I'm reading DC coupling in tube based guitar amplifiers and how avoiding capacitors in the signal chain reduces signal loss, phase distortion, and noise introduction from the resistors that also have to be brought in.
The topic is fascinating, but there's an upper limitation on how many times one can DC Couple gain stages, mainly to due to the maximum cathode-heater voltage. Most tubes are 100v, others are 180v.
The heaters on tubes don't care if they're ran by DC or AC (AC is probably better if the filaments are in series).
If my initial power source is 24vdc, is there a prebuilt module that can kick out 12.6vac/vdc, or 6.3vac/vdc at high amperage? Everything I'm finding is like $100+. It seems like if you have a sine wave generator drive a transformer, one could make a simple DC-AC isolated converter. It seems like an idea so simple, but I cannot find anything like this, so I'm wondering if there's a specific term I need to be searching for, or if there's a design I could use to build my own.