Re: Valve question
I thought that applying HT to a valve without having the heater up to temperature was a recipe for cathode stripping and shouldn't be done. Most, if not all of the valve guitar amplifiers using a thermionic rectifier that I have seen have a standby switch that prevents HT getting to the valves. This switch has two functions; it prevents cathode-stripping on turn-on and saves a bit of power between uses of the amp. If a thermionic rectifier is used, the slow warm-up of the rectifier prevents HT being applied to the valves before their heaters have warmed sufficiently to emit electrons.
Colin.
PS. It's a rare occasion when I can offer advice to John_BS rather than asking him for some!
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