Just a suggestion here since I see you used a PS Audio Power Plant (a regenerator)...
Quite a few years back I tried a PS Audio Power Plant (the 3-something model, PS300 I think) on my Stax SR007 (mark 1) phone / 007t amp system,
and it completely ruined the sound (I described this sometime back here in the forums somewhere).
The amp started running very hot, the tubes lit up brighter than before, and the sound turned bright, aggressive, with thumping bass, and it was unlistenable.
This was completely opposite to the mellow sound I heard without the power plant.
I later used a Shunyata Hydra with this system with no problems, just some subtle improvement in the highs.
I actually called PS Audio to ask if this was normal and they said it does happen with some tube amps, and in fact this was a common complaint.
They took the amp back and refunded my money.
So I think the Power Plant may have wrecked the Stax amp sound.
(And God knows what it did to the other amps.)
Peter's answer to your question on the forum HCFR:
“Ce témoignage est à prendre en compte, c'est sûr.
Mais je ne penses pas, non, que le P3 ait altéré le son du 007.
J'avais fait des essais chez moi à plusieurs reprises, et j'avais trouvé plus de précision avec le P3
Ensuite, le test du samedi soir dont j'ai joint plus haut la feuille, montre que j'avais préféré le 007 connecté au P3 plutôt que le RKV...
à suivre !
"This testimony is to consider, for sure.
But I do not think, no, the P3 has altered the sound of the 007.
I did some tests with me several times, and I found more accurately with the P3
Then the test Saturday night which I attached above the sheet shows that I preferred the 007 connected to P3 rather than the RKV ...
Good ; to follow!
NB: The SRM 007T was used as the reference amplifier (A) the Saturday night for an pre-test in blind. This pre-test was canceled after only one music track due to the late hour and the fatigue of the one of the participants.
The test was therefore postponed the next day (Sunday morning) with this time the RKV-Wee amp as reference (A). This true test in blind was produced in its entirety Sunday morning (with 5 titles music) as opposed to the pre-test aborted Saturday night.
Edited by eric65 - 9/18/13 at 8:03am