Has anyone replaced tubes in Aesthetix Rhea ?


I have developed a high pitched hiss from the stock Sovteks which came with my unit. I believe its at least two or more of the 12ax7s which are in the first input gain stage as I hear it more or less equally out of both channels. I was wondering if any Rhea owners have rolled the tubes in their units and, if so, what prompted the swap and what success you have met with.
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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.
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.
Thanks, Stew. I was contemplating a cartridge upgrade but I might do this first instead. Probably a cheaper tweak than a cartridge.