"tube plates ringing" :) Yes! I hear that too. I have two different horns to play with now, one Oris with 110db, the other Orphean with 114 db. And omg, it's a pain to hear all these noises, scary when I change tubes.
To share my experience, I found that cabling is extremely important, and it was a long journey of resistance, so I take my hat off when I see what you did with your cabling. I also don't use any active filters. The other underestimated area was DAC and the front end in general. First I realized how important DACs were when I tried several good DACs, then came the realization that transports too make a huge difference, and the digital cable, although it's hard to find a good one. it IS a journey for sure.
