Has anyone replaced tubes in Aesthetix Rhea ?

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.

Stew3859,

So did you only replace the 6922's?

No, Dan. The first thing I swapped out was the 12AX7LPs which are at the first gain stage (V1 & V2 in each channel). The improvement in soundstaging and three dimensional layering was nothing short of spectacular. The swap did not, however, kill the tube rush. Next I swapped out the Sovtek 12AX7WBs for EH 12AX7 gold pins. Perhaps slightly warmer sound, but still no improvement in tube noise. The last tubes to go were the Sovtek 6922s in favor of the Siemens 7308s. Thats where I lowered the noise floor considerably. I can now listen virtually as loud as I dare and tube noise, although still present, is not audible from the listening position and that is at two gain settings higher.