Bias Question- 1979 JMP Mk2 Master Volume (2203)

gbmojo

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Hi All!

The last time I had my amp serviced, the tech said that he replaced the bias resistor to accomodate EL34's (electro harmonix). The tubes failed fairly quickly. I'm about to replace them with a set of GTel34m's, and when I checked thye fixed resistor installed, it looks like a 10K. While a pair of the EH tubes still worked, I hooked up my Bias-Rite meter and had to turn the vari-resistor all the way down to come close to proper current (@37-40ma).

I'm wondering if the right bias resistor is installed. Does anyone know what the proper value resistor is for EL34's on a 2203?

Thanks everyone!

GreggB.
 


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