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Yes – opamps swapping may make a measurable difference in a preamp

lashto

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Shorter version: No evidence. Yawn. The world is full of cranks, con artists, and dupes. I’m not impressed that you can find some without much effort.
somehow did miss this one between all those teapots flying in space .. same teapot really but it flies a lot ... sort of a flying Sisuphos (yes, that's a right spelling)

So, let me get this straight. My example of a "prototype scientist", https://cms.fnal.gov/joseph-lykken is actually part of those "cranks, con artists, and dupes". And listening to you, the real scientist will save us from those 'artists'.

In that case you won ... my lousy "10 cows" surely can't top that :)
 
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BDWoody

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In that case you won .

Whew. That's enough.

The true believers need to pony up their own efforts, not push it on those who actually understand the silliness of it.
 

Gorgonzola

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When many people claim to see a yeti, chupacabra's, aliens, UFOs, are bothered by 'chemtrails', electrosmog and all have 'similar stories' does this make it more plausible to be a real thing ?

When research would show without a shadow of a doubt the perceived differences aren't a real thing do you think people will still be hearing the same phenomenon ?
I have an engineer friend that is convinced he could hear differences between silver and copper cables.
Visited him at home and showed him without any doubt he could not hear any differences.
Till this day he still claims he can hear it.
Your copper vs. silver example verges on a strawman argument. Yes, of course, audiophile make ludacris claims sound differences -- speaker cable lifters, AC cords, silver USB cables, green markers for CD edges, 'Brilliant Pebbles', and on and on.

mikro-pebbles.jpg


I gave up on that sort of rubbish many years since. I once did some sighted listening to different interconnects; at the time, (12-13 years ago), I thought I heard differences. But I very soon realized that the differences -- such as there might have been -- were minute and, further, that I would have no chance of pick which was which in a blind ABX test.

But amplification is another matter and the topic hear is op amps. We know op amps measure different so it isn't absurd to suspect sonic differences. Amir has measured op amp difference, e.g. his review of VTV Purifi amps with SIL 994EnH and Weiss OP2-BA -- differences but too small to hear? Humm: just maybe.

(Parenthetically, I think one is much less likely to have difference between DAC filter settings than op amps, but hey, I have no proof one way or the other.)

I'll confess that I am not convinced that the standard, blind ABX testing can reveal the all differences that experienced listeners can hear in real-life music listening. Constantly citing the ABX canon doesn't definitively prove "no audibled differences" it to me.

 
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solderdude

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We know op amps measure different so it isn't absurd to suspect sonic differences.

All cables measure different too, different capacitance, inductance, characteristic impedance, ohmic resistance etc.

It is all a matter of audibility thresholds. This is very complex and there are many kinds of distortion, one more audible than the other.
To determine what is audible or not one needs to be able to properly blind test this with suitable ears (experience) and gears (low distortion over wide operating range) and lots of experience in that field as well as knowing how to test.
Just 'listening' certainly is not enough.
Below certain levels of distortion and frequency response as well as noise levels I would not expect sonic differences despite substantial differences that may be present in certain aspects.
It also highly depends on the circuit, wire routing (PCB design) decoupling, used components around the opamp, the function it has as well as rail-sticking, current limiting etc.

The crazy part is that most opamp swappers think they are as different as tubes.
There are loads of threads listing sound properties of different opamps and hardly any where one states some actually sound the same.
Plus we often do not know if oscillations have occured or some opamps were less suited in a circuit.

It is too complex an issue and the conclusion that seems to be drawn from some opamps being tested that 'might' be audible is not a conclusion that can be drawn without blind testing and with realistic signal levels under realistic loads.
As said... too complex an issue and different measurements does not mean audible differences per se.
 

SIY

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Your copper vs. silver example verges on a strawman argument. Yes, of course, audiophile make ludacris claims sound differences -- speaker cable lifters, AC cords, silver USB cables, green markers for CD edges, 'Brilliant Pebbles', and on and on.

mikro-pebbles.jpg


I gave up on that sort of rubbish many year since. I once did some sighted listening to different interconnects; at the time, (12-13 years ago), I thought I hear differences. But I very soon realized that the differences -- such as there might have been -- were minute and, further, that I would have no chance of pick which was which in a blind ABX test.

But amplification is another matter and the topic hear is op amps. We know op amps measure different so it isn't absurd to suspect sonic differences. Amir has measured op amp difference, e.g. his review of VTV Purifi amps with SIL 994EnH and Weiss OP2-BA -- differences but too small to hear? Humm: just maybe.

(Parenthetically, I think one is much less likely to have difference between DAC filter settings than op amps, but hey, I have no proof one way or the other.)

I'll confess that I am not convinced that the standard, blind ABX testing can reveal the all differences that experienced listeners can hear in real-life music listening. Constantly citing the ABX canon doesn't definitively prove "no audibled differences" it to me.

Whether you’re convinced of the need for basic controls or not is irrelevant to the actual need for basic controls.
 

BDWoody

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I'll confess that I am not convinced that the standard, blind ABX testing can reveal the all differences that experienced listeners can hear in real-life music listening.

Why? Do you have a suggestion for how someone might demonstrate their skills that doesn't require faith to believe?
 
OP
pma

pma

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All cables measure different too, different capacitance, inductance, characteristic impedance, ohmic resistance etc.
A bit unhappy comparison, IMHO. Opamp issues may be pretty real issues, under real world conditions. Heavier loading, HF nonlinearity, susceptibility to interference, just to name few. Not many here have real experience or abilities to disclose such things, unfortunately. This forum is quite good as a secondary school practical class, but not much going deeper.
 

SIY

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A bit unhappy comparison, IMHO. Opamp issues may be pretty real issues, under real world conditions. Heavier loading, HF nonlinearity, susceptibility to interference, just to name few. Not many here have real experience or abilities to disclose such things, unfortunately. This forum is quite good as a secondary school practical class, but not much going deeper.
I’ll continue staring at the ground and drooling.

Someone more cynical than I am might suspect that you’re trying to make what are straightforward and simple issues seem mysterious, arcane, and in need of your expertise.
 

BDWoody

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This forum is quite good as a secondary school practical class, but not much going deeper.

I'm sorry, the short bus was late today...

Let's see, evidence of measured differences that no one typically disputes, combined with assertions that it really could matter, but no listening test results to show how this can be a real issue for us dumbasses.

What did I miss?

 

solderdude

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A bit unhappy comparison, IMHO.

Not a comparison, just mentioning that cables also have different specs.


Opamp issues may be pretty real issues, under real world conditions.

I did not say they weren't and they certainly are not the same.

Not many here have real experience or abilities to disclose such things, unfortunately.

You need to be pretty versed in analog electronics design, have experience in PCB design as well. There aren't many of those around and even then there are designers with weird theories that refuse to show proof of their theories. Not just here though.

This forum is quite good as a secondary school practical class, but not much going deeper.
I think you might be selling quite a few people short here.
Of course, of every 1000 ASR members maybe just a few have deep enough electronics knowledge.
It is to them to try and educate. Some are more patient then others.
 

IPunchCholla

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You could have missed/avoided the point in fewer words, like SIY does :). But many thanks for the effort anyway!

Yes, I could have posted a link about what you seem to call "real homeopathy". I chose quantum-homeopathy because it sounds even more "teapoty". Hope there was something new/interesting in those abstracts and I did not waste your time. Noone was supposed to read those, because none of that matters (for the current 'argument').

The only point is that scientists do serious studies about homeopathy .. and about UFOs .. and all sorts of other 'teapots'. It does not matter if those teapots are bullshit or real, what matters is that serious studies are made about them. Not because there was any (usable) evidence but mostly because "millions of people". In itself, a lot of smoke makes it "worth" looking for a fire (and there's a 'razor' in there too.)
Such a study should be done for "musical sound".
I'd say it's not a very complicated point. Or easy to miss. But looks like l may be mistaken.


P.S.
The counterpoint made here is that it's only "worth doing" a study if you have "strong evidence". For some reason, it is also repeated quite ad-nauseam. IMO, that "counterpoint" is fairly ridiculous. 'Millions' of studies are done simply to check if there was actually any evidence.

And going (too) much further and philosophical about this, nobody owns the definition of "worth doing". A bunch of people seem to be convinced that they found it in a teapot, though.
"Worth doing" is just a choice. Thousands studies were done just because somebody had a 'hunch' .. or was bored ... or had some extra budget .. or did like butterflies or whatever. Every single one of those studies was 100% "worth doing"
So you faked evidence because you don’t even understand basic terminology?

And you still don’t understand Russel’s teapot. It’s not just about evidence, but who supplies it. The claimant (you) provides the proof.

The second point is that the research is being done and the results are freely available (in most places) with a little effort. And if the question hasn’t been answered, there is an established path for you to follow to prove your point.

Stop asking others to do the work for you. Scientists don’t owe you anything.
 

IPunchCholla

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Not a comparison, just mentioning that cables also have different specs.




I did not say they weren't and they certainly are not the same.



You need to be pretty versed in analog electronics design, have experience in PCB design as well. There aren't many of those around and even then there are designers with weird theories that refuse to show proof of their theories. Not just here though.


I think you might be selling quite a few people short here.
Of course, of every 1000 ASR members maybe just a few have deep enough electronics knowledge.
It is to them to try and educate. Some are more patient then others.
I would also add, as one of those without the necessary electrical knowledge, that there are many here, also without the electrical knowledge, but with deep expertise and/or critical abilities, that @pma is insultingly dismissive of on a fairly regularly basis, while simultaneously being completely blind to his own logical errors, that are obvious to someone with only a secondary school technical knowledge of the subject.

I appreciate your fairness and reasonability in these threads as I have learned a ton from your posts and don’t feel insulted.
 

Gorgonzola

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Whether you’re convinced of the need for basic controls or not is irrelevant to the actual need for basic controls.
Once again you miss the point. I didn't say that controls are irrelevant; I said that bind ABX testing, albeit the current canon, is possibly not an ultimately conclusive method -- i.e. I implied that a better, controlled testing method ought to be invented.
 

SIY

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Once again you miss the point. I didn't say that controls are irrelevant; I said that bind ABX testing, albeit the current canon, is possibly not an ultimately conclusive method -- i.e. I implied that a better, controlled testing method ought to be invented.
There’s lots of different formats, no idea why you’re fixated on ABX. I know I’ve linked my article on some test formats for you, but perhaps you never read it.

Nonetheless, any valid test must be double blind and level matched, basic controls. And not a single proponent of “unexplained” or unlikely differences has offered a shred of evidence supporting that over the nearly half century of these claims. So anyone with two brain cells can draw the appropriate conclusions.
 

rwortman

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Ludacris: A man named Christopher Bridges who is rapper( a person pretending to be a musician)
Ludicrous: adjective meaning foolish or ridiculous.
 

Schlippwhip68

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@Gorgonzola
Many thx for those measurements, I was looking for something like that.


Some years ago I did a similar experiment with ~the same opamps in a DAC output stage:
  • NE 5534 (original ones): they did sound very good to me and I could have lived with those "happily ever after". But after hearing the others, I thought the NEs were kind of veiled/boring.
  • LME49720: very clear/clean sound ... yes the proverbial "veil was lifted" thing, shoot me! Maybe the cleanest/clearest of them all. Cannot find any explanation for that in the measurement plots.
  • SS3602: also very clean/clear, maybe a tad less than LME but somehow with more "weight". A bit more bass energy and the whole soundstage was somehow 'heavier', like it contained more sound (or 'air' if you wish). A sort of relaxed sound, the kind you'd want with jazz/chillout music. No idea how to correlate any of that with the THD measurements. (also not 100% sure if it was the same 3602 model, AFAIR it looked same as the ones on the Spakos website.)
  • Burson V5. Did sound pretty close to the Sparkos. A tad less clean/clear, even more "weight" to the soundstage and pretty much the opposite of the 'relaxed' Sparkos sound: the kind of sound you'd want with hard-rock music. That actually seems to correlate quite well with the Sparkos & Burson THD graphs. (at least from what I know about the audible effects of THD.)
My choice/idea was to use the Sparkos for the late night music sessions and the Bursons for party-time. But since swapping was not so easy (and I am lazy) the Bursons just stayed in. I guess my Burson choice correlates quite well with my preference for tube amps (the Bursons THD spectrum looks quite tube-like).

And no, I did not do any DBT/ABX tests, the only realistic way to do that would be to have 2 devices. I did not. And I am lazy :)
No idea if I can reliably identify NE/Burson/Sparkos in a blind test, the diffs were not exactly night & day. But I am pretty sure that I can identify the LMEs: their 'clarity' also had a sort of metallic/glassy sheen which gave me a slight pressure/discomfort/pain in the ears (and a sort of light headache) after 1h or so. Yes, I tested that multiple times on different days, same strange effect. I expected to see some H5/H7/H9 in the LME plot but there is only one feeble H2 ... seems to contradict all I know about the sound of THD. But then, my test and the THD plots were done in two very different circuits.

And to finish with another beloved cliche: my ẃife/kids/neighbors/dogs/cats did not hear or confirm any of those differences and I have a strong suspicion that they couldn't have cared less.

All that is of course just subjective "stuff" and one guy's anecdote. Take it as you wish.
It's all free though, so you are not allowed to complain (too much) :p
I use a Rotel A11 Tribute for quiet chilling and my BRZHIFI 3255XLR with opa1622 for party stuff. Those 1622 are powerhouses!
 

fpitas

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Or swapping may cause ringing or even oscillation! You need to have a high frequency O-scope and know how to use it before you start swapping.
Nailed it early on. Sure, pma knows his way around a scope. But he is only claiming a measurable difference. I doubt there are any audible differences between op-amps since the advent of the 5532, unless you're loading the output really heavily.
 

audio_tony

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A couple of years ago, a friend was modifying a cheap headphone amp (IIRC it was a BT928 or something?) and I tested a few different opamps into a 270 ohm and 2.7k load. From memory, none of these sounded different. There were some surprises with the measurements though.



I also built a DAC filter for my Cambridge 851D (long story, bad Facebook purchase) and was surprised to find that an OPA134 performed better (noise was better by -6dB) than an NE5534 (likely due to source impedance I think) in the I/V stage but the NE5534 was better in the filer stage.

 

solderdude

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Opamps that are used to directly drive headphones can bring some surprises that can be audible.
I testes some (less suited) opamps 10 years ago in a typical 'C'Moy' amp with rail splitter.

 
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