Rogue Sphinx v Nakamichi PA 5 MMKII and a preamp

We agree to disagree. It's your speakers, your system. I just had a different opinion and responded. No, I have not compared all the speakers in question side by side but have been all over the country for many decades listening to thousands of different speaker systems and I do have a pretty good ear....Enjoy those Infinity's!

Well there we have it.
I guess you have had them all  in your home and compared them all side by side so to speak ?  I know I have .   As a matter fact had Vandersteen 2Ce and 2CE sig 3 times. Great speaker but not for all of us.
Each to their own.

Yes. I have heard Infinity 2.5's. Also Their IRS systems. Not impressed.

Infinity RS 2.5's??? Up against the new Vandersteen's??? Not a chance in hell......

Umm what  would I replace RS 2.5s with?  Have you ever heard a pair? I have had   Vandersteen, Von Schweikert PSB, Mirage, ADS Energy,Polk Canton and so on.  They all have their strengths but  The 2.5 is better in almost every way.  The Rogue is not doing anything wrong it just sounds a little  veiled and not very vibrant compared to the other gear.

If you're having that kind of trouble with the Rogue, maybe you should consider a different pair of speakers.

I got the Rogue  Great anp but does not seem to be a good match. Very dark with a rolled off top end.  Tubes big surprise.  Switched back to the Yamaha  M4 and CX 800U and it was like a blanket had been taken off the speakers.  Larger stage more dynamic  yes brighter but way more alive. I kno0w I can change out tubes but not looking to go down that never ending road  The age of a unit does not matter to me.  I find most older gear sounds more musical and with more body verses much of the hyper detailed thin sounding outright weird newer affordable gear.  i hear this from others all the time.

Go with the Rogue. The Nakamichi is a 30 year old amp and they been out of the Audio business for years. Rogue is only a phone call away if you ever need service!

The Nak is a nice amp and with a really nice preamp probably going to outclass the Rogue, but with a NAD or Rotel preamp I’d lean back to the Rogue. I personally haven’t heard the PA 5 MKII, but knew the PA 5 well. Nothing wrong with Rogue either, but yes the Nak is going to grab your Infinity’s better. You throw a preamp like a ModWright SWL 9.0 SE on that Nak and it’s another story. The Nak is an easy amp to modify too.