Does Op-amp Rolling Work?

[levimax]

Lets focus on those cases where the amps are not 'compatible' with those speakers?
How or why? I mean if we look at the amp measurements, any differences are usually below our hearing.
So using your logic... if the differences are in audible, what makes the pairing not compatible?

There are only 3 things about amp and speaker compatibility:

1. Does the amp have enough power for the speakers in the room to play at the required level without clipping. Power before clipping is measured.

2. Does the amps output impedance interact with the speakers impedance curve to change FR. This is only a concern with high output impedance amps like some tube amps and it is measured.

3. Does the speaker present a load that is "too low impedance" for the amp to handle. This is harder and not always measured buy Amir does measure this.

If you know the measurements of your speakers and your amp you can figure out if they are compatible and even how the FR will change in the rare times this comes into play. No mysteries or magic involved.

 

[Buckeye Amps]

I'm just trying to reconcile this issue when its more than a handful of people from all walks of life that claim to hear a difference.

As has been discussed often and referenced in this thread more than a few times: psychology explains why this happens.

 

[oleg87]

Take two violins. Both are the same size, using brand new strings so that the only difference is the age. This means differences in the wood and varnish.
They should measure the same. (Or close enough). Yet you may hear the difference. (Professional musicians will. At least those who play string instruments.)

This comparison is nonsensical in a way that's central to a lot subjectivist misapprehensions of how things work. A violin has no mechanism to ensure the same output between two different violins. With op-amps, this mechanism is the *central operating principle*.

A better analogy might be taking a road trip - let's say I want to drive to another city. If I follow the same path, it doesn't matter if I'm driving a Prius or a motorcycle, if everything is working as it should I'm going to get to the same destination because there's a mechanism (the driver) ensuring that despite the vast differences in how these vehicles handle, it stays within the white lines. It won't be the exact same path, but the differences will be functionally meaningless.

 

[im_gumby]

Huh? There are plenty of amps (and DACs) that have very measurable differences that are in the audible range/able to be heard.

No one said there are not products out there that have audible differences that also correspond to measureable differences in the audible range. You seem confused.

Yes, Sorry I am. (Its my ADD at work...)
But you misunderstood. Two issues.

In terms of DACs, yes there are measurable difference. But the point was that subjectively, some prefer the sound of one over the other. I think that's the point I was trying to make ...

In looking at amps... we have a set of Amir's measurements. If we take a set of amps that are different, yet have similar measurements.
With the similar measurements we should have similar sounds and therefore should be compatible w the same speaker. Yet, some would claim that the amp is not compatible w the speaker... That's a subjective viewpoint.

Now personally, I have to wonder if I could hear any difference or incompatibility in terms of sound. Maybe over time...
IMHO its all subjective, but that doesn't make it 'snake oil' ...

 

[Multicore]

To be clear, we're not talking about the impedance issue. It was the subjective ... I thought these speakers sounded better when played using Amp A versus Amp B.

I was but I only wanted to be technically correct by excluding amps that are incompatible with the load from the conversation.

Or that the type of music you listen to will sound better or worse on these speakers, IEMs, amps, whatever.

Speakers and IEMs do indeed sound different. Often a lot.

But with the amps... so long as they are compatible and all pretty decent, the challenge is on you to demonstrate that you can repeatably hear that difference in a controlled setting. I'm not saying you didn't hear a difference. I have had this kind of experience myself too. Many here have. It's a real perception. But when all the other inputs (e.g. visual cues) and variables (e.g. level mismatch) are removed then I think you'll find it disappears or that you can't be sure any more.

 

[Buckeye Amps]

IMHO its all subjective, but that doesn't make it 'snake oil' ...

Having your own subjective feelings is not the issue. The issue starts when people try to use their subjective feeling as fact and incorrectly educate those who do not know better.

The issue becomes snake oil when manufacturers use these subjective feelings to fleece unsuspecting consumers of money on "upgrades" that have no audible impact.

 

[im_gumby]

As has been discussed often and referenced in this thread more than a few times: psychology explains why this happens.

No. That's not it. And I think that's part of the problem. If your measurements don't capture something it must be psychology.
That's a cop out ...

You're essentially saying that outside of measurements... anything that is subjective is psychology at work.

Think of it this way...

We're taste testing food.
Some will say they can't taste anything. (Thanks COVID!)
Some will say that its mild.
Some would say that its spicy.

Now we can measure something like peppers on a Scoville ?sp? scale which is objective, but even here... how hot is hot? That's subjective.

Sorry, there's more to this... and I think we're missing it.
I don't know how to bridge the gap.

Don't get me wrong... I believe in measurements to a point. But they don't tell the whole story.
I am just saying you should be so submissive of people who want to roll amps.

 

[alekksander]

finally!

 

[Buckeye Amps]

No. That's not it.

No...it really is.

 

[im_gumby]

I was but I only wanted to be technically correct by excluding amps that are incompatible with the load from the conversation.


Speakers and IEMs do indeed sound different. Often a lot.

But with the amps... so long as they are compatible and all pretty decent, the challenge is on you to demonstrate that you can repeatably hear that difference in a controlled setting. I'm not saying you didn't hear a difference. I have had this kind of experience myself too. Many here have. It's a real perception. But when all the other inputs (e.g. visual cues) and variables (e.g. level mismatch) are removed then I think you'll find it disappears or that you can't be sure any more.

Ok..
I thought you would understand that the speaker is constant, the iem is constant, the difference is the type of music.

Granted... a bookshelf that bottoms out at 45Hz and you love organ music but don't have a sub woofer... but that's not what I am saying...

 

[JustJones]

No. That's not it. And I think that's part of the problem. If your measurements don't capture something it must be psychology.
That's a cop out ...

You're essentially saying that outside of measurements... anything that is subjective is psychology at work.

Think of it this way...

We're taste testing food.
Some will say they can't taste anything. (Thanks COVID!)
Some will say that its mild.
Some would say that its spicy.

Now we can measure something like peppers on a Scoville ?sp? scale which is objective, but even here... how hot is hot? That's subjective.

Sorry, there's more to this... and I think we're missing it.
I don't know how to bridge the gap.

Don't get me wrong... I believe in measurements to a point. But they don't tell the whole story.
I am just saying you should be so submissive of people who want to roll amps.

Measurements have ruled out differences in the electronics if you want to rule out "psychology" you need to use properly controlled tests. I think that's all anyone is saying at least that's all I'm saying.

 

[oleg87]

No. That's not it. And I think that's part of the problem. If your measurements don't capture something it must be psychology.
That's a cop out ...

Uncontrolled listening impressions are not sufficient evidence that there's an "it" at all there.
I could play you the exact same audio on the exact same system, stop it and pretend to fiddle with the cables, tell you you're now listening to a fancier component, and you'll "hear" a difference. This is the mechanism for every crazy audiophile belief out there.

 

[im_gumby]

Measurements have ruled out differences in the electronics if you want to rule out "psychology" you need to use properly controlled tests. I think that's all anyone is saying at least that's all I'm saying.

Ok, so suppose you do that. Yet there is a large enough population that still claims to hear a difference.
What then?

So if we did an ABX across 3 different op amps....
Would you be satisfied?

Now that would be something I'd expect one of those YT pundits to do...

I'm more interested in if they could actually hear a change, not which one they thought was better.

 

[im_gumby]

Uncontrolled listening impressions are not sufficient evidence that there's an "it" at all there.
I could play you the exact same audio on the exact same system, stop it and pretend to fiddle with the cables, tell you you're now listening to a fancier component, and you'll "hear" a difference. This is the mechanism for every crazy audiophile belief out there.

That is solved w ABX testing.

The only problem... someone would find fault w any test you conceive.

 

[antcollinet]

Sure. To a point.

Take two violins. Both are the same size, using brand new strings so that the only difference is the age. This means differences in the wood and varnish.
They should measure the same. (Or close enough). Yet you may hear the difference. (Professional musicians will. At least those who play string instruments.)

1 - If there is a difference to be heard, it can also be measured.

2 - Amps are not musical instruments. They are pieces of equipment intended to amplify sound without otherwise making changes.

 

[antcollinet]

Some people can hear the difference,

So they should demonstrate it, with a properly controlled blind test.

Or stop going on about it.

Because the engineering, measurements and psychoacoustics says there is nothing audible to hear - assuming the op amp is working correctly.

 

[DMB90]

They can disagree but it is true.

The bypassing allows for a more broad integration with existing input board setups manufacturers already had in place, so as to not force manufacturers to redesign something from the ground up. I can guarantee Hypex did not put bypass into their module because they felt their design could be audibly improved by a Sparkos or Weiss or Sonic Imagery.

2.5.2 Buffered / Unbuffered Input
The NCx500 OEM incorporates a buffer stage to increase voltage gain and input impedance and therefor make
it easier to drive the amplifier. This buffer stage can be omitted so control over the design of this stage and
thereby tuning to a ‘house sound’ can be done more easily. The selection of either using the module buffered
or unbuffered can be done through jumper settings on J7/J15.

 

[antcollinet]

Ok, so suppose you do that. Yet there is a large enough population that still claims to hear a difference.
What then?

What then - is all those perceptions of difference are based on sighted uncontrolled listening. Everyone is subject to perceptive bias. It happens to us all the time. It is how our senses work.

So if we did an ABX across 3 different op amps....
Would you be satisfied?

Bearing in mind ABx is comparing only two devices at a time. So OpAmp1 against OpAmp2, then 1 against 3, then 2 against 3.

If those tests were sufficiently well controlled, and if the listeners were able to correctly identify a difference at least 9 times out of 10 for each comparison, we could then go back to the measurements to identify what has changed sufficiently to be audible - and why.

 

[Buckeye Amps]

2.5.2 Buffered / Unbuffered Input
The NCx500 OEM incorporates a buffer stage to increase voltage gain and input impedance and therefor make
it easier to drive the amplifier. This buffer stage can be omitted so control over the design of this stage and
thereby tuning to a ‘house sound’ can be done more easily. The selection of either using the module buffered
or unbuffered can be done through jumper settings on J7/J15.

Nothing you quoted contradicts what I said....

House sound is not the same as audibly improved performance.

 

[antcollinet]

‘house sound’

What do you think house sound consists of?

Audible distortion, or non flat frequency response? Because whatever it is it is measurable, and I've yet to see measurements of any hypex or purify based amp that has either of those two things. (I'm ruling out noise because no-one would add that for a house sound)

Sure - a manufacturer can create a house sound in their own buffer. But then they have degraded the sound quality in some way.