Silver cables and CD players

It depends on the silver and the gauge. Clear Day Cables uses a wonderful sounding silver in both their speaker cables and Hologram interconnects.

PS Audio also uses an excellent silver in their Transcendent series

"Perhaps we can include quality in the scope of implementation."
Not perhaps, we must in my opinion. More often than not, good design and first class material is spoiled by bad soldering and more often than not this is the case even with expensive cables. Material and gauge alone, though important, does not do it.
For further reading I would suggest: http://www.empiricalaudio.com/ and click "Technical Papers "
on the left side of the screen. It makes good and interesting reading.

Aluminum? Why? I don't care about its 'sound', which can't be better than a proper Ag or Cu cable, but mechanically, aluminum has no fatigue strength and won't take much bending.
No fatigue strength means that EVERY mechanical cycle, as you bend the wire into place eats into its lifetime.
And, while I'll admit that cables are'nt subject to much mechanical stress, each time they are moved, they get closer to failure.
Read thru some of the Empiricalaudio stuff and I'll go back later, when I have more time.