Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: ok_state_blues on December 20, 2021, 07:48:52 pm

Title: 5V out of phase for bucking
Post by: ok_state_blues on December 20, 2021, 07:48:52 pm

Has anybody ever tried this?

http://www.diytube.com/phpBB2/viewtopic.php?t=3023

I have been trying to find a way to lower secondary voltages on organ transformers being repurposed and have never heard of such a thing. It seems like if you are willing to give up the 5 volt tap, a lot more of these transformers could get a second life.

For those not looking to open the link, check the screen shot.

Title: Re: 5V out of phase for bucking
Post by: sluckey on December 20, 2021, 08:24:43 pm

I do it like this. See page 2...

     http://sluckeyamps.com/misc/Amp_Scrapbook.pdf

Title: Re: 5V out of phase for bucking
Post by: ok_state_blues on December 20, 2021, 08:54:30 pm

Quote from: sluckey on December 20, 2021, 08:24:43 pm

I do it like this. See page 2...

     http://sluckeyamps.com/misc/Amp_Scrapbook.pdf

I placed my order for a similar set up just the other day. Would this be preferential to my previously stated method?

Just as a side note, I am using the PT from an AO-14 chassis for a 5F4 hybrid. The PT ffom the organ should be 380-0-380, so I thought this would help me shave a few off the B+

Title: Re: 5V out of phase for bucking
Post by: sluckey on December 20, 2021, 10:24:40 pm

Using the 5V winding to buck your AC primary voltage down may not lower your B+ enough to compensate for the increased B+ resulting from now having to use a SS rectifier.

I prefer to have a separate bucking unit that I can use on any amp. Your preferences may be different.