• 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.

Heater current draw question.

I am working on a pp am build, parts gathering and circuit decisions.
I my power transformer rectifier heater winding is rated at 2 ma and the rectifier I would like to use has 1.8 ma draw per data sheet, am I stretching things with this load?
Or if rated at 2ma it's good at 2ma?
 
Just wondering what rectifier?
The closest I could think of would be a GZ34/5AR4 having a heater current of 1.9A.
In any case if it's a 5V heater, be aware the the heater winding will be floating on B+, so must not be connected to anything else.
 
6d22s.
Just re looked at the data sheet.
1.9 amps
Separate windings for tubes vs rectifier.
The 6D22S was originally a tv damper with 6.3V indirect heaters.
https://frank.pocnet.net/sheets/164/6/6D22Sspec.pdf
The datasheet even allows heaters common with other tubes up to 600V B+.

Remember, the top cap is the cathode and goes to B+.

Also you should be aware that a single 6D22S is only a half wave rectifier.
In which case you get DC in your HV transformer winding which will saturate it's core and cause it to overheat grossly.

For a full wave setup you need at least a second 6D22S tube and a center tapped B+ winding.
And another 1.9A of heater current, so a total of 3.8A ...
 
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So I'm am using 1 half wave rectifier tube and two diodes forming a center tap.
Bright is the wrong term?
Just a hybrid rectifier? 20250127_143927.jpg
 
The tube in the picture is not a half wave rectifier.
It has 2 plates, two diodes with common cathode in one bottle.
That works.
But both 6AU4 and 6D22S have only one plate.
For your hybrid bridge you either need 2 tubes with one plate each
or a single rectifier tube with 2 plates ...
 
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