New Doug Self pre-amp design...

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using MS excel2003
 
Got it. Thanks.
I have three strange straight lines on the output noise graph. Are those the issues you mentioned?

I tried to do a noise analysis in excel many years ago. I gave up, I just didn't know enough to get sensible answers from the sheet.

Exactly. The straight lines are all superfluous and the valid curves are all defined by their respective point values.
 
but do you know the basics for “just hearing” it rather than using the rest of your brain - Double Blind isn't just for Academia – it is a fundamental requirement in any sensory testing

Psychoacoustics has some additional requirements established of many decades of experimentation

level matching to better than 1%, rapid switching to use short term memory gives much higher resolution in Double Blind AB/X test
there are several classic ways AB switching can "leak" information: relay noise, delay, noise floor differences

No one can just decide to be “mentally honest”, “suppress expectation bias” or have high resloution when "I heard it yesterday, last week, or at a show..." - that is a comic book super hero view of human perception
 
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but do you know the basics for “just hearing” it rather than using the rest of your brain - Double Blind isn't just for Academia – it is a fundamental requirement in any sensory testing

Psychoacoustics has some additional requirements established of many decades of experimentation

level matching to better than 1%, rapid switching to use short term memory gives much higher resolution in Double Blind AB/X test
there are several classic ways AB switching can "leak" information: relay noise, delay, noise floor differences

No one can just decide to be “mentally honest”, “suppress expectation bias” or have high resloution when "I heard it yesterday, last week, or at a show..." - that is a comic book super hero view of human perception

So OPA 827 doesn't sound better than NE5532 then:confused:
 
only that naive "just listen" sighted, slow swapping is poor evidence - and is the "method" overwhelmingly promoted by popular audiophile press, reviewers


I can imagine circuits, loads that could show audible differences - would amount to misapplication of one of the op amps - the OPA827 does have better specs overall, the extra speed could cause problems in circuits that the slower 5532 is safe in
 
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only that naive "just listen" sighted, slow swapping is poor evidence - and is the "method" overwhelmingly promoted by popular audiophile press, reviewers

I can imagine circuits, loads that could show audible differences - would amount to misapplication of one of the op amps
I'm sorry, it must be me but I don't understand a lot of what you write.
I just know what I like, that is the purpose of my "HI-FI":)
 
So OPA 827 doesn't sound better than NE5532 then:confused:

................that could show audible differences - would amount to misapplication of one of the op amps -.............
the output will depend on which, or any, or both are misbehaving in the circuit under test.

That is the fundamental requirement for any comparison. Both opamps must be properly fed and loaded to ensure they perform to specification.
 
It can sound different, I agree.
It should represent the original, that's what I want. Otherwise, High Fidelity can never be achieved.

I don't want a corrupted sound, I want Fidelity.

Hi Andrew, when I first started out on my high fidelity journey, I too wanted fidelity.

Had all the gear that could have done it from the Linn camp to the Quad camp.

Then CD was invented, I was one of the first in my town to own a cd player Sony cdp101. A saviour I thought High fidelity is mine.:)

But as the years go by it dawns that every single piece of equipment sounds different and therefore fidelity is just an aspiration.
The very best that you can hope for is getting a sound you really like and be happy with day to day. Bliss is probably the best word.
But don't think that it represents fidelity because as soon as you hear a live brass instrument or drum kit, you will be disappointed.
 
Hi Andrew, I do understand really, It's just that I do know what sounds better in my system, night and day sometimes.
All this gobbledegook mumbo jumbo often gets in the way of the music.

If it sounds good to you then it is, simple.:) Enjoy the music:)

The problem is amplifiers can be made to oscillate and do other bad things, you were'nt around the time I related the story about a friends amplifer oscillating at 60MHz with exotic cables and he said it didn't matter because no one can hear that. You can just ignore all technical matters if you wish, it's all for the propeller heads after all.