RussBert
Active Member
Any considerations when switching to EL34's from the 6550/KT88? Can I just pop them in and bias accordingly? thanks.
Yes. The bias circuit must be modified for amps that came stock with 6550's to run EL-34's
Any considerations when switching to EL34's from the 6550/KT88? Can I just pop them in and bias accordingly? thanks.
The amplifier may be setup more for 6550.Hello, I am fighting the same issue on my '79 2204.
I have plate voltage of 405 with EL-34's. I can only bias up to about 29ma. My calcs say about 43.2 (25 divided by 405= .0617 x .7= .0432).
I have a 47k bias resistor that appears to be stock, I'm guessing I would have to lower that resistor to bias up? Any suggestions? I think I have 27k and 33k's here.
Thanks