mhore,
listening (mine) impressions on your 12BA6 tube buffer:
1. at initial power on and application of audio signal, not so good to my prefferences, so the cathode R is reduced from 2.36K to finally 560R.
2. Now smooth as silk, "grainy" sound is gone, warm & sweet now.
3. tried the Credence Clearwater cd, takes me back to the "flower people" days
the time when no effects or synthesizer is used in their electric guitars.
driving the JLH 1969 class A dual rail amp.
driver tube at work
there is a big diffrence with & without the buffer on the JLH:
Without tube buffer- sterile/neutral sound, cold sounding, typical of a SS amp.
with tube buffer- Warm & Sweet, once you listened with the buffer on, you"ll never listen without one.
this is my own opinion, you have to try it yourself.