Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: 6v6Pin1 on September 13, 2015, 12:13:48 am

Title: EL84 voltages
Post by: 6v6Pin1 on September 13, 2015, 12:13:48 am
I changed the rectifier in my stout which increased B+ quite a bit.
I measure 342v on the plate and 12v across the 130ohm cathode resistor.
((12 / 130) / 2) * (342 - 12) = 15.2 watts.
Am I going to blow up my EL84s? Should I be Ok running my amp like this? Which voltages should I be targeting in this amp?

The schematic on here for the stout project shows
((11.2 / 130) / 2) * (340 - 11.2) = 14.2 watts which I assume will work out because it's how the amp is designed, and I'm not too far over that.

Thank you.
Title: Re: EL84 voltages
Post by: PRR on September 13, 2015, 01:10:40 am
> Am I going to blow up my EL84s?

Not quickly.

And EL84 are cheap.

And so many guitar amps have over-abused so many EL84s that I bet most new-made guitar-market EL84s can stand it fine.