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Some considerations using ballpark numbers:
With the Showman PT and SS rectifier the power tube plate supply voltage for the 4x6L6 at full output may be a little higher than in the original amp, let's assume +10%. Using the same load impedance this means +10% max. primary signal current. As a result max. output power will increase by about 20% and OT (copper) losses will increase by around 20% as well. Even if we add say +10% increase of OT core losses, the total increase of OT dissipation will be around 2W - not critical.
What will suffer is the power tube screens, so expect reduced tube life.
Things change if the speaker load is changed to 2 Ohm. This will increase available output to maybe 70W or 75W, but also double OT primary current. Meaning that OT copper losses will increase by around a factor of 4 resulting in a total OT power dissipation of maybe 20W. Thus the OT may overheat and eventually fail.
With the Showman PT and SS rectifier the power tube plate supply voltage for the 4x6L6 at full output may be a little higher than in the original amp, let's assume +10%. Using the same load impedance this means +10% max. primary signal current. As a result max. output power will increase by about 20% and OT (copper) losses will increase by around 20% as well. Even if we add say +10% increase of OT core losses, the total increase of OT dissipation will be around 2W - not critical.
What will suffer is the power tube screens, so expect reduced tube life.
Things change if the speaker load is changed to 2 Ohm. This will increase available output to maybe 70W or 75W, but also double OT primary current. Meaning that OT copper losses will increase by around a factor of 4 resulting in a total OT power dissipation of maybe 20W. Thus the OT may overheat and eventually fail.
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