Thanks Eldartford for performing your tests and reporting your observations. In the other thread I laid out some of my conditions for what would constitute an ideal test design so I'm not going to recapitulate them here, but neither am I going to second-guess anything you've done or not done in this enterprise. Obviously the whole process is somewhat of a pain in the ass, and in the final analysis it is still impossible to A) ever eliminate psychology as the primary determining factor in the different results heard by different listeners, and B) to discount the simple truth that even if psychology were in fact the only causal factor at work here, cryo'd outlets (or whatever, especially relatively cheap tweaks) would still be entirely justifiable if we stipulate that the real end goal is just obtaining greater enjoyment from one's system.
I recently got a Porter Port from Albert, which I haven't installed yet because I've been too busy auditioning some tubes. I bought it in order to get a demonstrably better outlet than what I use now, one that is 50 years old and only 2-prong (I have to resort to an added 3-prong grounding adaptor), and unsurprisingly doesn't grip so well anymore. I admit up front that I don't believe the cryo treatment itself will make any significant difference in this application, but since I never seem to get around to actually buying an untreated outlet at the normal price when I'm in the hardware store, I accepted Albert's challenge as the best way to make myself quit stalling and do *something* on this front. I'll report my non-scientific results when it's been installed and auditioned. (I say 'non-scientific' because this will be an uncontrolled, non-repeatable one-time switch between outlets that will have all sorts of other confounding variables not held constant, so any differences I even *think* I hear A) cannot be considered reliable from a reporting standpoint [even by me], and B) could never be positively attributed to the cryo treatment as an isolated factor anyway.)
For whatever it's worth though, here's my thinking about why I don't find the cryo argument compelling as applied to AC outlets *in theory*:
Let's say first of all that we agree to stipulate to cryo's effectiveness as a treatment for permanently improving the electrical conductivity of the metals used in an AC outlet. This is not something which I actually know, but let's just assume that it is so for the sake of argument. To me, this could mean basically two things: A) that cryo reduces the metal's resistance to electrical current flow, and B) that cryo might also reduce some distortions to the signal waveform it passes compared to non-treated metal. Let's assume that it accomplishes both of these things, which it very well may in real life but which I don't know personally for a fact.
Then consider two otherwise-identical brand-new outlets, with one being cryo-treated and the other not. Let's say, for our thought experiment, that the cryo treatment has doubled the one outlet's conductivity by halving its resistance, while also cutting the distortions an untreated outlet imparts on the waveform by half. Even granting that seemingly significant increase in performance, the crux of my argument against cryo-belief rests on this uncontestable fact: the signal pathway represented by the metal conductors residing inside an AC outlet is extremely short, probably under one inch long.
This means that, for any new, decent-quality outlet, uncorroded and with good grip, using appropriately heavy-guage conductors, and being made from a highly conductive metal such as copper or brass, the total resistance to electrical current flow is already going to be infinitesimally small, and its added waveform distortion infinitesimally low. Its very shortness of path means an outlet will never cause more than negligable signal losses at worst, as long as we are not talking about a corroded old outlet with poor grip.
We can also contemplate that, considered as a portion of the total signal pathway that the AC powerline travels on its way from the generating plant to your components, the part represented by the conductors inside an outlet is but a very tiny fraction. Skeptics of course make this same basic argument about high end power cords, but there is at least one big difference which invalidates that analogy: shielding. Upgrade power cords can provide AC line shielding nearest the components which radiate and absorb electro-magnetic fields, while outlets do not have an impact on this parameter, whether cryo'd or not. Additionally, the differences between aftermarket power cords and stock power cords, or from one aftermarket power cord to another, are manifold in nature, involving all sorts of physical variables, while the difference between a cryo'd and otherwise-identical stock AC outlet is strictly limited to the temperature treatment's effect on the metal conductors and nothing else.
So look at the powerline situation in its entirety: assuming that the (already almost unmeasurably low) electrical resistance of this tiny bit of the AC power pathway represented by the outlet is halved through the application of the cryo treatment, the total resistance of that entire pathway will still remain for all practical purposes unchanged. The same applies to the waveform distortion. You cannot successfully apply the 'weakest link' argument to this situation, because you cannot demonstrate that the conductors inside a quality outlet are deficient for their intended function - or if they were, that the cryo treatment would render them significantly less so. If the outlet represents a 'bottleneck' at all, it is either because of the guage of its conductors or (more likely) the integrity of its contact with the plug, neither of which the cryo treatment can improve. If you have cryo'd all of your components and cables including power cords, you still cannot complain that an uncryo'd outlet would add significant distortion to your powerline, because it only represents the final inch of miles of untreated powerline, and therefore could only be responsible for an infinitesimal fraction of the distortion claimed to be caused by untreated conductors placed in this pathway. Unlike claims sometimes made for certain upgrade power cords, you cannot say that the treated outlet will somehow act as an additional level of powerline noise filtration.
Now, consider this as well: it is widely acknowledged and confirmed through controlled-audition testing that even skilled listeners largely lose the ability to reliably distinguish sonically among audio interconnects of various types if their lengths are kept artificially low, say down to only a couple or three inches (this is the basis for the Wireworld Cable Comparator's operation, and a good reason for keeping your cable runs as short as possible). And: that's taking into account that many of the biggest differences to heard among interconnects have mostly to do with things like geometry and dielectrics, not even conductor type - variables which either don't apply or don't get changed when comparing cryo'd vs. non-cryo'd, otherwise-identical AC outlets (sorry to keep harping on the 'otherwise-identical' thing, but from what I can tell a lot of what's been purported about the supposed virtues of cryo-treating outlets lets this vital point slide). And furthermore: interconnects operate directly in the audio signal path and must accurately transmit the full range of audio frequencies plus complex transient information, all at quite low amplitude levels; none of those handicaps apply to AC power conductors, which deal with a high-level near-sine-wave signal, the desired part of which consists mainly of one frequency (an uncritical 60 cycles) which by definition contains no transients and is not complex or particularly delicate, and which will be filtered and transformed before it is utilized anyway.
Therefore it becomes very tough to believe that altering the already entirely-sufficient electrical properties of a very short piece of the powerline conductor outside of the direct signal path, even if by a significant percentage when considered in isolation (though an insignificant amount when considered as a part of the whole pathway it resides within), will ever cause sonic improvements audible at the speakers. I might feel differently about this if the *whole* powerline conductor from powerplant to component could be cryo-treated, but I can't for the moment take too seriously the claims made about so treating less than one inch's worth of that distance. I might also feel differently about this tweak if cryo-treating did anything about staving-off the onset of contact corrosion within the outlet, but it's not claimed to do so.
Of course, all of the preceeding bias also constitutes a third reason, in addition to the two given at the top, why it will be impossible for me to render any meaningful judgements when I install my Porter Port. So I'll be happy just to have an outlet that grips a plug securely and doesn't require an adaptor for grounding. (And I hasten to add that I say all this as an audiophile who hears differences between cables in all system positions, who has heard the effects of powerline conditioners and uses one, and who has even heard remarkable differences among different varieties of resistors in identical values when inserted in his phonostage.)
But even if I suspect that the sound of my system gets subtly (or even markedly) better after switching the outlets, I'll blame that on the inferiority of my old outlet, and not attribute it to the high-tech treatment given my new one (although I'll not dismiss the placebo effect either). And I fully expect to retain the general opinion on this subject I have today in my admittedly cryo-virgin present state, which is mainly to say: A) none of the listening tests that I've seen described so far regarding cryo'd outlets do I consider sufficiently rigorous for drawing meaningful conclusions, EVEN WERE I TO DUPLICATE THEM MYSELF (so please no one take undue offense, because this isn't an indictment of your ears), and B) I feel that most of what has been reported on the plus side in this area is probably attributable mostly to psychological causes (which as I've stated at the top are nothing to be sneezed at, and which might as well be enjoyed by those whose listening pleasure benefits from them). Sorry true believers, but for the reasons I've detailed, I just don't feel there's any more plausible explanation to be had.
