I have never really embraced the concept of tube rolling. Generally I found when I liked the amplifier I liked the sound despite the selection of tubes. Either this or sheer laziness on my part, as I have near 200 tubes that I've acquired in packaged deals and would be surprised if I heard more than 20 of them. The Zana Deux recently has turned this whole conception of tube subtlety on its head. I took out my Mullard ECC35 and plugged in a Brimar a couple of months ago. Forgetting this fact I found myself tinkering with the Zana repeatedly in that period of time. Interconnect swaps, DAC swaps, power cord swaps, and wondering throughout where the harmonious sounds of my favorite component disappeared to. The AD2000 with the Zana, one of my favorite pairings in all hifi-dom, became unabashedly forward and fatiguing. The HD800, with Zana in the role of preamp to a Beta 22, was full of grain, lacking air and for the first time took on an upper-frequency harshness. A couple of days ago I reinserted the Mullard and the harmony returned. The unmistakeable smoothness, linear, fluid transients and wonderful, slightly accented mid-range returned. The AD2000 returned to all its former glory as a fierce, feral ruffian with a touch of refinement. The HD800 is again impeccably clean and effortless.
In the grand scheme of things I'm sure the differences are actually on the subtle side, rather than of the florid night and day descriptors used above, but in the audio world, after a point, those subtle differences can create a wall between the listener and his/her perception of synergism. The Brimar, a tube most people like, pushed aside the unity of a system that I loved and replaced it with something slightly foreign, but unmistakably dissatisfying to these ears. It is a relief that it was only the tube and not the DAC, which I suspected at one point. If the PWD didn't play well with the Zana than the PWD would be the one to go. Thankfully it's only the Brimar that needs to be shipped off.