Here's a question: what is the absolute cleanest CD you have ever heard? What I want are a few CD's which can be used to evaluate my gear. There should be vocals, good soundstaging, and MOST IMPORTANT OF ALL, absolutely no audible distortion. If the listener can hear any distortion on instruments or vocals whatsoever, the it's the equipment - period. Rock, pop, jazz, whatever. Just looking for a few "ultimate" CDs. Not SACD, not DVD-A, only CD. Any suggestions? Thanks, Martin.