ARC REF 3, Nagra PSA, & Phase Inversion

Last night, while I was auditioning a Nagra PSA for my primary system, at the suggestion of a friend, I inverted the phase on the REF 3. The sonic effects were remarkable. The speakers disappeared further. The sound stage became much more defined and deeper; it extended a little more forward, quite a bit more backward, and even a little wider. Imaging, which had always been quite good, was also markedly improved. And the overall musical presentation was more relaxed (for lack of a better word) and musical (to my ears). I was really shocked but also quite pleased with the changes I heard!

Can someone explain what exactly goes on with phase inversion and how it can cause the changes I heard (and perhaps other changes that occurred and I did not recognize them)?

Thanks in advance!
I would guess the recording was recorded out of phase, and you corrected it. Or something is wired out of phase in your system, and you corrected that.
Many recordings are recorded out of phase, or some instruments in the recording out of phase, so that is why a phase switch can be useful to correct this, if it is important to you.
Were you using the unbalanced (RCA) output of the preamplifier? If so, the REF3 usually sounds better in the inverted position.

For the evaluation I was doing, I was using the balanced output. I am going to talk to my friend who suggested the inversion and get his explanation, then share it in a subsequent response for this thread.
My friend who suggested I try the phase inversion explained his rationale this way. He said that most tube preamplifiers do not have a second amplifier stage ( although a few do, according to him) and thus are out of phase with a solid state amplifier. Thus inverting the phase should bring a system's tube preamplifier (in most cases per his clarification above) and SS amplifier into phase. At least that is what I gleaned from his comments. Whether the explanation is "correct" or not, there must be something to this, because when we tried the phase inversion with the SS Nagra PSA, I easily noticed all of the nice sonic improvements I mentioned in my original post for this thread. And this was evident on all of the 10 to 12 recordings we listened to. On the other hand, when I switched to my Luxman tube amp, phase inversion in the same system did not improve the sound, and in some ways it was less "good."
What did you think about the Nagra PSA?

I now own that Nagra PSA! It is by far the best SS stereo amp I have heard at anything near its price point. It presents quite a different sonic landscape than my Luxman MQ-88, but I like the Luxman just as much so I am keeping both amps. This probably qualifies as conspicuous consumption but I don't care!

The Nagra is fast, accurate, musical, and seems to have more power than its rating. The music flows effortlessly. The highs are definitely improved over what I hear with the Luxman, and the bass response is so good that I have not yet bothered to tie in the REL B-2 that I always use with the Luxman. And I probably won't.

My speakers in my main system are the Verity Fidelio Encores. It is perhaps worth pointing out that when Verity shows their speakers at shows, they typically use Nagra amps. From what I have heard so far, I understand why they do!
May I ask what other preamps have you used with the Nagra PSA apart from the ARC Ref 3? Have you tried a passive pre with the PSA? What are you thoughts on other preamps used with the Nagra PSA? Thanks in advance.
The only other preamp I have used with the Nagra PSA was the Shindo Aurieges in my secondary system. I wanted to hear how the PSA would sound versus the Accuphase P-3000 that I use in that system. Both were excellent pairings with the Aurieges, with the Accuphase sounding more full and the Nagra sounding more detailed. I have heard the PSA with the AR Ref 5 at Don Better's and it was superb. Likewise the PSA with Ayre's top of the line preamp, which I do not like as much as the AR preamps named above. Aside from impedance matching between other preamps and the PSA, I believe the next most important criterion is hearing them together, which I realize you already know!

Best Regards,

Hi Steven,

Thanks for the prompt response. Reason I asked the question is I am considering the PSA but cannot justify spending the same amount of money on the Ref 3 preamp. Although I have no doubts the Ref 5 would evidently be a major step-up from the Ref 3, that unit is financially beyond my reach. Was hoping a more modestly priced preamp would still cut it with the PSA. Anyway I will have a chance to listen to the Nagra in my system soon and see how it will match with my Harbeth speakers.