In the vein of a previous post I made on the difficult-to-interpret term "texture" in sound, similar problems arise with "noise/floor" and "distortion", which can also be very misleading terms indeed.
When relating to the negative effects upon the reproduction of tones/overtones/harmonics in the FR, this is a veritable minefield as to the
precise factors as cause, and their degree within the mix...viz equipment components' (including cables and connectors) levels of inductance/conductance/capacitance/impedance. And when you factor in what resides in one's
mains supply and the environment's pervasive EMI/RFI interference, the task of even just
searching for it let alone
quantifying and
reducing it is a mammoth one to say the least lol!
In addition, there's often little correlation between (questionable)
instrument measurement of values and what we actually
hear/
perceive/
interpret.
Therefore, all this interplay is going to make trying to pin down any 'alteration' in sound to a
specific component's 'noise floor' or degree of 'distortion' a very murky undertaking indeed.
I submit that this also applies to statements such as re. voltage/current levels exchanged between components. I personally believe this area is much more complex than may at first appear...for example 801evan's mention of higher voltage increasing distortion did at first seem to explain the occasional slight edginess induced in my TT2/mscaler-fed Hypsos/OOR combo with Hypsos at 28V instead of 24V - this latter 'recommended' level giving a rather flat, lifeless presentation in my system. HOWEVER, replacing the (extremely good) 2.5mm DC connection with my own version of the 4 pin 'FPL' - still at 28V, removed any excess entirely.
And by the same token, using OOR's 'bypass' function, thereby outputting at max volume, one would expect this type of 'distortion' to perhaps result to a certain degree?...but no, the opposite in fact - a bass-washed, poorly balanced, lacklustre sound. One could argue that the necessary lower output from TT2 had a part to play, but this
interplay also would appear to show IMHO that complex nature of exchange between components I mentioned earlier.
So, my point is that I believe we all need to be extremely careful when making statements on so many of the aspects of sound reproduction to which we love to apply such open-to-discussion, often misleading/misconstruable 'audiophile(?!) terms.
Sorry for any indigestion I may have caused...