04-18-2020, 01:20 PM
0.8 ohm secondary is not important, the turns ratio is to a degree.
You need to match 2.5kOhm to3 Ohm, that is your turn ratio is 29 (30 is ok or close).
The tap ..... without knowing the position of the tap (it is likely not a centertap) we don't know the exact feedback gain.
However I think you might be able to do without it.
Or some resistive divider AC blocked through capacitor feedback could be fashioned.
A Hammond xfmr, 125SE, almost any size, like 125ASE, will do.
Black and Yellow is close enough for your speaker and the tube.
You need to match 2.5kOhm to3 Ohm, that is your turn ratio is 29 (30 is ok or close).
The tap ..... without knowing the position of the tap (it is likely not a centertap) we don't know the exact feedback gain.
However I think you might be able to do without it.
Or some resistive divider AC blocked through capacitor feedback could be fashioned.
A Hammond xfmr, 125SE, almost any size, like 125ASE, will do.
Black and Yellow is close enough for your speaker and the tube.
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