Hi guys.
At last, I've found confirmation of my own findings re upgrading the less-than-overwhelming stock 30V (24V for the 789) wall wart SMPS for the DROP THX AAA...in my case the SE 'ONE' version. And I refer to an extremely reasonably priced Chinese "Ultra Low Noise" LPS, similar it would appear to the sort already mentioned.
As I had a spare 120VA 15V unit over, after making just one do duties for both my Chord TT2 and mscaler, it was a no brainer for replacing an inevitable weak link in the DROP amps. And the transformation was way beyond expectation, surpassing direct HP out from TT2 by a significant margin...
in all areas you can name. Even after many weeks down the road I still cannot believe either what the LPS has achieved here or the true capabilities of the ridiculously cheap 'ONE'...and I have spent a good part of my last few years on head-fi assessing performance of a myriad different tubes in tube amps before going SS...more so than enjoyable 'listening' even!
Hopefully my DIY cable efforts have also helped somewhat (using Neotech Teflon coated solid UP-OCC silver and copper wires)...a nice benefit in using such an LPS that doesn't have captive leads.
For anyone interested I posted much more indepth info on 2 other threads :
https://www.head-fi.org/threads/drop-thx-aaa-one-linear-amp-transformation-david-v-goliath.961629/
and :
https://www.head-fi.org/threads/chord-tt2-mscaler-budget-ss-amp-unheralded-results.961826/
ps. My particular LPS is now $78 on ebay.com, with $40 shipping...crazy price for something that looks pretty well made for a fraction of what I'd have to pay for anything home grown, and has performed flawlessly for about a year now on my Chords. I had to also get a (very) cheap DC-DC Buck step up/down converter for 30V, but it appears one can ask for a specific voltage at the outset.
pps. My headphones are 32Ohm Meze Empyreans which seem ideally suited to the 'ONE's apparently even higher (SE) output at this impedance than the 789(?).
In short, this amp -
with upgraded PS, and in my own system, is about the best value addition I've ever made...by far!