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.
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.