einstein biasing

  • Thread starter Thread starter just42dave
  • Start date Start date
J

just42dave

Well-known member
didnt have much time to look but noticed something written bout taking fuses out while biasing on the back??
Can someone tell me how to do this easily.. I have a bias rite or just plain old multimeter...
 
If you use a BR, you don't need to pay attention to the fuses.
Pull tubes, add adaptors. put tubes into adaptors, amp on and run on.
Read mA (per TUBE !)

Set Bias (which version do you have - internal or external pot?) to the following values:

PER TUBE (thats what you are reading)
30-35mA for EL34s
 
sounds good...I have the external but if I use a multi meter do I have to remove the fuses... Sounds strange..
 
Not strange.

With a multimeter you are reading plate currents, directly where the current is going thru the multimeter (thus you have to take out the fuse)
With the BR you are reading cathode currents with a resistor (built into the adaptor) vs. ground. In fact (U = R x I) the 1 Ohm resistor reads the voltage drop which results directly into current because it is - a 1Ohm type, then U = I valuewise)
 
sounds good do you know anyone that does the 3channel mode mod??
 
Bias the current to 75mA for each pair. This is what Peter Diezel recommends for the US and this is what I have been doing.
 
You must log in or register to reply here.
Back
Top