I think a little time to do some research would be good. A few days off from this thread might make you less likely to try to explain what you've already made clear and do some more reading.
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Does Op-amp Rolling Work?
- Thread starter amirm
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I think a little time to do some research would be good. A few days off from this thread might make you less likely to try to explain what you've already made clear and do some more reading.
oleg87
Addicted to Fun and Learning
Well, no one's saying op-amps are interchangeable, there's a reason companies make a gazillion different models, and they should be selected to work well for the particular application. Since Bruno knows of what he speaks on this topic, I have to assume he made that comment for a reason that's grounded in engineering reality as opposed to the usual process of sticking random parts in dip sockets (or hanging them off tangles of wire) and hoping for the best.
(Though whether that engineering reality means audibly meaningful performance differences might be a different question, though of course there's no harm in having plenty of performance margin)
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tmtomh
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You could make the exact same argument about whether the earth is round or flat. There's clear and conclusive evidence that the earth is round - but subjectively many people don't see the curvature of the earth when they look at the horizon (although if they actually thought about what a horizon is, they'd realize they are in fact seeing the earth's curvature), and they don't experience things in the distance of their vision as being curved. In that case we would be silly to try to claim that the reality is "somewhere in the middle" or that insisting the earth is round is "dogma" of which we should remain skeptical because people subjectively experience it as flat so there must be some measurement of the earth that will account for that flatness.
The only difference is that you happen to believe the earth is round and you don't happen to believe that op amps all sound the same (unless it's a really bad op amp with the poor measurements to prove it).
But the argumentative tack you're taking here, and your insistence that the truth must be midway between what different people say, without regard for how supported or unsupported by evidence each "side" or "extreme" is, is precisely the same as saying the Earth might not be round.
Old_School_Brad
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For 20.000 Hz and different voltages this is the min. required slew rates:
- 2 V = 0.25 V/uS
- 4 V = 0.50 V/uS
- 10 V = 1.26 V/uS
solderdude
Grand Contributor
No they are all human.
The psychological factor of 'knowing' what is being listened to.
It's what the audio industry relies on.
daniboun
Major Contributor
Exactly. Right word should be bypassed )
This is attractive if your DAC / preamp puts out good voltage
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antcollinet
Grand Contributor
Again - no. Engineers design this stuff. They also know how to test it.
antcollinet
Grand Contributor
Nothing - or at least those of us you are "debating" with are not missing anything.
You, on the other hand are missing all the information on psychoacoustics, and perceptive biases.
Try this as a first clear example.. It is not the same bias as those that apply when listening to audio gear, but it is an easy example of how the brain changes what we hear, based on what we see. And even when we know how we are being fooled, we are unable to stop it.
All the optical and audio illusions you've ever seen come from these sorts of biases also.
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DanielT
Master Contributor
Of course they are.
Or you could say they are part of a religious cult. Some actually come here to ASR and manage to get deprogrammed.
Much better sound via op amp swap is a:
Edit:
It is up to those who claim something to prove it. Show me a single seriously performed blind test where it has been shown with statistical certainty that there is an audible difference when swapping op amps. Then done according to all the rules of blind testing with any good modern op amp plus with the NE5532 as a starting point. With a good modern working DAC, with op amps that fit in it, that do not oscillate if they are popped into the DAC.
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antcollinet
Grand Contributor
Then when you've looked at "McGurk" and seen how easy it is to hear differences when non exist, try out your own ability to hear actual differences - and how bad distortion has to get before you personally can hear it.
Listening Test
morillon
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Haskil
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Take two new violins made by the same luthier using exactly the same model: they will not be identical, just as two pianos following one another in the production line at Steinway, Yamaha, or another piano maker will not be identical.
And a high-level violinist, like a high-level pianist, will notice this when playing them. In the same way that the same piano played successively by all the candidates in an international piano competition will sound different in the same works depending on the candidate...
The problem here, which definitively distances us from an electronic circuit designed to reproduce a signal without distorting it, is that the violin and the piano are used to produce a sound, not to reproduce it... And that this sound will be different, in any case, on the same instrument, depending on the musician playing it...
A short film is circulating on Facebook where we see Anne Sophie Mutter in the street in Paris picking up a violin from a small instrument dealer's stall: a very, very modest instrument... she tunes it, plays it, and the sound that comes out is marvelous... it's her own... give this modest violin to a violinist who doesn't have this violinist's fabulous sound, and the unfortunate violin will sound very different...
To a woman who told Jasha Heifetz that her violin had a fabulous sound, the violinist responded by grabbing his violin and carrying it to the lady's ear: "Do you hear something? The sound coming out is mine."
You keep on asserting the same, despite the (wasted) time Amir took to explain to you, and so you have obviously no clue about measurements, how to perform them, what they mean and what is your own personal hearing threshold for each.
So no need for an analogy, if it’s unclear to you, read available documentation on the topic. If you’re curious to know more, just ask, but stop asserting measurements can’t show the complete story. There are places where measurements are complex and reach the limit of current technology and knowledge, but clearly not in audio.
Haskil
Addicted to Fun and Learning
The problem with this AI response that is as close as two peas in a pod to the same nonsense some people are saying is that it is impossible to measure the frequency response of a violin until it is played by someone! A violinist using a bow that scrapes the strings while the violinist's left hand presses the strings to determine the pitch frequency of the note played and the variation around that frequency called vibrato... The violin, the bow, the tension of the bow hair that the violinist adjusts, the violinist's arm, his fingers, and his... ears then become a changing instrument...
Because the same violinist playing the same violin, two days apart, in rooms with different acoustics, will produce a different sound spectrum from the same piece played... His sound will remain the same and will be recognizable if he has a strong personality, but the sonic balance will be different... This is why analogies between electronic circuits and musical instruments are always doomed to failure...
Electronic circuits and speakers are precisely what are asked to be transparent to all these variables...
Nice comparison. Thanks for doing this. The result is as expected. In any case, these power amplifiers are not necessarily pushing the op-amps to their limits. There might be larger differences in other types of circuits. One that comes to mind is a PHNO pre-amp. As this has higher gain, the noise performance of the IC will influence the overall noise of the pre-amp. NE5532 is a great IC but being a little old, there are now parts that perform considerably better noise wise. The LM4562 (LME49720) is one example and the OPA1612 is one of the best in this regard. In real life applications, there will be very small differences between these but considering that the LM4562 is rather cheap and widely available, this is the one I'm using in most of my projects. Performance is outstanding. I have a few OPA1612 that I want to test in a pre-amp and a PHONO pre-amp. I'm curious weather I can measure any differences between these two with my setup (Cosmos ADC + Scaler).
morillon
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Fosi Audio Box X5 Phono Preamp Review
This is a review and detailed measurements of the Fosi Audio Box X5 stereo Phono stage. It was sent to me by the company and costs US $109.99. Company manages to bring a touch of class in a category that is universally utilitarian with those rounded corners and orange power button. Flexibility...
www.audiosciencereview.com
and the efforts from pma:
Measuring noise and SINAD of MM phono preamps properly
Measuring noise and SINAD of MM phono preamps properly 1. Intro It is a temptation to measure phono preamplifiers the same way as if it was a common link stage preamp, to drive it from very low generator impedance and to measure the preamp output voltage. Similar way as when measuring with AP...
www.audiosciencereview.com
;-)
There are many applications where opamps are used. Audio is just one and it's not a really demanding one. A cheap opamp will work just fine as THD and noise are really good for cheap IC's. If you go higher in frequency and go into RF, there are dedicated opamps for these. You might need a rail to rail input or output in your application and there are opamps that can do that. You will find opamps in almost any decive that has an analog front-end. Oscilloscopes use them, audio analizers, RF boards and many more. The opamp is one of the best discoveries in my opinion
antcollinet
Grand Contributor
Phono Pre is obviously an application where noise performance of an Op Amp can make an audible difference.
That is not typically where people are rolling op amps though. It is in line level circuits in DACs and AMPs.
Further - randomly swapping op amps in a phono preamp without understanding the design, and performing all the design calculations - is even more likely to result in detrimental performance than in Dacs and Amps.
Finally, if the designer of the phono pre has not ALREADY included an appropriately low noise device into the pre-amp, we should not be gifting him our custom in the first place. This is where Amir's measurements of stock devices come into play.
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