• WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
    Building, troubleshooting and testing of these amplifiers should only be
    performed by someone who is thoroughly familiar with
    the safety precautions around high voltages.

rca 829b bias ? Audioromy 828

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Thank you for your respons Nick but I need a little more information.
Can I simply put another fu 29 / GU 29 / 829b tube in
the amplifier without imposing Bais on the amplifier?
Are there any who have a picture (diagram) of the amplifier?
to better see what is what?
The 4 potmeter at the bottom of the amplifier is to
making Bais, or what?
Are there any others who have modified this amp?
Or can come up with some tips
thanks in advance.

Yours Ole Slot
 
You must know how many is current plate of every old tube.
If You have some knowledge to measure I, U, R, You can
try to measure Ia /current plate/ and them adjust the same current of new tube. First, if there is cathode resistor You can measure its U.
Then put new tube, and adjust the same U with bias pot.
Or disconnect every anode and connect serial ampermetre to measure Ia. And them put new tube and adjust the same Ia with bias pot.
If there isn't bias pot. You must put new cathode resistor that
Ia=Ucathode/Rcathods. Ia old and new tube must be the sames.
Ucath resistor old and new tube must be also the sames.
 
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