NFB and Electron Propagation (from Blind Testing)

[mikek]

Originally posted by fdegrove
Hi,



It is still an error no matter how small.

Thanks to compounded small errors we miss out on fidelity which is why we should consider the error in every single component, heck, even an inch of wire or a silly fuseholder for all I care.

Cheers,

....the purpose, and indeed, the beauty of negative feedback of course, is that such 'errors', non-linearity, noise,...etc...are rendered inaudible in a well designed amp...

[Brett]

Originally posted by mikek


....the purpose, and indeed, the beauty of negative feedback of course, is that such 'errors', non-linearity, noise,...etc...are rendered inaudible in a well designed amp...

Really?

http://w3.mit.edu/cheever/www/cheever_thesis.pdf

[fdegrove]

Hi,

the purpose, and indeed, the beauty of negative feedback of course, is that such 'errors', non-linearity, noise,...etc...are rendered inaudible in a well designed amp...

No Sir, the errors are there and always will be.
What NFB does is attenuate them by a defined amount usually expressed in dB and by the same token introduce other timing related problems.

The only beauty I find in feedback is when it is applied locally, not globally and even then I remain skeptical of it.

Feeding back,

[fdegrove]

Hi,

http://w3.mit.edu/cheever/www/cheever_thesis.pdf

What took you so long Brett?

[Brett]

Originally posted by fdegrove
Hi,

http://w3.mit.edu/cheever/www/cheever_thesis.pdf

What took you so long Brett?

Been a bit under the weather.
Now I'm not, I'm going to take my bike for a spin through the mountains.
Cheers

[mikek]

Originally posted by Brett


Really?

http://w3.mit.edu/cheever/www/cheever_thesis.pdf

...correct..beautifully written thesis not withstanding....see cordell....'A MOSFET Power Amplifier with error correction', and refereces cited theroff, with regard to DIM, TIM, etc, and relationship to THD.....Note that the author of the thesis cites a zero feedback design 'cary, reviewed in stereophile, where the reviewer asserts the amp comminicates i n a way he has not experianced before....is this not the same publication that refered to the Halcro, (with substantial feedback, and error correction), as the worlds best amp.?......consistency is not the province of these publications i fear...

i take issue with this thesis from its very title...which implies that existing methods of measurement do 'not correlate' with perceived sound quality......

[mikek]

Originally posted by fdegrove
Hi,



No Sir, the errors are there and always will be.
What NFB does is attenuate them by a defined amount usually expressed in dB and by the same token introduce other timing related problems.

The only beauty I find in feedback is when it is applied locally, not globally and even then I remain skeptical of it.

Feeding back,

...What 'timing related' problems does feedback introduce?

...and on what grounds do you consider local negative feedback to be superior to its global application?

...and precisely why do you nevertheless remain sceptical of the whole shooting match...

...do'nt get me wrong, if there is something you are attempting to teach me here, i am more than willing to learn , but please be gentle.... ....i need to be taken from first principals....

[fdegrove]

Hi,

What 'timing related' problems does feedback introduce?

Error correction, no matter how fast, is always, by nature, a correction occuring after the event, in casu an error.

Hence my skepticicsm,

[Steve Eddy]

Originally posted by fdegrove
Error correction, no matter how fast, is always, by nature, a correction occuring after the event, in casu an error.

That rather describes our whole existence, doesn't it?

I mean, everything we experience we experience after the fact. Light. Sound. Never impulses. They all travel at finite speeds. We can only experience, respond and react to our surroundings as they existed in the near past, never in the present.

se

[fdegrove]

Hi,

I mean, everything we experience we experience after the fact. Light. Sound. Never impulses. They all travel at finite speeds. We can only experience, respond and react to our surroundings as they existed in the near past, never in the present.

Very good insight Steve, I'm duly impressed...
By the same token it also shows that you don't seem to grasp the fact that feedback in amplifiers is an event after the actual event , time delayed after the natural time delay?

No such thing as the present,