Marshall Amp Forum - View Single Post

harp · 06-24-2009, 09:03 PM

Hey Guys,
Thanks for all the helpful input. I'm still trying to figure out what's going on. I'm getting 470 volts plate voltage. Bias voltage at pin 5 is 40 volts, with tubes not installed. I've set the bias current is 15 ma (31.5 mv volts across 1 ohm resistor on between ground and pin 8)

It sounds great but after 15 minutes of playing, or just sitting there turned on, the face panel gets almost too hot to touch.

Still looking for any clues, and I'm still not real sure what too look for.

06-24-2009, 09:03 PM	#15 (permalink)
harp Junior Member Join Date: Jun 2009 Posts: 18	Re: JCM 900 6l6 to EL34 Conversion problems Hey Guys, Thanks for all the helpful input. I'm still trying to figure out what's going on. I'm getting 470 volts plate voltage. Bias voltage at pin 5 is 40 volts, with tubes not installed. I've set the bias current is 15 ma (31.5 mv volts across 1 ohm resistor on between ground and pin 8) It sounds great but after 15 minutes of playing, or just sitting there turned on, the face panel gets almost too hot to touch. Still looking for any clues, and I'm still not real sure what too look for.