Shunting signal to B+ instead of ground

[anson]

because that way current can return back to the output tranny (as there doesn't seem to be any reason why that current should play with B+ circuits), and also doesn't have to go through any elecrolytic caps on its return home.

Reading that over again, I really don't know what I was doing bringing the OT into the subject, I think I had two different things on my mind. What i was really trying to say is that it seems that the LTP, the LTP grid resistor, and the NFB should share the same reference.

Don't forget that by moving that cap to the B+ you basically removed your NFB, and left the PI with a kind of mild NFB and PFB combination.

Would the mild NFB and PFB be introduced as result of something introduced through the newly made B+ connection, or would it happen because the signal can't be sent from the tail resistor/NFB shunt resistor to the 2nd stage grid anymore? I have to admit that I don't entirely know the role that that cap has. The only role that I could clearly understand it having is to keep AC off the grid so that the second LTP stage can amplify the differernce between the grid and the cathode. So then I suppose it should sound similar wheter it's connected to B+ or gound.

[pdf64]

'The only role that I could clearly understand it having is to keep AC off the grid so that the second LTP stage can amplify the differernce between the grid and the cathode'

No, it's part of the feedback loop, sending a portion of the output signal to the second grid, which is the inverting input of the power amp 'op-amp'.
See
The Long-Tail Pair

[Merlinb]

Would the mild NFB and PFB be introduced as result of something introduced through the newly made B+ connection, or would it happen because the signal can't be sent from the tail resistor/NFB shunt resistor to the 2nd stage grid anymore?

The latter. By moving the cap you're left injecting the NFB signal into thte tail (i.e., cathodes) of the LTP. It will be amplified by each triode, and will be out of phase with one output (NFB) and in phase with the other (PFB).

[teemuk]

And I still dont get how that would make anything sound better?

Perhaps because "better" in this case seems to be a highly subjective conclusion to which the person making such claims has likely arrived without even scoping or blind-testing the difference.

[anson]

I admit that I haven't scoped a single thing.

[anson]

The latter. By moving the cap you're left injecting the NFB signal into thte tail (i.e., cathodes) of the LTP. It will be amplified by each triode, and will be out of phase with one output (NFB) and in phase with the other (PFB).

Thanks, I've been wondering how that works for years!

[wizard333]

Perhaps because "better" in this case seems to be a highly subjective conclusion to which the person making such claims has likely arrived without even scoping or blind-testing the difference

Perhaps not.

Better based on running bleeders across plate resistors instead of to ground many times, better based on extensive testing not only by my own ears, which are pretty sensitive, and fingers, which are just as sensitive, but by many other players who have played the amps in question and who participated in the testing.

The problem with some people is, they worry to much about the 'theory' or 'what it looks like on a scope' and draw their conclusions from that without EVER having actually put the thing to the test in real world situations, without ever having put the thing in the hands of real players to get their opinions, or they aren't good enough players themselves or experienced enough performers to know how things are going to sit in a real mix, to be able to hear or feel good from bad. A scope is never going to be able to tell you those things.