This set has an open circuit primary on the audio driver transformer.
Does anyone know of a replacement or a workaround perhaps by just RC coupling to the output tube ?

Not many good alternatives to finding a replacement audio driver transformer: RC coupling would allow you to drive one of the two triodes in the output tube but you would need a phase inverter tube to drive the other. You could convert to single-ended operation but that would mean you'd need a new output tube and output transformer. Probably would be less hassle to find a replacement driver transformer, or possibly even have the bad one re-wound.

Tim,

If the secondary winding is good from each end to the centertap, you could sub in around 22K resistor from plate of the amp tube to B+ and use a coupling cap of something like .1uf from the plate of the amp tube to one of the grid inputs of the output tube. The secondary of the driver transformer will do the phase inversion.

Clifton

:This set has an open circuit primary on the audio driver transformer.
:Does anyone know of a replacement or a workaround perhaps by just RC coupling to the output tube ?
:

:Tim,
:
:If the secondary winding is good from each end to the centertap, you could sub in around 22K resistor from plate of the amp tube to B+ and use a coupling cap of something like .1uf from the plate of the amp tube to one of the grid inputs of the output tube. The secondary of the driver transformer will do the phase inversion.
:
:Clifton
:Thanks all,
Clifton , your suggestion is one I was considering.
I have a Patterson set with this arrangement
so will give it a try.
:
::This set has an open circuit primary on the audio driver transformer.
::Does anyone know of a replacement or a workaround perhaps by just RC coupling to the output tube ?
::
:
: