Audio Research PH2 or Aesthetix Rhea?

I've owned both and still have the Rhea. Very different sounding units. The Rhea feels more stereotypically "tubelike". Warmer and more liquid sounding. The ARC walks that classically ARC line between a tube sound and SS sound. You get a somewhat leaner sound which feels meaningfully more detailed and articulate. Depending on the rest of the system (mine features an LS-25 and VT 130 SE) one or the other is likely to be a pretty easy call. In my system, the ARC was a little too much of a (ARC flavored) good thing.

BTW - as noted, the Rhea is MUCH more flexible.

One more caveat: Many early production Rheas (like mine) had noise issues. Jim did a no-charge mod for me, but if you're buying used, look for a later example.

Good Luck

Marty

In addition to the additional gain and loading flexibility, the Rhea has three inputs (individually configurable) and 2 main outs - SE out and BAL out. I use 2 tables and run the SE out into my Joule pre and the BAL out to my LS-25. Different amp/speakers follow each pre (effectively 2 systems with common sources in the same cabinet), and each system can detect either of the 2 'tables, switched via remote by the Rhea. For me, this is really useful. To my knowledge, there's really very little out there with as much flexibility as the Rhea.

OTOH, its sonic "flavor" will fit better in some systems and the ARC's will in others.

Marty