This is very surprising to me. I have a background in psych and typically am very wise to the placebo-type issues with audio...I have not done blind abx testing, mainly because I don't prefer to turn my hobby into a science experiment, but the ISO regen with the stubby connector and LPS2 PSU sure seemed to make a difference to my ears. I'm really shocked to see the measurements not indicate *anything* going on.
I've always battled within my mind re: objective vs subjective. I tend to always fall on the side of science, but on the other hand, it doesn't make sense to me that *everything* audible is measurable. I really don't know what to make of this, because this was quite a stark contrast when I first installed this thing. There is a possible confounding variable, however, in that I did upgrade to a different amp (Woo Audio WA7 with tube PSU) within 30 days of adding the Iso Regen...but I felt I had accounted for that.
Very odd.
* Reset button pushed *
It is not surprising that the device seemed to make a difference to your ears.
All we can say here that, most likely, the device has not been AB tested blind (as you already stated).
The ISO
can make a difference in some cases. Not in sound quality but in suppression or removal of weird noise(s) due to a ground loop.
The fact that 2 things changed (one of them adding euphonic distortion) doesn't help with the assessment of the situation.
I totally understand the desire not to turn enjoying music into testing with rather flawed measuring equipment (the brain).
The brain should be used to enjoy reproduced music, not to analyze equipment.
I do that myself as well, unless I really need/want to know something and try to get rid of biases.
The ability to account for various biases is heavily underestimated by humans. Especially those that feel they can take them into account.
Most folks analyze with crappy/unreliable and fallible equipment (acoustics, ears, brain, state of mind, time).
I would not recommend to draw any conclusions based on personal observations, other than one likes it or not, where the most important bias (KNOWING what is in the chain) is not removed.
Those that insist to test this way might end up in a very expensive shopping spree.