 100, Angstrom 200 preamp, Ayre V3 amp and Martin Logan Ethos speakers. Though quite different in several ways I enjoy both systems very much.