Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => AmpTools/Tech Tips => Topic started by: Miyagi_83 on November 07, 2023, 07:00:49 am

Title: Secondary windings in series for tube rectifier
Post by: Miyagi_83 on November 07, 2023, 07:00:49 am
Hello everyone,
I'm going to build an amp and I'd like to use a tube rectifier this time. The transformer I'd like to use, however, doesn't have a center tap BUT it has two separate high voltage secondary windings of the same ratings. My question is, can I connect them in series and use the connection as the center tap as in the drawing?
If the topic has already been covered, I apologize. Perhaps my search skills need working on.
Thanks in advance for the help.
Miyagi_83
Title: Re: Secondary windings in series for tube rectifier
Post by: pdf64 on November 07, 2023, 07:39:37 am

can I connect them in series and use the connection as the center tap as in the drawing?

Yes :)
How are you thinking of powering the rectifier’s heater?
Title: Re: Secondary windings in series for tube rectifier
Post by: Miyagi_83 on November 07, 2023, 07:48:16 am
Thanks for the reply pdf64. I want to use a 6X4 or an EZ80 so I was going to connect the rectifier's filament to the 6.3 V winding.
Title: Re: Secondary windings in series for tube rectifier
Post by: pdf64 on November 07, 2023, 09:07:48 am
Ok.
As the transformer probably hasn’t been specifically designed for this application, it probably won’t have sufficient protecting resistance in series with the rectifier anodes.
So that should be checked and additional resistors adding, as necessary.
See https://tubedata.altanatubes.com.br/sheets/030/e/EZ80.pdf
Title: Re: Secondary windings in series for tube rectifier
Post by: Miyagi_83 on November 07, 2023, 09:13:37 am
Ok.
As the transformer probably hasn’t been specifically designed for this application, it probably won’t have sufficient protecting resistance in series with the rectifier anodes.
So that should be checked and additional resistors adding, as necessary.
See https://tubedata.altanatubes.com.br/sheets/030/e/EZ80.pdf

Thanks for the heads up. I will definitely take that into account.