Do you still want to see it?
I have several copies here already.
But as for the Entreq... I'd like to see someone formulate a theory of operation (if there is one beyond "bara lyssna").
You are considering being a volunteer to that effort. You're capable of devising some test scenarios, and have some suitable measuring devices. I'll read what you write. On screen, that is.
Of course, you'd need to create a new thread in the Measurements sub-forum for your tests.
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I'm not immune to tweaking power, I did add a small used Equitech, which, as I interpret it, floats the power to the rack around a new "Earth" reference voltage at the centertap of the isolating transformer. I can't perform in/out of circuit measurements due to a lack of precision test gear here, but it did have some useful results, as in silencing all the other transformers in the rack (at least one was sometimes annoyingly noisy), it has a nice in/out voltage display, and certainly didn't degrade the audio.
I do have an analog 'scope - all I see is a little airborne RF hash at the amplifier outputs - which, as I remember when I looked, was the same whether the equipment was running and wide open (playing silence) or powered off, in the millivolt megahertz range, so, my analysis is it's just the antenna factor at play and doesn't contribute anything to the misoperation of the equipment.
I have a bunch of ferrite clamps (liberated from work long ago) with which I have liberally festooned some of the analog signal and power cables, just in case.
Also, contact enhancement - DeOxit Gold - whose description of its mechanism is similar to that of Stabilant-22, which, if
required for certain signal connectors in helicopter wiring, must have some benefit in maintaining/enhancing connectivity, and be rated as "good stuff".
But the Entreq - especially the units that just hang off your gear with no outlet, I dunno, I see expensive voodoo and can't figure out what it would be doing electrically.