Rhea and tube noise....????

I have auditioned the new Aesthetix Rhea (early version) and was pleased with it. I only had it in operation for a few days. However, I am getting reports for users that the unit does exhibit some tube noise. The suggested remedy for this is NOS tubes, which could be costly.

Here are my questions: Any Aesthetix Rhea users out there have experienced tube noise with their unit??? If so, what was the solution??

Have any of you replaced the tubes with NOS, and if so....which ones....??...and at what cost???

Thanks again everyone!!
I'm not Aesthetix Rhea user but I guess that for $4k+ the unit should exhibit no tube noise whatsoever.
You can shop for small signal NOS at www.audioclassics.com and they have a very good price breaks on them.
I read somewhere (probably here) that early Rhea's had some kind of problem that caused tube rush to be louder than later Rhea's. I think it's something they can fix. I'd contact Jim White.
When I first got my Rhea there was a bit of "tube rush" like noise. It went away during the first 50 hours of use, and it's been dead-silent in operation since. BTW I have a low-output MC cartridge, so gain is set pretty high.
The Rhea is like the Io - dead quiet with the stock tubes. Due to the amount of gain being generated in both units, the first gain stage tubes are critical. The factory very carefully selects these tubes for low noise; so people changing these should be careful to get very special tubes indeed. I use an Io signature with a 0.4mv MC cartridge and have no tube noise at all, and the audio circuits of the Rhea and Io are substantially similar.
Thanks to all....a big sigh of relief.