Does Op-amp Rolling Work?

[Ropeburn]

"They're not looking at everything else that is involved in how those things are made, because what they're doing is they're basically a voltage stepping device.
They're stepping up voltage. So it's adding gain. So there's opportunity there for a lot of things to happen and a lot of ways to change the way it sounds,
by the way it's adding that gain and the quality of everything in the path."
...

TIL: In Danny's castle high in the skies, step up converters and amplifiers are one and the same.

He's 1) a self-claimed electronics expert and 2) a native English speaker. Turns out he fails at both. Back to engineering class 1st month!

This is a case of morbid fascination: it's so horrible, you can't look away.

 

[RandomEar]

[...]

Some claims from this video:

"there's a lot of those flat Earth guys out there that think because they measure the same that they've got to sound the same.
They could not be more wrong."

The irony here is that he is the flat earth guy. Measurements show the earth is round and it's trivial to prove it. Looking around you, it looks flat though at first glance. He is disregarding measurements, does some quick listening (-> "looking around") and concludes that he hears a difference (-> earth = flat).

People whose arguments are based on disregarding objective reality can claim anything they like, because even with objective evidence and logic, you cannot refute their claims -> circular reasoning.

"just because you can go in and measure the distortion levels or the noise floors and think, "Well, if it measures the same, it's going to sound the same."

Well... that's how it is. If you can analyze the signal with equipment a couple orders magnitude better than human hearing, and the signals look identical beyond the proven limits of hearing, what else would you conclude?

"They're not looking at everything else that is involved in how those things are made, because what they're doing is they're basically a voltage stepping device.
They're stepping up voltage. So it's adding gain. So there's opportunity there for a lot of things to happen and a lot of ways to change the way it sounds,
by the way it's adding that gain and the quality of everything in the path."

That's useless deflection on his part. What matters is what comes out of the little black box. If the signal leaving that box (DAC, pre-amp, amp, etc.) is perfect, then what does it matter if the capacitors inside are blue and not red? I really, really, really do not get the "logic" of these arguments many audiophiles bring forward.

...
and finally: "there is a huge variance in sound between all those different op-amps"

In this video were considered: Burson Vivid 7, Sparkos (dual discrete op-amp SS3602), etc...
[...]

Well, he's free to offer any proof of these claims. Like, any at all. I'm sure many people, including the op amp manufacturers, would have an immense interest in such results. How come they equally never provide any evidence of this for their own products?

 

[MAB]

Well, I am just trying to compare two sides’ positions. Maybe I also lost the topic: OP275 (not a discrete op-amp) vs. the top discrete op-amps mentioned in this video (hope, may be mistaken, “discrete” is not meaningful in this case).

OK, so you are here for the two-sides thing, not to learn. You lost me.

I really don't have the time or patience to read another wall of text on OpAmps. Bye.

 

[Sir Sanders Zingmore]

Well, I am just trying to compare two sides’ positions

Quite often there really aren't "two sides" to compare.
If a bunch of people say the moon is made of rocks and another group say it is made of green cheese there really aren't two sides to the debate.
Opamps are another example of this

 

[PlanarSearcher]

In Danny's castle high in the skies,

Grüße Sie,
reasonable to add, just to reflect tech stats: there is already here a test of mentioned in his video device, where that Lab replaced Op-amps: https://www.audiosciencereview.com/...douk-a5-budget-stereo-amplifier-review.61410/

Also what comes ASAP into my mind, just rough tech values:

OPA1612 (op-amp): ~0.000015% to 0.00003% THD+N (ultra-low, small-signal domain) (just took it as simplified analog to more complicated Op-amps they have mentioned)
TPA3255 (Class-D power amp): ~0.003%–0.01% THD+N (depending on power, load, frequency)

so I do not at all understand how after 0,01% THD+N they hear the diff approximately for 0.00003% before it.

 

[Ropeburn]

Grüße Sie,
reasonable to add, just to reflect tech stats: there is already here a test of mentioned in his video device, where that Lab replaced Op-amps: https://www.audiosciencereview.com/...douk-a5-budget-stereo-amplifier-review.61410/

Can you rephrase that? I fail to see the point.

However, my point is that Mister Expert fails at bloody basic electronics. Would you trust such a person's opinion and findings about more complicated things like, oh I dunno, opamps and their implementation, and the audible effects thereof?

 

[solderdude]

so I do not at all understand how after 0,01% THD+N they hear the diff approximately for 0.00003% before it.

1 word...
psychoacoustics
or...
Placebo.

People report hearing differences even if there aren't any.

Even seasoned mixing engineers have turned dials and heard changes only to find out a bit later they forgot to enable the effect.

Perception (hearing) is a funny thing people tend to trust. The same with sight, taste and smell.
I think everyone knows how easy it is to fool those senses... but hearing ? No that is trusted completely.

Take MP3 for instance.. things are literally left out yet in most cases (higher bitrates) this isn't even audible.

Moral of the story... trust your ears like you can trust your eyes, nose and smell when it comes to enjoyment. Don't trust any of them when it comes to factual differences.

Humans are flawed as analyzers.

 

[Chanur]

Eye witness testimony is notoriously unreliable, yet when it comes to audio people think they can hear the grass grow.

 

[levimax]

people think they can hear the grass grow.

Agree with your point but if you go into a quiet corn (which is a kind of giant grass) field on a hot summer day you can actually hear it growing. Many orders of magnitude louder than any op-amp change.

 

[PlanarSearcher]

Agree with your point but if you go into a quiet corn (which is a kind of giant grass) field on a hot summer day you can actually hear it growing. Many orders of magnitude louder than any op-amp change.

Based on my personal experience with light modding of the Z2 (which, in my opinion, was actually far from being an improvement caused specifically by changing the op-amp sound):


I replaced the DIP8 NE5532 (its functional role on the board is Amplifier, although I am not sure it was not already a “plug-in” replacement from the beginning) with an OPA1622 (using a DIP8 adapter), but initially not for “sound improvement.” The main reason was the nearby limitation: insufficient current for planar IEM headphones.


Later, after realizing that there was still not enough current, I replaced the current-limiting resistors near the 3.5 mm output from 100 Ω to 22 Ω — again, purely to provide enough current for planar IEMs.


As a result, formally speaking (since I did not perform any measurements, and there is also a drawback to lowering the output resistors — the common output noise may become more audible), I probably experienced some kind of “wow, it sounds better” feeling, while either accepting or ignoring the mentioned drawback.


So this is probably how many modding legends appear: modders usually do not change only the op-amps — they also change other components at the same time.

 

[LTig]

Later, after realizing that there was still not enough current, I replaced the current-limiting resistors near the 3.5 mm output from 100 Ω to 22 Ω — again, purely to provide enough current for planar IEMs.

As a result, formally speaking (since I did not perform any measurements, and there is also a drawback to lowering the output resistors — the common output noise may become more audible), I probably experienced some kind of “wow, it sounds better” feeling, while either accepting or ignoring the mentioned drawback.

This is an example which actually can change the frequency response, if the current limiting resistor is outside of the feedback loop. In this case you change the output impedance drastically. As a result the impedance curve of the load (headphone) has less influence on the frequency response. If the impedance is constant you just get more current, but if it varies (typical for most headphones) you will get a frequency response which is more flat with 22 Ohm than with 100 Ohm.

 

[diddley]

Who wants to have the last word?
Can't believe 55 pages since it is proven that it don't work.
What a waists of precious time.

 

[Thighsofsteel]

Who wants to have the last word?
Can't believe 55 pages since it is proven that it don't work.
What a waists of precious time.

Proven to people with an education, but not audiophools, who adhere to different laws of physics. You can never convince them.

 

[Sokel]

Sorry, I just missed the core of the message — did you mean that their “test clips” are not relevant?

Any movie with a disaster about to happen would be a failure without such theme.

And as the thread goes for a sad ending, timeless "Adagio for Strings" by Samuel Barber seems suitable from a decent burial*.

*(does not deserve the drama of superior works, obviously)

 

[solderdude]

This is an example which actually can change the frequency response, if the current limiting resistor is outside of the feedback loop. In this case you change the output impedance drastically. As a result the impedance curve of the load (headphone) has less influence on the frequency response. If the impedance is constant you just get more current, but if it varies (typical for most headphones) you will get a frequency response which is more flat with 22 Ohm than with 100 Ohm.

True for dynamic headphones with a varying impedance. In case of the mentioned plamar headphone it would only result in higher output signal due to voltage devision (and thus higher output current provided the opamp current limit is not reached and there is no voltage rail clipping.)

 

[PlanarSearcher]

Can't believe 55 pages since it is proven that it don't work.

;-) Maybe it is still an open chance for others to come from the opposite side and convince everyone here with new measurements — which they may have already performed but never shared with anyone.

 

[MaxwellsEq]

;-) Maybe it is still an open chance for others to come from the opposite side and convince everyone here with new measurements — which they may have already performed but never shared with anyone.

It's almost 80 years since the first operational amplifier. What realistically do you expect to turn up??

 

[PlanarSearcher]

Regarding the benefit, it depends on the application and the surrounding elements, like the feedback and the load.

I just reread your article with a focus on the OPA1612, and I noticed something. You wrote: “The low voltage noise density for the OPA1612 is notable.” That is quite confusing. In the context of “rolling,” it doesn’t really matter—but what exactly is “notable,” and under what conditions could it, if at all, cross the threshold from being merely measurable to being audible?

I also feel like I missed a scenario: “very sensitive headphones or IEMs.” Is that still only a measurable difference, or does it become relevant when the volume is turned up but no signal is present (similar to track switching)?
And the main idea may be that, in cases of ‘messed up designs’ (for example: power supply noise leaking through, oscillation or ringing, input noise being heavily amplified, overload/clipping behavior, EMI pickup sensitivity)
people can perceive a difference when choosing between something very bad and something just bad - this could explain why do they hear something as a diff while rolling Op-amps.
Could it be so?

 

[LTig]

;-) Maybe it is still an open chance for others to come from the opposite side and convince everyone here with new measurements — which they may have already performed but never shared with anyone.

Apply Occams Razor now, please, and don't waste other peoples time anymore.

 

[antcollinet]

Quite often there really aren't "two sides" to compare.
If a bunch of people say the moon is made of rocks and another group say it is made of green cheese there really aren't two sides to the debate.
Opamps are another example of this

Nor does the truth lie somewhere between the two.