My feedback on the miscellaneous cables. I tried the XLR, power and USB cables. Note that the differences I speak of are not huge - subtle at best, but definitely there are repeatable in my system.
XLR cable was my first test. Bryston SP3 processor to Bryston 4BSST power. I had to haul the power amp from between my speakers and next to the processor for this test.
First impressions - sounds very bright and hyper-detailed, whats going on? So I added the USB and power cable to my system and let it all run for 24 hrs before I did any more listening. Having done this, my tests were essentially based on listening while I removed the new cables and replaced with my old ones.
Biggest difference came from the USB and power cables on my media player: SOTM SMS200 to Bryston SP3
The treble became sweeter, I lost some of the sharper edges e.g. cymbals, whilst still retaining the sparkle and long decays. Really enjoying it. The other thing of note was that the soundstage shrunk slightly - both height and width were a bit smaller, but retained strong positioning within that space.
I them removed the EWA PC - still as above though soundstage widened a bit. So USB on it's own is making a good contribution to the sweetness.
Move PC to processor and next to my power amp. Not hearing any differences compared to existing PC (note that my existing PC are 15A round pin and fuseless, so this is not a like-for-like comparision as EWA PC is 13A fused. But for both tests the sockets were connected to individual spur sockets, not part of any ring main).
Finally XLR. Now I cannot hear any big difference, but the excessive brightness from first test is gone. Potentially the EWA has more sparkle, but difficult to say it my imagination or real.
For more system context see my profile.
These are good cables and definitely one to think about. I also like the appearance e.g. fist class components, fit and finish. XLR plugs are getting close to bling - lovely. And I do appreciate that you have dispensed with throw-away plastic and are using draw-string cloth bags.
Many thanks
@ABCaudio for the generous offer of the loan. I am still tempted to try the m50 power amp, still scratching my head re my need for XLR connections.