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Hi all I've finally got around to doing some trouble shooting on my V6 build. I have quite a bit of hum coming from my EL84s. I have did a lead dress and checked all the ground points. I have tried 3-4 different sets with no change. I also tried and set of old telefunkins I had around and one red platted quite possible the tube but it caused me to do some bias calculations. I used the BBQ calculation page and came up with some pretty high results like around 14 watts. I am currently running 150ohm cathode resistor with a 220up cap. Increasing the cathode resistor quiets the tubes and I have tried up to a 220ohm. The amp gets quieter with the 220ohm resistor but doesn't sound real good and platte voltage gets up around 380 volts. Listed below are some reading I have taken using the 150ohm resistor.

B+ 353 volts
Screen 352 volts
Platte 362 volts
Cathode 12.48 volts



Anyone have any similar problems with there builds. JGK

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JGK

You should be OK with a 150 ohm resistor on the EL84 - I see 125 in the pic which would be hot.
The 6v6 is not noisy?

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Stephen
Web: www.trinityamps.com. Facebook: facebook.com/trinityamps. Twitter: @trinityamps

Sorry its an old picture I have replaced the 125 with a 150ohm. I am getting ready to do the mods listed in your updated layout for the 6V6. I also have one of your sIII. Just can't figure out why I have the hum with the el84s. I'll se what happens after I do the conversion. JK

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JGK