Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: silat on June 08, 2025, 11:44:03 am
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Anyone ever use these type of transformer with success?
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Here you can find informations about the use of line transformers as Output Transformers
https://ozvalveamps.org/optrans.html (https://ozvalveamps.org/optrans.html)
Franco
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Thanks Franco! I heard you could use them , but it will take some syphering to figure it out. I have four and they are boat anchor heavy, not the big. Maybe 3 1/2" L X 3" H X 3 1/2" W.
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If nobody used one of the transformers you have as OT and report it to you, you must read the explanation on the link and then apply some of the usual math we use to investigate unknown transformers
Do you know how to proceed as to discover turn ratio and reflected impedances ?
Franco
p.s.: May be our friends TIMBO and/or Darryl are able to say something about the line transformers use
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If nobody used one of the transformers you have as OT and report it to you, you must read the explanation on the link and then apply some of the usual math we use to investigate unknown
transformers
Do you know how to proceed as to discover turn ratio and reflected impedances ?
Franco, I have been studying it. Impedance is the turn ratio squared.
Franco
p.s.: May be our friends TIMBO and/or Darryl are able to say something about the line transformers use
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Here you can find some info
https://www.radioremembered.org/outimp.htm#:~:text=The%20reflected%20impedance%20is%20a,impedance%20ratio%20of%20100%3A1 (https://www.radioremembered.org/outimp.htm#:~:text=The%20reflected%20impedance%20is%20a,impedance%20ratio%20of%20100%3A1)
Franco
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I am using one with a Rob Robinette 12AU7 self split output stage as a reverb driver. Works well. Put a speaker on it once just to check and it was really loud. But used a line tansformer that gives me 10k, 20k 30k primary and 4, 8, 16 Ohm secondary, so lots of options to get the load right.