Thanks everyone for responding.
I apologize for any confusion and will attempt to be clearer.
- I have been using the Leedh volume control in my Lumin U2 streamer to good effect. It is clearer than the preamps I have or have tried. However, there is some loss of body or warmth.
- The problem I am describing happens with direct dac to power amps or going thru an integrated amps preamp out circuit.
- Thanks, @carlsbad2. When the problem showed up in the right channel, I had moved the cables from an integrated amp to the monoblocks. I didn't touch the source connections; all other connections remained the same. I went back to the integrated, and everything worked as expected. I think your suggestion to keep changing equipment is the only option I have.
- @zlone I've checked the cables and connections, including manipulating them to see if there is a faulty connection somewhere, but haven't located it if its there. Will recheck some more.
Again, thanks everyone.