How much reduction in hum can be expected through DC-elevation of the heater supply? Let's say, in an Fender Deluxe Reverb AB763, using ~80 volts DC connected to the heater winding center tap.
Probably not noticeable unless a heater cathode is leaky. Balancing the output valves will reduce the hum.
Anywhere from zero to noticeable. Depends on the amp. Elevating heaters ONLY helps against hum due to heater-cathode coupling. If you amp doesn't exhibit that, then it won't help.
There are a hundred sources of hum in amps, and each has its own cure. Hum is not generic. If you have weak filters, elevating heaters will do nothing for it, and if you have heater/cathode problems, adding more filter caps to B+ will have no effect.
There are a hundred sources of hum in amps, and each has its own cure. Hum is not generic. If you have weak filters, elevating heaters will do nothing for it, and if you have heater/cathode problems, adding more filter caps to B+ will have no effect.
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