10-20-2011, 01:43 PM
Sam,
I think a Hammond universal type audio putput transformer will work for your 76. The only question is the best power rating needed. Maybe someone else with more knowledge of this model will know what the P-P 45's are capable of wattage wise. I suspect it may be only 5-6 watts audio power because of the single 27 driver tube. But I may be wrong as 45's in push-pull with the fixed bias AB2 operation is capable of a lot of power...up to 15-18 watts with sufficient drive power.
The plate to plate ideal load impedance is theoritically around 3200 ohms for this bias operation...quite low. By using the chart supplied with the transformer you can wire the secondary to get a pretty good match between the low secondary of 1.5 ohms or less to about 3200 primary impedance or so ohms. So do you need a 125 B,C,D or E transformer?
: 
Best of luck. John
I think a Hammond universal type audio putput transformer will work for your 76. The only question is the best power rating needed. Maybe someone else with more knowledge of this model will know what the P-P 45's are capable of wattage wise. I suspect it may be only 5-6 watts audio power because of the single 27 driver tube. But I may be wrong as 45's in push-pull with the fixed bias AB2 operation is capable of a lot of power...up to 15-18 watts with sufficient drive power.
The plate to plate ideal load impedance is theoritically around 3200 ohms for this bias operation...quite low. By using the chart supplied with the transformer you can wire the secondary to get a pretty good match between the low secondary of 1.5 ohms or less to about 3200 primary impedance or so ohms. So do you need a 125 B,C,D or E transformer?
: Best of luck. John
