Has anyone replaced tubes in Aesthetix Rhea ?

Patrickamory, I had earlier spoke with Jim White about the power regenerator and he simply suggested I try listening to the unit plugged directly into the wall because of the size of the transformer. I do not have it plugged into one of the regenerated ports and, in any event, I tried to go directly into the wall, but it did not solve the problem. Also, the Rear Projection TV does not seem to have any effect on the unit. The other night when I had friends over, the TV stayed off. I intend I calling Jim White if the replacement tubes don't do the trick.

OK, the Telefunkens arrived today. Now mind you, the Rhea has been consistently quiet so it came as no surprise that I did not hear the ringing which I had been hearing when the Telefunkens went in. What I'm a little disappointed with is the fact that in terms of tube rush, I do not find the Telefunkens any quieter. At a certain volume level, which I consider moderate, at the listening position, I can hear the rush of air coming from the speakers. Its not a ringing and I accept this noise as being entirely normal. I never thought tubes would be silent or even whisper quiet, but I did think from all I read and heard that the Telefunkens would be quieter. Not so. I understand that Jim White hand selects the Sovtek 12AX7s he puts into the Rhea for low noise so either he does a very good job, or the design of the Rhea is just a high gain unit which is prone to a fair amount of tube rush. Anyway, my question is this: I replaced the 4 12ax7s in the first input gain stage. I'm still aclimating myself to the Telefunkens, and at most I hear a slight warm and bloom in the midband. Rhea tube complement (each channel) is V1 & V2 (12AX7LP—factory graded low noise), V3 & V4 (12AX7WB) and V5 (6922). Do you think I can get the unit to run quieter by swaping out the 12ax7WBs or the 6922. The folks at Musical Surroundings which distributes the Rhea said some people have had good luck with GE 5751s. I'm wondering if I go with 5751s in V1 & V2 and the Telefunkens in V4 & V5, do you think it will lower the noise floor. Should I swap the Sovtek 6922 with a Telefunken or Mullard 6DJ8? Any ideas where to go from here in terms of improving the performance of the Rhea be it to have it run quieter or richer? Thanks.

Stew, imo you're not going to get it quieter by replacing the stock tubes. This is particularly true of the 12AX7s, and most particularly true of the first gain stage. Jim White has gotten the "low noise" issue pretty well nailed with his selected stock tubes. You WILL change the sonic character of the Rhea by swapping the various tubes, but you won't make it quieter in the process (except to eliminate the ringing if that's an intermittant tube problem).

FWIW, I've spent the past two weeks swapping vintage tubes into my Aesthetix Io and listening to the result. Tonight I pulled all of them and went back to all stock. The sound changed with each change of tube, but not for the better overall in complex orchestral music. I may play with this again later and change my mind, but with our local audio group coming to my house this weekend for a listening session, I wasn't about to leave the system with the sound I'd gotten thus far. And, clearly, others have had different experiences.
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Rushton:
I am pleased to report that I have lowered the noise floor significantly by replacing the stock Sovtek 6922s with Siemens 7308s. I was able to raise the gain setting from 50 to 62 on the Rhea, which is a two-step jump and at this higher setting I can now listen virtually as loud as I dare to without hearing any tube noise from the sitting position. The ringing is gone as well. Before receiving the Siemens I had swapped out the Sovteks with a second set of Sovteks I had in an old Audible Illusions Modulus and the noise was still present. So I'm quite certain the Siemens are responsible for the improvement. The 6922s in the Rhea operate as an output buffer. I encourage all Rhea users to try a vintage NOS 6922 or a 7308 in lieu of the stock Sovtek if you are experiencing excessive tube noise as I was. I am very happy at this moment.

Glad to hear this, Stew! Congratulations on finding a solution, and thanks for sharing the results.