HI Uncle Erik,
I used a Conrad Johnson PV10 for many years and enjoyed the sound. However, periodically I'd get whistles, weird rushing sounds and other noises. These sounds drove me nuts! The sounds would go away, sometimes on their own, sometimes with a touch or tap to the tube. I tried many tubes and dampers, but the sounds would always return. I had CJ replace the capacitors, all without success. I spoke with others who had tube preamps, and they too, occasionally had similar issues. I replaced the tube preamp with one from Wyred 4 Sound. I would say that while there are big differences in the quality of music reproduction, the Wyred preamp was an acceptable change. It provided greater bass and treble extension, significantly better detail. It lacked something in the vocals. Overall, it provides a more accurate sound.
I have greatly appreciated the lack of attention that SS gives and don't want to go back to tubes.