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RE: Please don't start this nonsense again

76.90.100.230

Tre'

In Reply to: RE: Please don't start this nonsense again posted by sony6060 on August 24, 2023 at 19:07:50

"where is my apology for the 5U4GB tube capacitor" Rod ended that discussion. You remember Rod, don't you? He owns this website. I don't think it is smart of you to bring that back up.

The dyna gets 32 of 33.56 volts of it's bias from the negative supply and only 1.56 from the resistor in the cathode circuit. The resistor in the cathode circuit of the dyna 70 should not be thought of as a cathode bias resistor at all. It is just there so we can measure the voltage and calculate the idle current.

What about the Fender amp with no resistor at all in the cathode circuit?
I really think that proves that your statement is false.

Tre'
Have Fun and Enjoy the Music
"Still Working the Problem"

Follow Ups:

RE: Please don't start this nonsense again - sony6060 19:16:20 08/24/23 (2)
I take the apology here Tre as you gave none before the posts was closed.
Now here this- cathode resistors are used just measuring cathode current. Nonsense Tre.

Edits: 08/24/23
- RE: Please don't start this nonsense again - Tre' 20:38:21 08/24/23 (1)
  "Now here this- cathode resistors are used just measuring cathode current."
  
  A large value resistor in the cathode circuit intended to provide the bias voltage for the tube is there for that purpose and is called a cathode bias resistor. In a circuit using cathode biasing (self bias, auto bias) there is no negative bias power supply as it is not needed.
  
  The small value resistor, found in the cathode circuit of a tube that is using fixed bias (a negative voltage provided by a negative voltage power supply dedicated to biasing the tube), is there for the purpose of measurements.......yes. That is correct. It IS a resistor in the cathode circuit but it is NOT called a cathode bias resistor because that is not it's job. It is sometimes called a "sensing resistor".
  
  Tre'
  
  Have Fun and Enjoy the Music
  "Still Working the Problem"
  - Shunt vs Biasing R - PakProtector 18:34:46 09/02/23 (0)
    We use resistors to measure current all the time. Shunts they're called. Usually measured in the tens of mV for hundreds of amps. With tube circuits it is more like 1V/100 mA... :)
    
    Douglas
    
    Friend, I would not hurt thee for the world...but thou art standing where I am about to shoot.

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