Error Correction balanced in the output stage.

[Tom Schlangen]

On 09/07/2004 Patrick Turner wrote a message with exactly
this Subj. above, explaining an interesting method of, how
shall I put it, shunt FB from output stage plates to
differential inputs of a crosscoupled diff amp. Also,
Pat posted an according schematic at ABSE.

From the explanation, I could not derive if this only
was a proposal, or actually a finished amp.

So, did someone try this in vivo? Pat, maybe you yourself?

Tom

P.S.: I still have the schematic and expalantion text
somewhere, if nobody remembers I could repost (or maybe
Pat will do)

--
To err is human - to purr feline.
- R. Byrne

[Patrick Turner]

Tom Schlangen wrote:

> On 09/07/2004 Patrick Turner wrote a message with exactly
> this Subj. above, explaining an interesting method of, how
> shall I put it, shunt FB from output stage plates to
> differential inputs of a crosscoupled diff amp. Also,
> Pat posted an according schematic at ABSE.
>
> From the explanation, I could not derive if this only
> was a proposal, or actually a finished amp.
>
> So, did someone try this in vivo? Pat, maybe you yourself?
>
> Tom
>
> P.S.: I still have the schematic and expalantion text
> somewhere, if nobody remembers I could repost (or maybe
> Pat will do)

The error correction schematics posted at ABSE are most likely still
there in achives as well as
the discussions betwen me and all the disbelievers who were agast that i
had thought of
something novel and worth trying.

Take a look at
http://www.turneraudio.com.au/miscellaneous-schematics2.html
go to the schematics named 'error correction'

Use brain to analyse what is occuring.

There is a difference between error correction and NFB summing.

In a NFB amp the two amp imput ports get input signal at one input port,

and at the other port there is also a similar signal amplitude but
containing distortions.
The difference between the two signals is amplified.
With error correction there is a shunting oppositely phased signal to
the output signal generated by a separate
input tube. Thus a signal with only distortion signals is generated and
applied
to one of the imput ports of the amp, with input going to the other port

in the conventional manner.
The difference between the two is amplified, and errors corrected
similarly to NFB amps
but using less gain than usual enclosed by a FB loop.

Whether there are advantages is something you can find out; I have been
to busy
to continue past initial trials about 4 years ago or more.

Patrick Turner.


>
>
> --
> To err is human - to purr feline.
> - R. Byrne

[Tom Schlangen]

Hello Patrick,

> Take a look at
> http://www.turneraudio.com.au/miscellaneous-schematics2.html
> go to the schematics named 'error correction'

Ah, I see - overlooked that one on your homepage, sorry.

> Whether there are advantages is something you can find out;
> I have been to busy to continue past initial trials about
> 4 years ago or more.

That was the point of my question; if you didn't, maybe somebody
else has actually built a full working example.

Tom

--
Knowledge is power - knowledge shared is power lost.
-- A. Crowley

[Patrick Turner]

Tom Schlangen wrote:

> Hello Patrick,
>
> > Take a look at
> > http://www.turneraudio.com.au/miscellaneous-schematics2.html
> > go to the schematics named 'error correction'
>
> Ah, I see - overlooked that one on your homepage, sorry.
>
> > Whether there are advantages is something you can find out;
> > I have been to busy to continue past initial trials about
> > 4 years ago or more.
>
> That was the point of my question; if you didn't, maybe somebody
> else has actually built a full working example.

I don't know if anyone has bothered to try anything like this.
Guys are just too plain conservative to try anything different.

They say "Wev'e been growin potatoes thisaway for nigh on 50 years
an' we ain't a gonna try some damn fandangled nu way, OK".

Not only that, but some said that error correction was just the same as
NFB.
It is in its outcome, ie, lowering Rout, lowering N&D and increasing bw
but there is a big difference in how
the outcome is obtained.


Patrick Turner.

>
>
> Tom
>
> --
> Knowledge is power - knowledge shared is power lost.
> -- A. Crowley