Tube amp build (s)

[JohnH]

Yeah, it sounds great. I was playing it when I noticed the red glow and assumed I'd wired something wrong

[DrNomis_44]

Yeah, it sounds great. I was playing it when I noticed the red glow and assumed I'd wired something wrong

Was there a loud hum with the red glow?, if so, that would indicate red-plating, red-plating is usually caused by a leaky coupling capacitor on the grid of the power tube, or a loss of the -V bias supply, or sometimes by the power tube itself if it has an internal fault.


https://www.ampvalves.co.uk/red-plat...lifier-valves/


But, if the amp is sounding really good especially if you crank it up, it should be fine.


Note that some high-power radio transmitter tubes are deliberately designed to be operated in a condition where they are red-plating.