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Old 2nd September 2009, 11:15 PM   #1
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Default Triode connected Pentodes in a cathode bias?

I have a Crate V3112 with 4-el84's. I was thinking about doing this for that amp. I've read that the plate volts can be bad for the screens, but I've measured only about 4 volts difference between them on this amp, so I don't see what the problem is.

I would connect them with the 100 ohm screen resistor in the middle.

What do you think?
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Old 2nd September 2009, 11:31 PM   #2
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What's the B+ supply to the plates?
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Old 2nd September 2009, 11:38 PM   #3
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What's the B+ supply to the plates?
328-333 volts depending on the time of day.
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Old 3rd September 2009, 12:30 PM   #4
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300 is the limit for the EL84 screens. I wouldn't try it myself.
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Old 3rd September 2009, 10:11 PM   #5
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Quote:
Originally Posted by leadfootdriver View Post
I have a Crate V3112 with 4-el84's. I was thinking about doing this for that amp. I've read that the plate volts can be bad for the screens, but I've measured only about 4 volts difference between them on this amp, so I don't see what the problem is.

I would connect them with the 100 ohm screen resistor in the middle.

What do you think?
With 100R screen resistors that is fine. Many people have done it. As you point out, there is hardly any difference in voltage in either mode.
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