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09-22-2021, 03:30 PM
Hi guys,
to cut along story short, I have a PA-10 with two boards, each with a pair of tubes. A PA-66 with two EL34s and a PX-66 (actually a cut PA-66) that carries two 6L6s. I regularly use either EL34s or 6L6s. Since there is a lot of heat under the hood, I would like to turn off the pair I don’t use while playing through the other one. I'm not talking about muting, rather about powering on/off.
In TUT, p. 6-57 there is a paragraph on Cathode switching as a stand-by for power tubes. Is this the best way to reduce heat? I am thinking about a solution that completely turns off either the EL34 or the 6L6 pair if technically possible.
Is there any mechanical switching that would turn off the B+ plate supply and the heater feed at a time between PSU-PA and PA-66 respectively PX-66? Maybe anything better?
Unfortunately, most DPDT switches can only handle DC voltage up to 250V. B+ plate supply usually is much higher. The heater feed can easily be broken. It is 12 V from the power supply.
Can anybody help me with this issue?
Best wishes
Kai
to cut along story short, I have a PA-10 with two boards, each with a pair of tubes. A PA-66 with two EL34s and a PX-66 (actually a cut PA-66) that carries two 6L6s. I regularly use either EL34s or 6L6s. Since there is a lot of heat under the hood, I would like to turn off the pair I don’t use while playing through the other one. I'm not talking about muting, rather about powering on/off.
In TUT, p. 6-57 there is a paragraph on Cathode switching as a stand-by for power tubes. Is this the best way to reduce heat? I am thinking about a solution that completely turns off either the EL34 or the 6L6 pair if technically possible.
Is there any mechanical switching that would turn off the B+ plate supply and the heater feed at a time between PSU-PA and PA-66 respectively PX-66? Maybe anything better?
Unfortunately, most DPDT switches can only handle DC voltage up to 250V. B+ plate supply usually is much higher. The heater feed can easily be broken. It is 12 V from the power supply.
Can anybody help me with this issue?
Best wishes
Kai
