NFB on multi-tap OT

[pdf64]

100k NFB @ 4 ohms= 141k @ 8 ohms = 200k at 16 ohms.

I prefer a 27k resistor in series with a 220k pot at @ 16ohms

I think those values are more relevant to 5F6A based circuits, rather than 2 channel BF amps, whose NFB circuit resistances are much lower

[Roe]

100k NFB @ 4 ohms= 141k @ 8 ohms = 200k at 16 ohms.

I prefer a 27k resistor in series with a 220k pot at @ 16ohms

I think those values are more relevant to 5F6A based circuits, rather than 2 channel BF amps, whose NFB circuit resistances are much lower

yes, but it is the ratio that matters. the BF uses a 100R, not the 5k pots

[pdf64]

100k NFB @ 4 ohms= 141k @ 8 ohms = 200k at 16 ohms.

I prefer a 27k resistor in series with a 220k pot at @ 16ohms

I think those values are more relevant to 5F6A based circuits, rather than 2 channel BF amps, whose NFB circuit resistances are much lower

yes, but it is the ratio that matters. the BF uses a 100R, not the 5k pots

Absolutely, but I suspect that such a leap in circuit analysis may be lost on @espinete 's current level of understanding

[Roe]

100k NFB @ 4 ohms= 141k @ 8 ohms = 200k at 16 ohms.

I prefer a 27k resistor in series with a 220k pot at @ 16ohms

I think those values are more relevant to 5F6A based circuits, rather than 2 channel BF amps, whose NFB circuit resistances are much lower

For a blackface ab763 circuit (with a 100R NFB resistor in the phase inverter instead of the 5k presence pot), you can try a 470R resistor (instead of the 27k) and a 5k pot for variable NFB (instead of the 220k pot)