Bias Circuit

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rip
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Bias Circuit

Post by rip » Sat Apr 22, 2017 12:54 pm

Hopefully, this is an easy question...

Regarding the bias circuit of a JTM45/100...can someone confirm that:

-The bias splitter resistors are 220K
-The bias supply dropping resistor is 150K
-The bias pot is 25K linear
-The bias resistor in line with the bias pot is 47K
???

The reason why I ask is because I've seen other values here and there, in particular with the bias resistor and pot...so wanted to see if someone can confirm.

Thanks
Rip

Roe
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Re: Bias Circuit

Post by Roe » Sun Apr 23, 2017 8:00 am

the 47k and 150k varies slightly. The important thing to remember is to bias the tubes correctly
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Super 100 amps: 1202-119 & 1202-84
JTM45 RS OT JTM50 JMP50 1959/2203/34/39

rip
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Posts: 567
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Re: Bias Circuit

Post by rip » Wed May 03, 2017 1:34 pm

Thank you

Seems like I'll try the nominal valves...I'll be back if I need to tweak it

Thanks
Rip

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