Soon the greatest potential 'tweak' of all; my Puc 2 lite will get a chance to tweak the Breeze's nose as I'll have a Breeze in-house ready to go note for note with Herr Puc for bragging rights in the living room. Loser gets booted and 'tweaked' over to the headphone system in the office. Should be an interesting fight.
Interestingly, I actually preferred the Audioquest JB (two of them- one serial and one parallel) in both systems to the regen Amber (which I still have) as powered by teradak. The JB's were immediately more musical to me whereas even after break in, the regen has yet to do for me what everyone says it does for them. I just don't hear that it gets more 'musical' when I put the regen in. I keep going 'ummm... maybe this, or a little that?' But with the JB it was immediately apparent on a Beethoven concerto that there was more depth and the strings were beautiful like never before. That's what I wanted the regen to do. Maybe it's because I'm running it into these converters instead of dac-direct. Who knows.
In other news, a Chord Silver Plus USB cable with a jitterbug runs very close some more 'supreme' type cables I've heard. I am interested to see what a Supra will do. Don't love the stock split USB cable included with the yellowtec, though it has its merits. May try a Forza.
I AM, however, loving a very affordable 12 foot run of Mogami Gold balanced digital cable (runs over six feet being touted by some as best in terms of AES digital cable sonics) which preliminarily seems to have a bit more bass impact/depth and top-end clarity than a shorter length (a meter) of blue jean. I did read on that same cable forum that some guy thought the Mogami Gold ran the super pricey MIT Oracle digital cable to a dead heat; hence my purchase of said Mogami. (Didn't have the extra 3000 bucks on hand for the Oracle and wasn't available on Amazon).
Oh and rb, I got a huge shock (not literally though

when I used a cheap extension cord with outlet extender to plug my mx-u8 converter in across the room. Yikes! a hard edgy sound I never heard from the system before. Terrible! So I went direct into wall again and fixed. Yes sir- no double blind testing was needed on that one

I can totally see how something like a power cord can make those musically important differences you write about even with a USB converter. But Selena Gomez!? Rb, really, we need to talk...