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Dual bias pots for Fender

12/17/2000 4:51 PM
Firefly
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Dual bias pots for Fender
When changing from sible to dual bias pots in a standard blackface fender amp, What do you do? How do you calculate the part values? Has anyone drawn this up alreday?  
 
 
 
You'd have to separate the two 220k resistors and feed each to an individual pot. each pot has to be hooked up to the bias supply on one end, the wiper goes to the resistor feeding the tube , and the third lug of each pot is grounded via a resistor.  
 
 
 
Does that sound right??  
 
 
 
How do I calculate the values for the pots and resistors? Does the small 25uf@50v cap change?  
 
 
 
Thanks, Firefly

 
Replies:
Tim Gagan Hi Firefly,Your des... -- 12/17/2000 5:33 PM