Mrtennis, you might reread the caveats I included earlier. However I might also point out that this experience is from working with literally thousands of tubes. I do agree that the tube type ought not be the criteria for selecting a component, although I would hesitate at buying any new component that uses tubes that are out of production or doesn't sound right with current production. That is one reason we switched to 6SN7s- the current production sound much better than the current production 6DJ8s.
Of course, we have our own reasons for thinking that we have a handle on transparency that allows us these judgements :)
FWIW we tried several types in circuits that were identical in topology, but optimized for each tube. The differences became very clear.
Of course, we have our own reasons for thinking that we have a handle on transparency that allows us these judgements :)
FWIW we tried several types in circuits that were identical in topology, but optimized for each tube. The differences became very clear.