transformer amplification amplifier

wg_ski

Member
2007-10-10 5:21 pm
damianl said:
SO what i am looking for is an amplifier incorporating an audio output transformer rather than transistors? i am interested in building like this and how they sound.

I will still have transistors - just less of them. You can do a good job with just *two*. How will it sound? Probably a lot like a push pull pentode tube amp.

I've got an idea - if you use both input and output coupling transformers couldn't you just do away with the power transformer? 500 volt hexfets are cheaper than a power transformer, aren't they?
 

djk

R.I.P
2001-02-04 4:23 am
USA
"I've got an idea - if you use both input and output coupling transformers couldn't you just do away with the power transformer? 500 volt hexfets are cheaper than a power transformer, aren't they?"

The output transformer to go less than 60hz will be bigger than a 60hz power transformer, and much harder to design for the broad bandwidth required for an output transformer.
 

Vlauga

Member
2005-05-24 12:38 am
Msk
I have thought up the amplifier with the passive transformer amplifier of voltage already about fifteen years ago. Several years ago published it scheme at this forum, but nobody has paid attention)))

[IMGHTTPDEAD]http://keep4u.ru/imgs/s/080307/39/39dcba2a571a62be03.jpg[/IMGHTTPDEAD]

My amplifier since then have repeated many people. Which consider, that my amplifier sounds definitely better, than the best tube amplifiers on greater tubes like WE211.

The description how to do the amplifier is to the address of. In the end article also it is told, how most to make for it the transformer, the power supply and the device of a delay of connection of loudspeakers.


Calculation of the step-up transformer for the First stone ©Ul'yanov

The article (In Russian)))


P.S.I know, that I the genius))) And not because of this amplifier)) Because I know, whence we, people, and what for))))
 

KSTR

Member
Paid Member
2007-07-17 2:35 am
Central Berlin, Germany
I'm with you, Vlauga, I'm with you, because your schematic exactly realizes what I have proposed in post #3, in a very simple and elegant way. There are not many VAS stages easier and better than a good transformer.

Clever schematic, I like the (passively) boostrapped diamond buffer. The input "grid" choke is also very rarely seen in solid state designs, although it has many advantages.

Probably it didn't gather much attention here because of two things:
1) most solid state designers are somehow afraid of iron in the signal path,
2) it will not qualify as a "low distortion amplifier" when tested with textbook measurements.

For those interrested I babelfished the article web site:
http://72.30.186.56/babelfish/trans...ral-for.narod.ru/index/stones/first_stone.htm

- Klaus
 
Re: Re: transformer amplification amplifier

PMA said:


If it amplified a POWER, it would actually be a candidate for a Nobel prize.


Not really. Quite old stuff. Was the usual way of amplification before the invention of the triode. Lars Lundahl sold an amp called "Magamp" in the early nineties. What was new about it was the better efficiency. A simplified schematic was in an audio magazine at that time. I tried to find it again, but wasn´t successful. VAC builds magamps for stabilization of power supplies.
http://www.vacuumschmelze.com/dynam...ation/applicationknowhow/magamptechnology.php
 

Vlauga

Member
2005-05-24 12:38 am
Msk
Re: Re: Re: transformer amplification amplifier

el`Ol said:



Not really. Quite old stuff. Was the usual way of amplification before the invention of the triode. Lars Lundahl sold an amp called "Magamp" in the early nineties. What was new about it was the better efficiency. A simplified schematic was in an audio magazine at that time. I tried to find it again, but wasn´t successful. VAC builds magamps for stabilization of power supplies.
http://www.vacuumschmelze.com/dynam...ation/applicationknowhow/magamptechnology.php


It was the joke))

Hm..... All has begun with me))
 

kuznec

Member
2009-09-04 2:32 pm
no bad idea !

this is no bad idea !

Amplifiing stage without any semiconductor or tube distortion

try JFET stage(Au=1) , good transformer , and MOSFET A-class stage (Au=1) , no capacitor :O)

I try old transformer from 8:1 100V "wire" radio distribution (in Slowakai 30 years backward :O) and sound is very fast and impressive...

Kuznec