Does Op-amp Rolling Work? [Video]

[Ropeburn]

Let's give Danny the benefit of the doubt and say he didn't deliberately put his finger on the scale and make his recommendations progressively louder, then something is unusual with those 'artisanal' op-amps as they are louder in the recordings... Maybe someone would know how that could be possible without a deliberate cheat? The most recommended one is actually 2dB louder and clipping the recording. This is now 2 of these op-amp comparisons by true believers that are tainted in the same manner in favor of the desired conclusion. A 2dB boost over the entire audible band should be so easy to distinguish, even an audiophile's wife could hear it.

There are three basic ways of using an opamp as a buffer: inverting and non-inverting for single-ended

and differential for balanced inputs

In all three cases, the gain is entirely determined by the circuit (the ratio of the resistors), and NOT by the opamp itself. The input impedance of any opamp is so high (megaohms), in any competently designed circuit a change in opamps (with remotely compatible types) can not have a significant change in gain.

Which means if the device isn't doing weird stuff by design, a gain change of 1 or 2 dB is impossible. Therefore it must be either sloppiness or deliberate manipulation in this case. Take your pick.

 

[restorer-john]

A 2dB boost over the entire audible band should be so easy to distinguish, even an audiophile's wife could hear it.

From the other room, no less.

 

[Ropeburn]

From the other room, no less.

You mean, from the kitchen. Isn't that the usual thing? The wife somehow is always in the kitchen when clearly hearing the usual snake oil improvements. It's almost as if these delusional people were also sexists. Who woulda thunk it.

 

[amirm]

Let's give Danny the benefit of the doubt and say he didn't deliberately put his finger on the scale and make his recommendations progressively louder, then something is unusual with those 'artisanal' op-amps as they are louder in the recordings... Maybe someone would know how that could be possible without a deliberate cheat?

Yes. When you go to change the op-amp, it is so easy to touch the volume control. Unless you measure the output, which of course they did not, you can't level match. This is what I did after changed the op-amps. Not for that reason but to make sure I was testing at the same 5 watt output as my review. It is likely that neither one of them thought that levels had to be the same. And worse yet, couldn't tell after they played the files!

Now that is giving them the benefit of the doubt. It is kind of hard to do that when files progressively got louder toward their favorite option. And even EQ changed. These point to experimenting until they found the results they wanted, not knowing that in this day and age, people do quick analysis.

We know they lied about this work as Danny claims they were experimenting with this idea for "months." Yet, they repeated my exact test of Douk A5 with these op-amps. Clearly he is lying about this. If so, then he is liable to lie about other things as well.

 

[DanTheMan]

We know they lied about this work as Danny claims they were experimenting with this idea for "months." Yet, they repeated my exact test of Douk A5 with these op-amps. Clearly he is lying about this. If so, then he is liable to lie about other things as well.

I forgot about that one even though it's the most obvious one he said. Even the most DAC power cable connector hearing Dannyphile knows the truth on that one, but I bet they equally appreciated the trolling effort and forgave it instantly without a pause. I sure didn't read any of them calling him out on it. At least one of us did--who knows if that comment is still up.

 

[DanTheMan]

Maybe the ultimate counter-trolling would be to put 2 level matched sound samples up with the 2 different op amps untouched by EQ with random file names. Of course you'll be accused of having the same file up both times....

Devising an online ABX comparator for common audiophile myths: DAC power cables, expensive crossover parts, cable lifters, etc... Then also have stuff where known audible difference can be compared as well. If I had any idea how to build such a thing, I'd have already done it and I doubt it would solve any debates.

 

[restorer-john]

You mean, from the kitchen. Isn't that the usual thing?

Absolutely, but I was attempting to not stir up the PC crowd with the "wife in the kitchen" comment...

 

[Ropeburn]

Absolutely, but I was attempting to not stir up the PC crowd with the "wife in the kitchen" comment...

A good scientist, even an amateur one, is obliged to call out any bullshit as he stumbles upon it. The truth does not care about politeness.

 

[shuppatsu]

We have dueling videos on op-amp rolling the Douk A5 from Amir and his bestie, Danny from GR-Research.

Shockingly, they come to diametrically different conclusions. Who to trust? Maybe the one who doesn't have comments like these in the replies:

I loaded all three sound samples into Audacity and selected exactly the same section from all of them and did a spectrum analysis. The result is that the samples were not recorded at the same volume. The differences are about 2 dB and it also seems that the high-pass filter was not in the same position each time. Changing the operational amplifier cannot cause those changes in the spectrum at low frequencies, because the operation of the operational amplifier starts from DC. Investigate for yourself. That much of a difference in sound pressure is noticeable and the one that is louder sounds better. These sound samples do not prove anything about the significant superiority of the new operational amplifiers. An absolute prerequisite for comparing the samples is that the settings are the same and the signal level is ensured to be consistent.

 

[Old_School_Brad]

Absolutely, but I was attempting to not stir up the PC crowd with the "wife in the kitchen" comment...

It's interesting. Technically, you could say "my bitch in the kitchen" when referring to a gentle female Labrador resting in her bed, and it wouldn’t be offensive in any way.
Since dogs have significantly better hearing than humans, the statement is also likely accurate, though it naturally depends on how far your kitchen is from the sound system. -Or if she cares at all.

If someone takes offense, it likely reveals more about their own preconceived notions than the statement itself.

 

[Old_School_Brad]

We have dueling videos on op-amp rolling the Douk A5 from Amir and his bestie, Danny from GR-Research.

Shockingly, they come to diametrically different conclusions. Who to trust? Maybe the one who doesn't have comments like these in the replies:

Or this one;

Has anyone verified the accuracy of these comments on loudness?

 

[solderdude]

There are three basic ways of using an opamp as a buffer: inverting and non-inverting for single-ended

View attachment 437857

and differential for balanced inputsView attachment 437858

In all three cases, the gain is entirely determined by the circuit (the ratio of the resistors), and NOT by the opamp itself. The input impedance of any opamp is so high (megaohms), in any competently designed circuit a change in opamps (with remotely compatible types) can not have a significant change in gain.

Which means if the device isn't doing weird stuff by design, a gain change of 1 or 2 dB is impossible. Therefore it must be either sloppiness or deliberate manipulation in this case. Take your pick.

The non inverting circuit shown above is not a 1x buffer circuit but used when a gain >1 is required.

Below the most common buffer circuits (the one on the right is what is mostly used as a buffer (1x gain = 0dB)

 

[totti1965]

I'm from Germany, which means: original Milli Vanilli country... and the 80s were "my" time!
That's why for me this YouTube comment from @amirm was definitely the funniest! LMAO!

@anarchohelenism​

vor 4 Tagen
IDK Amir... I rolled my Opamps and it really opened up the soundstage, tightened the bass, and it made it sound like Milli Vanilli was in the room with me



@AudioScienceReview
vor 4 Tagen
My condolences.


thw

 

[antcollinet]

Maybe someone would know how that could be possible without a deliberate cheat?

I can't think of any way.

In an op amp circuit, the gain of the circuit is defined by the ratios of the resistors in the circuit - not by any characteristics of the op amp. There is no way for a change in op amp to cause a significant change in levels.

It is possible (I guess) for the recording level to be insufficiently well controlled - but given that it should not be necessary even to touch this between recordings it would be (as a minimum) gross incompetence in the test method to get it wrong.

 

[antcollinet]

Absolutely, but I was attempting to not stir up the PC crowd with the "wife in the kitchen" comment...

It is definitely not a sexist trope.

Studies have shown that the nature of cooking causes a discombobulation in the wibbly-wobbly timey-wimey of the space-time continuum in the vicinity of the cooking.

The specific nature of the discombobulation is to magnify inaudible differences in sound to the extent that anyone in that vicinity can easily hear them— no matter the tin-ness of their ears.

The bias towards it being a wife in the kitchen is only due to the gender bias towards husband-ness of their audiophile-playing-with-inaudble-differences-in-sound partners.

trufax. 

 

[restorer-john]

It's interesting. Technically, you could say "my bitch in the kitchen" when referring to a gentle female Labrador resting in her bed, and it wouldn’t be offensive in any way.
Since dogs have significantly better hearing than humans, the statement is also likely accurate, though it naturally depends on how far your kitchen is from the sound system. -Or if she cares at all.

If someone takes offense, it likely reveals more about their own preconceived notions than the statement itself.

Would the audiophile wife who was comparing opamps in the listening room whilst her husband cooked dinner in the kitchen take offense? Would the hen-pecked husband take offense being labelled as the wife in the kitchen in that instance? Were either of them even in the kitchen? Maybe the wife/husband was cleaning the bathroom and still heard the difference.

The "other room" covers all those bases. She (or the husband) could have been dressed in thigh-high boots, lingerie, with a whip in hand in the dungeon and clearly perceived an audible difference when those opamps were plugged in and out...

 

[JSmith]

discombobulation in the wibbly-wobbly timey-wimey of the space-time continuum

Love the Doctor Who tie in there... maybe a hint of Douglas Adams too.


JSmith

 

[antcollinet]

Love the Doctor Who tie in there... maybe a hint of Douglas Adams too.


JSmith

No - only Dr Who.

I'm a massive fan of DA, but his work was not in my mind - at least not consciously.

 

[Old_School_Brad]

Would the audiophile wife who was comparing opamps in the listening room whilst her husband cooked dinner in the kitchen take offense? Would the hen-pecked husband take offense being labelled as the wife in the kitchen in that instance? Were either of them even in the kitchen? Maybe the wife/husband was cleaning the bathroom and still heard the difference.

The "other room" covers all those bases. She (or the husband) could have been dressed in thigh-high boots, lingerie, with a whip in hand in the dungeon and clearly perceived an audible difference when those opamps were plugged in and out...

I won’t comment on what’s plugged in or not, but in the dungeon, one should also be mindful of not having their hearing too affected by the supersonic cracks of the whip. Both the dungeon and its visitors deserve proper treatment to avoid this.

In any case, this would be the perfect speaker for a dungeon:

The Gimp Speaker

 

[Matt_Holland]

In any case, this would be the perfect speaker for a dungeon:

The Gimp Speaker

lol!!!

Love inanimate objects with faces