@atmasphere,
Thanks for your interesting comment that loss of bass impact from the passive volume control can thin out the sound and tilt the balance to HF. Actually, I've never used a passive volume control in my own system. I went to a home dealer who used the Music First passive transformer volume control in his system. He then disconnected the Music First and ran the source directly into the power amp with the appropriate CD track to get a comfortable volume level. I couldn't hear any difference with the Music First back in. This same comparison test with any line stage showed obvious veiling added by the line stage. And yes, the veiling added warmth. So that experiment showed that any added electronic stage colors the sound with added veiling. My own experiment at home without the line stage showed the same thing, as I previously described. It wasn't that I heard less bass which created more prominent HF. No, without the added stage, there is improvement in everything--tighter bass, midrange, HF. Put another way, less distortion, less electronic fuzzy warmth. Much more reminiscent of real life--the woman in the well fitted dress rather than body features hidden under an oversized winter coat, the cool snap of the golf club instead of the softness heard in a video system.

