• 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.

Affordable 200mA tube rectifier

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#9
milen007 said:
I just drop with resistor for 5v right? My supply is 6.3v
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Eh ... not really. A 5V rectifier requires a dedicated winding, because the DC output rides on top of the filament voltage. Not to mention that at the current involved, a dropping resistor would burn almost 4W, and that's unnecessary heat.

If what you have is a 6.3V supply, IMO you should really only consider 6.3V rectifiers.
 
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#11
deafen said:
Eh ... not really. A 5V rectifier requires a dedicated winding, because the DC output rides on top of the filament voltage. Not to mention that at the current involved, a dropping resistor would burn almost 4W, and that's unnecessary heat.

If what you have is a 6.3V supply, IMO you should really only consider 6.3V rectifiers.
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That’s a terrible idea. The heaters should be referenced to ground or slightly above. Now you’re relying in the heater cathode rating of the rectifier.
 
#14
astouffer said:
That’s a terrible idea. The heaters should be referenced to ground or slightly above. Now you’re relying in the heater cathode rating of the rectifier.
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When running the heaters at B+ level (which is the case with the 5V octal rectifiers like 5U4, GZ34 etc) you are relying on the isolation of the (dedicated) transformer winding. Make sure it's up to the task.
The EZ81 tube has a heater-kathode rating of 500V (kathode positive), and can be run from a grounded 6,3V heater winding. You can even share the 6,3V with the rest of the tubes.
The EZ81 can supply up to 150mA.
 
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#15
Parafeed813 said:
When running the heaters at B+ level (which is the case with the 5V octal rectifiers like 5U4, GZ34 etc) you are relying on the isolation of the (dedicated) transformer winding. Make sure it's up to the task.
The EZ81 tube has a heater-kathode rating of 500V (kathode positive), and can be run from a grounded 6,3V heater winding. You can even share the 6,3V with the rest of the tubes.
The EZ81 can supply up to 150mA.
Click to expand...
Superb. Thanks alot. Great suggestion. Available locally and affordable. Niceeee
 
#16
milen007 said:
Ada schematic that do that? Thx
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1660809840400.png
 
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