I tried a cryo'd HBL8300 (Porter Port) and a normal 8300 in my system, first with the EMC-1 UP and then on my Aleph P. Couldn't hear a difference. I then simnplified to just using the EMC-1 alone, fed DIRECTLY to Senn HD600 cans through the RCA outs via adaptors (surprisingly nice match, yet a bit loud), and STILL couldn't hear a difference. Thought I'd at least catch some difference in the top octave somewhere, but nope.
All circuits are discrete 83803EST dedicated lines, 35' long, via my PCKs. Again, my mind's open to cryo's possible effects, but I remain believing that it's the possible reduction of dielectric effects of the INSULATORS consequent to cryo-ing their adjacent conductors that yiels a possible improvement. Yet for some insulators (especially Teflon), there are better ways to accomplish this "curing", but my intent isn't to bend the thread here.
El, I too would REALLY simplify the test systems, to the point of allowing at least 48 hours gravitational settling and isothermality before swapping the test objects. Using cans directly from a source might at least reduce other variables in the chain, too. Bigger problem is going to be the implementation of at least single-blind methodology, preferably in the dark, unless you can recruit your wife with a bribe of some sort...and how to categorize your results, and their interpretation. (PS Jewelry usually works with Ellen!) Have fun.
