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#1 Fully balanced amplification system?

Posted: Thu Jul 04, 2019 7:31 pm
by gdog
Is it possible to implement a fully balanced amplification system -where the cartridge output is split in half with a potential divider and all subsequent stages are singled ended only meeting as push-pull in the final output transformer? Is this a bad idea? If so why?

#2 Re: Fully balanced amplification system?

Posted: Thu Jul 04, 2019 7:40 pm
by Nick
Its possible, a cartridge is inherently balanced anyway if both outputs are floating. It would be normal though to let each stage retain the balance by seeing the other half as a long tailed pair.

#3 Re: Fully balanced amplification system?

Posted: Thu Jul 04, 2019 8:01 pm
by gdog
Interesting, reading this forum I see that transformers are a little out of vogue :D , but do you think its possible that such a topology could have the strengths of a SET but with the power and range of a good PP? Better for example than a parallel SE output stage?

#4 Re: Fully balanced amplification system?

Posted: Thu Jul 04, 2019 8:11 pm
by gdog
I suppose really the LTP is a phase inverter so in essence which every way you cut it this is a PP design

#5 Re: Fully balanced amplification system?

Posted: Thu Jul 04, 2019 11:50 pm
by Nick
Well, a LTP can be used as a phase splitter, but if fed with a balanced signal, its just a balanced amplifier.
but do you think its possible that such a topology could have the strengths of a SET but with the power and range of a good PP? Better for example than a parallel SE output stage?
Maybe, but without being awkward, you may have to say what you view strengths and weaknesses of single ended and push pull, as I find its never as clear as once I would have thought.

#6 Re: Fully balanced amplification system?

Posted: Fri Jul 05, 2019 1:22 pm
by izzy wizzy
Nick wrote: Thu Jul 04, 2019 11:50 pm Maybe, but without being awkward, you may have to say what you view strengths and weaknesses of single ended and push pull, as I find its never as clear as once I would have thought.
For sure. So much material and detail to be mined from such a simple statement.

Cheers,
Stephen

#7 Re: Fully balanced amplification system?

Posted: Fri Jul 05, 2019 3:19 pm
by IslandPink
Best PP amp I ever heard was Gary Pimm's Tabor amp with the 1624 valves. That was IDHP > DHP push-pull with direct coupling & stacked power supplies. Stunning speed, transparency and great tonal colour.

#8 Re: Fully balanced amplification system?

Posted: Fri Jul 05, 2019 3:54 pm
by gdog
I have a rather limited experience of different amplifiers. I am not a constant tweaker, rather I am seeking an end-state system, which is good enough for me to forget about.

Currently I have a WD phono and KT88 amplifier sitting between my newly acquired 401 and my Tannoy Kensingtons. The speakers and the turntable are done, they are simply everything I will ever want. My digital is also done.

I do think that the amplifier could eventually be replaced however, I’m just not sure with what I can either build or acquire. I am musing over the various topologies; I had a SET in my system once and like all the expectations it had a wonderful detail mid-range with instruments and voices floating in the air but didn’t really have low end control. I listen to a wide variety of music including big orchestras which means that bottom end detail and drive are essential characteristics for any candidate amplifier.

#9 Re: Fully balanced amplification system?

Posted: Fri Jul 05, 2019 4:14 pm
by steve s
gdog wrote: Fri Jul 05, 2019 3:54 pm I had a SET in my system once and like all the expectations it had a wonderful detail mid-range with instruments and voices floating in the air but didn’t really have low end control. I listen to a wide variety of music including big orchestras which means that bottom end detail and drive are essential characteristics for any candidate amplifier.
You had the wrong single ended amp .

In the nineties a local hifi shop let me take home 3 or 4 single ended amps
Most where rejected on account of the bass performance. I eventually bought a 'simply 845' amp. But that lasted only a few months in my system due to the heat/ 1000volts/ poor sound
I think my system plays everything now... 5 watts se and 100+db speakers.