Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: tubenit on September 14, 2025, 06:21:09 am

Title: zener diode voltage drop
Post by: tubenit on September 14, 2025, 06:21:09 am

With a power transformer without a center tap,  would both of these approaches work OK?  Don't know I'll need to drop voltage but I wanted to explore this ahead of time.


I'm wondering if an EZ81 could be used doing this when there is no PT centertap also?   


With respect, Tubenit

Title: Re: zener diode voltage drop
Post by: Merlin on September 14, 2025, 06:26:32 am

Yes that will work

Title: Re: zener diode voltage drop
Post by: tubenit on September 14, 2025, 10:51:33 am

Merlin,  thank you for your help on my posted questions and the other forum member's questions also!  Grateful that you would share your knowledge and expertise.


I'm understanding your response to mean that both schematic ideas (solid state and the tube rectification)  I posted would work.


With respect, Tubenit

Title: Re: zener diode voltage drop
Post by: TIMBO on September 14, 2025, 02:48:39 pm

Hey mate, Both will work.
The tube rectifier will drop more in voltage than the SS.

Title: Re: zener diode voltage drop
Post by: kagliostro on September 14, 2025, 04:01:22 pm

Yes, with the Vacuum Tube rectifier the drop will be more than if using a SS FWB but always the presence of the zener will drop 25v more than of It wasn't present

Franco