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Rolling (replacing) Op-amps in Topping D10 DAC

Killingbeans

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But if one say he hear no difference between good measured amps and dacs? That guy must be deaf.
Or maybe that guy just acknowledge that if a difference is faint enough to be overlooked in the light of even tiny amounts of negative bias, then it's not really worth spending time and money on.

That being said, I'm still very sceptical about the difference actually being there in the first place.
 

SIY

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Blind test, i agree. Double blind. No offense, that's the least useful thing in audio.
For make-believe, sure. For actual useful data, double blind and level matched is the most basic control. Don't do that and your evidence is of the same quality as reports of alien abductions with anal probing.
 

JohnYang1997

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For make-believe, sure. For actual useful data, double blind and level matched is the most basic control. Don't do that and your evidence is of the same quality as reports of alien abductions with anal probing.
Ok. I'll try to do it. So just double blind test to dacs that measure 0.0003% thd -110db multitone residue and flat response counts right? Or maybe double blind test 5534 to opa827 counts right? That is relatively easy.
 

JohnYang1997

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Or maybe that guy just acknowledge that if a difference is faint enough to be overlooked in the light of even tiny amounts of negative bias, then it's not really worth spending time and money on.

That being said, I'm still very sceptical about the difference actually being there in the first place.
dac/ amp sound much more different than opamp rolling. Even changing a resistor value or low resistance pot will make more difference than opamp rolling. Opamp difference can be overlooked i agree thats why many pro products use jrc4580 and 5532. But the difference caused by different circuits are not.
 

SIY

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Double blind, level matched. That's the basics. And be prepared to describe EXACTLY the procedure you used to accomplish both of those. You'll want to achieve statistical significance (e.g., 95% confidence), which will vary in number of trials depending on your format.
 

Killingbeans

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Do you feel 0.5-1db in frequency response a lot? That's the feeling of it.
You feel it, but can't measure it? I'm sure you can't blame me for my scepticism.

But the difference caused by different circuits are not.
Absolutely. I'd be mad to deny that. But it's not what this thread is about.

My point is just that if something is not measurable, it's very much likely not audible either.
 
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JohnYang1997

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You feel it, but can't measure it? I'm sure you can't blame me for my scepticism.
The feel of frequency response change not always mean the frequency response is different. It can be from distortion, phase problem, ringing in square wave, noise etc. I think if you try to find a lisa3 you will know what I was talking about. That's one of the most colored sound but flat frequency response.
 

SIY

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A bit of study of the Fourier theorem might also be useful as well as the ability to do some basic measurements that will go beyond a hand-waving recitation of buzzwords used by audio "reviewers."
 

JohnYang1997

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A bit of study of the Fourier theorem might also be useful as well as the ability to do some basic measurements that will go beyond a hand-waving recitation of buzzwords.
I study electrical engineering. So do you really think I don't know fourier transform? Oh come on. Tell me 0.001% distortion will contribute how much in frequency response? And noise? Can you say this little change in frequency response make change. Oh why would you even need fft in the first place if you can measure sine sweep. Nah you don't seem legit to me.
 

JohnYang1997

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A bit of study of the Fourier theorem might also be useful as well as the ability to do some basic measurements that will go beyond a hand-waving recitation of buzzwords used by audio "reviewers."
Also i have measurements equipments. I had focusrite forte and my own pre amplifier to measure noise. cs5381 has very low low volume distortion. Distortion can go as low las -125db for each individual harmonic. -20db loop measurements showed very low distortion. Now it's broken.
I just bought a motu 828es which has ak5574 adc. When at -22db the individual harmonics are lower than 0.00003%.
 
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JohnYang1997

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Some of the old tests. I did not have the habit to name all the files. There were much more screenshots but these are the more readable ones.
 

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JohnYang1997

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i ended up using opa827 + opa2227p so the best looking one is probably opa827+opa2227p. but not sure it was april last year.
 
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