Aesthetix vs. Allnic vs. ARC ph7

This guy hand selects low noise tubes for the various positions. I forget which ones as I had just borrowed the unit for a week.

Jim McShane's tube selections for the Rhea are:
(4) "Mullard" reissue long plate 12AX7's
(4) Sovtek 12AX7LPS
(2) Genelex reissue 6922EH

The big deal is that Jim goes through hundreds of tubes to get especially low-noise sets. Unfortunately, this means he rarely has sets to offer these days because they have become popular with Rhea owners. I'm on the waiting list for a set.

There's some nice synergy at work here, that other brand combinations of new-production don't seem to achieve. Call it "magic" if you like.

HTH

Sorry for the delay in getting back to this thread.

Lew, the IO has a lot more space around the coupling caps than does the smaller Rhea or Janus. That's part of the reason I haven't changed the output caps in the IO as I don't have the real estate to put in the pop can sized Duelunds. I'll probably end up with Mundorf silver/gold oils there. What caps did you use in your Janus?

Analogluvr, no my Herron is the VTPH-1 while the Rhea was a standard non-signature. When Keith voiced the VTPH-1, he used Russian tubes so they work better there than with the Rhea. I remembered I tried NOS tubes with Herron and they didn't make that big of a difference. I don't recall what brand of tubes I tried but I have Tele's, Bugle Boys, RCA's and EI's on hand. Overall, the sound quality of the small signal Russian tubes are crap IMO.

The Rhea however (and the IO for that matter) is far more sensitive to tubes and can sound horrible or great depending on what tubes are used. Had I heard the Rhea with only Russian tubes, I would have never liked it enough to go further along that path. If you had swapped tubes between the Rhea and Herron and used a decent 6922 I think your comparison might have come out much closer. You might have still preferred the Herron but you would have gotten a taste of what the Aesthetix brings to the table.

Dear SBrown,
I don't blame you for missing the answers to your questions in reading my rather dense post. The Janus uses only two capacitor values in the coupling applications: 0.22uF and 2.0uF. I replaced the two 0.22uF caps used in both the line stage and phono stage sections with 300V-rated Vcaps (requires four capacitors, total). The choice of 300V rating was determined for me by the fact that they are only a bit larger than the OEM polypropylenes, whereas the 630V-rated Vcaps are quite a bit fatter and longer. I replaced all of the six 2.0uF metalized polypropylene film caps with 2.0uF polystyrene film and foil capacitors. The latter are a bit larger in diameter than the originals but they do fit. I changed nothing else; the tubes are still the OEM ones. The transformation in sound was quite remarkable, more obvious than expected.

I do also have a new tube set from Jim McShane, but I have not installed them as I see no reason yet to do away with the OEM tubes.

One thing that has not yet been addressed in this thread is impedance compatibility. If the OP is using the MC601 preamp listed in his system description, and plans to connect the phono stage to any of the preamp's inputs other than the unbalanced "tuner" and "aux" inputs (which have 50K input impedances), there may be issues with most of the phono stages that have been mentioned.

The input impedance of the MC601's balanced input does not appear to be specified. And the input impedances of the unbalanced inputs other than the two I mentioned above are only 10K. I'm pretty certain that a 10K load would be decidedly non-optimal for the Rhea and the Herron, and possibly also for the Allnic. And ARC specifies for the PH7 a recommended load of 50K to 100K, with 10K indicated as "minimum."

If the OP's intention is to connect the phono stage to the unbalanced tuner or aux inputs of the MC601, however, there won't be an impedance compatibility issue with any of these phono stages.

Regards,
-- Al