I don’t know. Abbas seems to not have a “standard”. Something today is different tomorrow. I didn’t notice any difference in sound between the two. It may be a case where you need an A/B switch flipping back and forth to notice. The innards look very similar but not exact.
I still have to read a little about the different variants of 6SN7. The most expensive are GEC METAL BASE and BRIMAR "Black Beauty" cost up to £ 1000 per piece.
Okay. Abbas told me recently my 3.2SE DAC requires 200 hours to be thoroughly burned-in. I just assumed (Maybe erroneously) there wouldn’t be much different with the 2.4SE.
Charles
Variance of tubes as a factor makes sense. Abbas utilizes Blackgate capacitors, and many believe they require a substantial burn-in period to sound their best. Then there's lots of wire in the multiple transformers as another possible factor.
Charles