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Rolling (replacing) Op-amps in Topping D10 DAC

JohnYang1997

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And you know you're not stupid so that's the proof you're not imaging these, right? I admire your logic. :facepalm:
I heard the difference so i tried more. Is that not logical to you? Why would i buy more if i don't hear difference. Also if I can't hear the difference i could use cheaper parts in the final project. That's the best scenario. But it turned out to be the opposite. There were difference.
 

Krunok

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I heard the difference so i tried more. Is that not logical to you? Why would i buy more if i don't hear difference. Also if I can't hear the difference i could use cheaper parts in the final project. That's the best scenario. But it turned out to be the opposite. There were difference.
Did it ever occured to you that you're imagining you're hearing the difference?
 

JohnYang1997

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You could or you did?

If both implementations have perfectly flat frequency responce and THD+N below audibility, hearing a clear difference in a blind test would be very mysterious to say the least.
One thing to notice is that, do you think since the distortion measurements are below "audibility" you can't hear a difference? Have you ever tried different dacs or amps? No matter which is better there are very big of differences between them. And all of the dac /amps I have tried all have sub 0.002% thd and imd. They sound very different from each other.
One example is that musiland mu2p and db magix ac3 dongles. They can be used as dac. Channel separation are around -120db better than -110db. Distortion are below 0.0003%. but they sound very very very different. Mu2p sounds think splashy and can be too bright where db magix ac3 has very smooth even rolled off sounding highs and it has strange soundstage with vocal has really realistic imaging. The both have very good multitone distortion measurements. Only where I see difference is square wave. Very different.
 

JohnYang1997

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Did it ever occured to you that you're imagining you're hearing the difference?
Before all if this. I thought njm5534dd is the best opamp. And good enough for all applications for human hearing. When I experience it i realized it's not that easy.
Also in 2016(long before the project) i did tried swaping opamps. At that time i didn't measure and didn't know much about electronic. I tried opa827(could be fake more like opa604), opa1612(could be fake too) and 49990(again could be fake).
Opa827 sounds rounded just like people described opa604.
Opa1612 sounded wrong it has honky mids and elevated unnatural highs.
49990 sounded grainy and dirty in the highs.
I could have got fake ones. But they indeed sound very different. Much more different than I can hear now. I don't know if that's because my ear degrades or some other things happened.
The amp used has been the same one violectric v200. from 2016 to 2018. And later on i used o2 as platform thats performed measurements on. I only briefly listen and didn't do blind test anymore.
 

Krunok

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Only where I see difference is square wave. Very different.
According to a guy named Fourier that difference would be due to difference in very high harmonics, probably above 50kHz, and you certainly can't hear that.

Every once in a while a guy like you comes to this forum, obviously by accident, claiming that he has super hearing that would put even Superman to shame. And each time I begin to hope that the guy can't possibly think he's hearing something that can't be measured but instead he's high on some fine new stuff which he would hopefully reveal how it is called and where to buy it. Unfrtunately, each and every time my hope fails me, and something is telling me this time it won't be different either. Pity.

But ok, maybe next time..
 
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JohnYang1997

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According to a guy name dFourier that difference would be due to difference in very high harmonics, probably above 50kHz, and you certainly can't hear that.

Every once in a while a guy like you comes to this forum, obviously by accident, claiming that he has super hearing that would put even the Superman to shame. And each time I begin to hope that the guy can't possibly think he's hearing something that can't be measured but instead he's high on some fine new stuff which he would hopefully reveal how it is called and where to buy it. Unfrtunately, each and every time my hope fails me, and something is telling me this time it won't be different either. Pity.

But ok, maybe next time..
It's not that it can't be measured. There are a lot of things different in different measurements. But not frequency response. Plus it's the interpretation of some measurements not the measurements itself. Also my friends all share the same experience as mine. Especially recently db magix ac3 and musiland mu2p. If you don't believe me, try them for yourself.
 

JohnYang1997

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And btw many phones can drive 32 ohm at 0.003% thd at least under 0.01%. (more than 10 tested) Stick with the phone boy. Smh.
 

SIY

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If the answer is yes. Then there is no way on earth in a million years i would trust anything you say.
Now there is an open-minded approach to evaluation.

Is is possible your difference is real? Sure. Actual evidence would show that- anecdote is no better than the person who swears that Ricky Jay was dealing off the top of the deck. Evidence like controlled listening tests, measurement differences above reasonable audible levels, measurements of stability (a BIG issue in hobbyist op-amp swapping).

Is it far more likely that your brain is lying to you? Absolutely. In science, we start with the most likely hypotheses and work from there. You haven't addressed that.
 

Killingbeans

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One thing to notice is that, do you think since the distortion measurements are below "audibility" you can't hear a difference?
Yes.

This forum is littered with evidence pointing to the conclusion that any two DACs/headphone amps with reasonably low THD+N, flat frequency responce and similar output impedance will sound exactly the same when the output levels are matched.

Have you ever tried different dacs or amps? No matter which is better there are very big of differences between them. And all of the dac /amps I have tried all have sub 0.002% thd and imd. They sound very different from each other.
I just find it hard to believe. That's why I'm asking for a detailed description of your testing method and some hard data from measurements.
 

JohnYang1997

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Did you measure the frequency response and THD+N from all of these combinations?
Thd and noise are different. Not much. I don't think that's the source of all the difference. (it can be) Again the difference are generally very small. opamp rolling makes less difference than changing circuit. And in different circuits, i believe there maybe different sound change.(well there actually is) the sound change on the o2 later on is different than on v200. Not only because o2 uses opamp as driving stage. Also because the low resistance all the way in the signal path.
 

JohnYang1997

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Now there is an open-minded approach to evaluation.

Is is possible your difference is real? Sure. Actual evidence would show that- anecdote is no better than the person who swears that Ricky Jay was dealing off the top of the deck. Evidence like controlled listening tests, measurement differences above reasonable audible levels, measurements of stability (a BIG issue in hobbyist op-amp swapping).

Is it far more likely that your brain is lying to you? Absolutely. In science, we start with the most likely hypotheses and work from there. You haven't addressed that.
Do you agree that two amps or two dac sound different even when the thd imd noise multitone are reasonably low?
There was a guy in this forum the other day swear v200 has more body than thx789. And he really wants it on thx789. There is no way that he biased on v200. And from what i learned, it's the power supply noise creeping in the sound(not directly audible but will affect the sound) And the power supply noise is under -110dbu. Also the distortion is less than 0.001% under any load over 16 ohm. And can go down to 0.0001% for higher impedance load. I also hear difference between burson cv2+, v200, o2, jds el amp, db magix ac3 and musiland mu2p.
Also once on the show, i paired three amps with final d8000 prototype. Wa33, 430had, burson cv2+ also sp1000(isn't really an amp). Wa33 sounds like shit, 430had is much better but still plasticy sound and a bit sharp, with burson it's sounds very smooth and controled. I later on measured cv2, distortion is flat 0.002% across the frequency range. And i used hifiman he560 on burson, musiland 06p and phone output. Burson sounds colored but no 4khz issue. 06p emphasis the 4k issue sounds dry and grainy. Phone sounds soft but not too bad sounding.
I can go on and on. Opamps do make a lot less different themselves than circuits/amp/dac. But if one say he hear no difference between good measured amps and dacs? That guy must be deaf.
 

SIY

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Do you agree that two amps or two dac sound different even when the thd imd noise multitone are reasonably low?
Only if you've done a double blind level matched test demonstrating that, assuming both have flat frequency response.
 

Killingbeans

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It's really something. Especially when I changed all the opamps into opa827 the bass became just more prominent and overall warmer and smoother.
Again the difference are generally very small. opamp rolling makes less difference than changing circuit.
Those two statements just clash in my head. Sorry if I'm being cheeky, but is it "really something" or "very small"?

Are we talking something so small that it's hard to tell whether it's fantasy or not, or something that should clearly be evident in measurements?

You still haven't convinced me that you are not talking about the former.
 

JohnYang1997

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Those two statements just clash in my head. Sorry if I'm being cheeky, but is it "really something" or "very small"?

Are we talking something so small that it's hard to tell whether it's fantasy or not, or something that should clearly be evident in measurements?

You still haven't convinced me that you are not talking about the former.
Something is in contrast to nothing. Small is actually being small. There is consistent difference but really not much. That's what i was saying. Do you feel 0.5-1db in frequency response a lot? That's the feeling of it. Though can be heard consistently but not much.
 

JohnYang1997

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cn
Those two statements just clash in my head. Sorry if I'm being cheeky, but is it "really something" or "very small"?

Are we talking something so small that it's hard to tell whether it's fantasy or not, or something that should clearly be evident in measurements?

You still haven't convinced me that you are not talking about the former.
chaging from 5532 5534 to all opa827 makes one of the most difference in all opamp combinations. Kind of like 1.5db difference. That's where especially comes from. On the other hand opa2227p sounds the closest to 5534, tiny bit smoother, can be argued to be in my mind.
 
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