Op Amp Replaced: Fosi V3 Monoblocks LM4562NA/NOPB $8x3

[jmdesignz2]

The TPA3255 is magnitudes worse than both the NE5532, Sparkos and LM4562 so no.... it really cannot get better than the TPA3255 which basically is THE bottleneck in performance.


The rationale was the recommendation by Fosi.

Besides ... even if the 2nd op-amp that was not replaced was just one half of the balanced signal and performance somehow increased through the presence of another op-amp there should STILL be a measurable improvement. There isn't any.
The 3rd op-amp (unbal->bal) you replaced isn't even in use when using balanced input.

Have you seen the testing done by @MAB and @pma ?
These measurements do not have the 'handicap' of the TPA3255 which determines the measured and sonic performance.


it only seems that way.
The TPA3255 is the limiting factor in ALL measured aspects.


Then YOU either DO a PROPER test yourself (blind, level matched, witnessed, statistic relevant and checked for operation) or you make use of proper tests that have been done.
Your subjective findings are not admissible as 'proof' I'm afraid.

Of course... alternatively ... you can trust your hearing and those of other 'op-amp swappers' (there are soooo many of them) and stop trying to convince ASR members that your hearing is trustworthy and we must believe you.
There is no objective evidence on your side nor is there any rationale on your side. Only your subjective observation.

You do realize that the frequency response (as well as distortion) in the higher frequencies are limited by the TPA3255 and the NE5532 and LM4562 both are magnitudes 'better' than that of the TPA3255 (and its output filter) which both have nothing to do with PSSR of op-amps either.

Hi- never claimed my subjective experience was "proof" and I clearly stated what I experienced was subjective

 

[voodooless]

Isn’t imagination great?

 

[jmdesignz2]

You can and should do this test yourself. It's the best way. Do what solderdude said before.


I like this proposal. I want to hear the differences that @jmdesignz2 can hear. And then we can analyze the files to find the corresponding signal differences.

If the amps are sent somewhere else for test it won't be the same and there will be room for doubts.

I like this too- if someone wants to send me the appropriate gear?

 

[Salt]

Especially given that the AliExpress page says this:

View attachment 476376

I'm positively surprised the AE sellers provide such informations that gives, at least, some flavour of Responsibility

 

[solderdude]

Hi- never claimed my subjective experience was "proof" and I clearly stated what I experienced was subjective

Correct you never claimed that but you present perceived things and theories as follows:

Most obviously there’s more tonal textures for certain things such as fingertips on strings, instrument surfaces. Example is hearing a truer representation of a slightly moist finger sticking to a wood surface. Palm vs finger strikes, drum skin textures

They are described as facts...

I’m extremely familiar with the tracks having listened to some for more than 10 plus years I’m using to subjectively evaluate them and I’m hearing some obvious differences especially in the higher frequency instruments sounding more true, texture and nuance

They appear facts to you and appear indisputable and cannot possibly come from anything else then the op-amp swap with the higher specced ones.

I am certainly discerning differences that are positive

so definitive but no 'proof' of actual existence ?

I am certain these have improved the quality of sound. Most likely due to the enhanced PSRR.

Certain... but you don't see any proof that the LM4562 actually makes a difference ?
But you are certain that the LM4562 is responsible.
... because you are experienced and well known with the system/recordings .. ?

but that a change in a critical electrical component is a change to the signal chain

The logic escapes me... because A; the op-amp is not a critical component here. It just provides a little gain as the TPA is limited in gain. The critical component here is the output stage (TPA).
B: Performance of an op-amp is mostly determined by the components around the op-amp (which obviously do not change).
C: It has been show (in measurements) how minute the actual changes are, certainly compared to those of the bottle neck (TPA + filter).

While the resulting sonic differences are subtle and don't make the sound a 'new instrument,' they change its character, texture, and resonance,

Where is the proof that this actually happens ? You state this as a fact.
To change the character/texture you would need to change the level of the harmonics and or fundamental which requires harmonic distortion reaching audible levels and/or changes in frequency response which we know does not happen.
One can only change resonances by either damping them (at the source or with very smart DSP) or prolonging them (reverb/compression) but this would then happen to all instruments/voices and not to just a or 2 instruments and in ways that 'suit' that instrument. In other words... you are 'experiencing' something that makes you believe that is happening and even suspect PSSR might be the reason. PSSR is totally irrelevant and can not cause these effects.

The fact that these changes are not as easily charted by a simple measurement doesn't make them inaudible to a trained listener

Is that a fact ? is there actual scientific proof for that fact ? Or... is it a theory and not a fact.

 

[jmdesignz2]

Correct you never claimed that but you present perceived things and theories as follows:

They are described as facts...


They appear facts to you and appear indisputable.


so definitive but no 'proof' of actual existence ?


Certain... but you don't see any proof that the LM4562 actually makes a difference ?
But you are certain that the LM4562 is responsible.
... because you are experienced and well known with the system/recordings .. ?


The logic escapes me... because A; the op-amp is not a critical component here. It just provides a little gain as the TPA is limited in gain. The critical component here is the output stage (TPA).
B: Performance of an op-amp is mostly determined by the components around the op-amp (which obviously do not change).
C: It has been show (in measurements) how minute the actual changes are, certainly compared to those of the bottle neck (TPA + filter).


Where is the proof that this actually happens ? You state this as a fact.
To change the character/texture you would need to change the level of the harmonics and or fundamental which requires harmonic distortion reaching audible levels and/or changes in frequency response which we know does not happen.
One can only change resonances by either damping them (at the source or with very smart DSP) or prolonging them (reverb/compression) but this would then happen to all instruments/voices and not to just a or 2 instruments and in ways that 'suit' that instrument. In other words... you are 'experiencing' something that makes you believe that is happening and even suspect PSSR might be the reason. PSSR is totally irrelevant and can not cause these effects.

Is that a fact ? is there actual scientific proof for that fact ? Or... is it a theory and not a fact.

I’m not saying the op amps have distorted or added anything. Is that what you’re saying?

You don’t believe a reduction in noise and distortions at the beginning of the signal chain benefit a truer end result output?

 

[solderdude]

I’m not saying the op amps have distorted or added anything. Is that what you’re saying?

No, that's not what I am saying. I was saying what would be required to happen for recorded sounds to change in the ways that you describe the perceived (that word is the crux) differences.

You don’t believe a reduction in noise and distortions at the beginning of the signal chain benefit a truer end result output?

I don't have to believe. It is logic and engineering (laws of nature / science). There are even online calculators that can show you what -120 and -100dB will contribute to -80dB signals.
On top of that ... the human dynamic range (when listening to music) is around 70dB so how can some change far below that affect 'subtleties' unless they are much smaller and thus VERY measurable... and no difference is measured.

Noise and distortion are determined by the bottle neck (the TPA).
Now ... if the original op-amps used are worse than the bottle neck or in the same ballpark and you change them for something that is much better than you are right.

But if distortion, FR, noise of the original op-amp is factors lower than the bottleneck it simply does NOT play a role.
When you replace it for an even lower noise, higher BW, lower distortion op-amp NOTHING changes at the end of the bottle neck.

The NE5532 is magnitudes better than TPA performance. The NE5532 thus does NOT contribute to noise/distortion/FR. Now you change that part for another part that also does NOT contribute to noise/distortion/FR how can that be audible if there is no contribution by the op-amps ... simply because both op-amps are way better than the worse part in the chain.

 

[Multicore]

I like this too- if someone wants to send me the appropriate gear?

Do you have an audio interface? About $100 if not. Then we need a cable from which you cut off one end and bare the balanced signal pair (ignore the ground) and connect them to the speaker or amp terminals in parallel. Is ~+16dBu for full scale input on the audio interface enough? I'm not sure. If not we need to rig up a potential divider, i.e. two resistors. Then it's just a matter of recording with Audacity or whatever. DIY is fun!

 

[Sir Sanders Zingmore]

Of course not lol, I said so at the beginning of this post. That’s why I’m welcoming a test.

So if Amir measures the op amps “correctly” and finds they make no difference (hint, that’s exactly what he’ll find…) will that change your view?

 

[jmdesignz2]

So if Amir measures the op amps “correctly” and finds they make no difference (hint, that’s exactly what he’ll find…) will that change your view?

sure, why not LOL

 

[caught gesture]

It's easier to fool people than to convince them that they have been fooled.

 

[solderdude]

Do you have an audio interface? About $100 if not. Then we need a cable from which you cut off one end and bare the balanced signal pair (ignore the ground) and connect them to the speaker or amp terminals in parallel. Is ~+16dBu for full scale input on the audio interface enough? I'm not sure. If not we need to rig up a potential divider, i.e. two resistors. Then it's just a matter of recording with Audacity or whatever. DIY is fun!

All 'op-amps have a sound' believers discriminating and experienced listeners should reply something like:

I can hear undeniably a subtle but obvious differences in sound quality between general purpose NE5532 and the far superior for audio designed LM4562.

LM4562 vs NE5532: What are Differences and How to Choose - Avaq

The comparison between the LM4562 and NE5532 operational amplifiers (op-amps) is an essential journey into the world of audio electronics, where the intricacies of sound quality and performance are paramount. In this article, we will delve into the distinctions between the LM4562 and NE5532 op-amps.

www.avaq.com

Comparing LM4562 and NE5532 Selecting the Best Op-Amp for Your Project

The LM4562 and NE5532 are two popular operational amplifiers used in audio electronics, each with unique benefits. The LM4562 offers clear, detailed sound with low distortion, ideal for audio systems. The NE5532 is budget-friendly, reliable, and great for home recordings or cost-conscious...

www.ic-components.com

LM4562 vs TL072 and NE5532 ..impossible ?

I got curious today and decided to try and see how our old friends compared against the latest and greatest (?) chip. The chips were put into the active filter at the output of a DAC ( Zhaolu V2.5 ). Results . 1. LM4562 -- not by a very large margin ! 2. TL072 was VERY good !! Equal or better...

www.diyaudio.com

DAC LPF Op-amps Comparison OPA1642 NE5532 LM4562

diy audio system

orronoco.blogspot.com

From The NE5532 to The LM4562: Which OP AMP is Right For Your Application?| Blogs | CHIP-CHIP LIMITED

Also for audio amplifiers in analog circuits, choosing the NE5532 or the LM4562, analyzing both operational amplifiers from a variety of perspectives, and providing advice on the best choice

chip-chip.com

The best sounding op amps for audio work.

G'day all, I guess that this sounds suspiciously like the subject of 'op amp rolling, but actually it isn't. As much as I think that op amps do have a 'sound', in recent days I've been revisiting the LM4562 and sonically wise, to my ears it doesn't really have that 'typical' op amp signature, it ...

www.stereonet.com

These people can't all be delusional and they all hear the obvious differences so its real. Test equipment only makes basic measurements.

When using an ADC that does not have the LM4562 in its audio path then you can't record the subtle but obvious differences as the cheap NE5532 simply can't convey those subtleties.
When one listens to such a recording that doesn't have the, far superior measuring, LM4562 in it you won't be able to hear those subtle but obvious differences.
This means that even if I record it with a high-end recording device that uses LM4562 or better in it you will not be able to hear the differences between the files made with the different op-amps.

All you need to do to hear the differences for yourself is to have a DAC or amplifier where you can swap all op-amps (that is crucial) and listen to music with the cheap NE5532 in it and then change it to LM4562 and you will hear the difference immediately. The superior performance of the Texas Instruments LM4562 that is designed for audio purposes ( and comes with a reliable spec sheet) simply lifts a veil the cheap general purpose NE5532 simply cannot do.

As Armin did not measure the Fosi with all 3 op-amps changed for the, far superior Texas Instruments specifically for audio designed LM4562, but changed only one unreliable specified non Texas Instruments designed op-amp you won't see the improvements on the basic measurements as there still are 2 NE5532 in there which obviously are not able to convey the musical subtleties the LM4562 brings.

It is subtle but night and day... especially when you listen to a device with the cheap NE5532 during the day and the LM4562 during the night.

So Amin should redo the test with all op-amps changed for LM4562 and then the basic measurements will likely show differences.... and if they don't... realize that you can't capture the subtle things we can clearly hear with our ears, compared to basic measurements.
The differences are real and obvious.

 

[MAB]

Apologies, I was not more clear-

My examples weren't intended to be analogies of scale
The argument is not that an OpAmp changes the sound as dramatically as a violin changes from a cello, but that a change in a critical electrical component is a change to the signal chain

A better example would be hearing more of a difference in the nuances of the seeds in a maraca or more difference in emphasis/attack, hearing a more nuanced finger vs palm movement on a drum skin. Hearing more nuance in the texture of a drum skin etc.

While the resulting sonic differences are subtle and don't make the sound a 'new instrument,' they change its character, texture, and resonance, which are all perceived by the human ear. The fact that these changes are not as easily charted by a simple measurement doesn't make them inaudible to a trained listener

How about the Glockenspiel? Sorry dude, I was trying to get you to stop patronizing me with all of these descriptions of sounds, spoken in softly poetic phrases. I get it, you are doing the argument by authority thing, you are trained, you hear all of these sounds you can rattle off by name, and I must be some silly boy who has never heard the world with your ears. At least I have that going for me!

Look, I have already demonstrated to you that the LM4562, vs. just about any other reasonable OpAmp is almost 2 orders of magnitude lower distortion than the TPA amp module, which is already at the outer edge of human hearing under the best circumstances. Other people trying to speak to you very reasonably, and explain. You won't learn or listen, but wait you offer to test your ideas if only we can:

I like this too- if someone wants to send me the appropriate gear?

Really, all we have to do is mail you some testing gear and you'll get right on it?!? I LMFAO at the absurdity.

 

[SnakeLord]

All 'op-amps have a sound' believers discriminating and experienced listeners should reply something like:

So Amin should redo the test with all op-amps changed for LM4562 and then the basic measurements will likely show differences.... and if they don't... realize that you can't capture the subtle things we can clearly hear with our ears, compared to basic measurements.
The differences are real and obvious.

My LM4562 sounds best when its full moon.

I have also noticed last time when we had a blood moon, i swapped my Bursons 7 Classics into the buffer and boy oh boy did it sound spacious and precise! I was listening to my special Hans Zimmer Orchestra Vinyl recording played over my CD-ROM PC.
You could feel and see all the diffrent type of fingers playing the instruments, you could actually tell their skin colour, some of them were white, some of them were yellow, some were black, some were bald, some were humping, some slept the night before bad, some havnt eaten for 3 days, some needed to go to bathroom, some were already going, some had their nails done.

It was night and day! Space in Time! Finger in Rectum!

Just try it!

 

[RexrothPigeon]

Is the audio market swimming on snake oil? )

You sweet summer child

 

[Multicore]

Do you have an audio interface? About $100 if not. Then we need a cable from which you cut off one end and bare the balanced signal pair (ignore the ground) and connect them to the speaker or amp terminals in parallel. Is ~+16dBu for full scale input on the audio interface enough? I'm not sure. If not we need to rig up a potential divider, i.e. two resistors. Then it's just a matter of recording with Audacity or whatever. DIY is fun!

I checked, @jmdesignz2 and you can get a Focusrite Scarlett Solo 3rd gen on Amazon for $110. No potential divider needed afaict as it does +22dBu at full scale. Plus one TRS cable with one connector looped off to connect the speaker signal to its line input. Connect it to your computer with USB. You'll be in the measuring club! Amir often promotes good measurement posts to ASR home page.

 

[jmdesignz2]

My LM4562 sounds best when its full moon.

I have also noticed last time when we had a blood moon, i swapped my Bursons 7 Classics into the buffer and boy oh boy did it sound spacious and precise! I was listening to my special Hans Zimmer Orchestra Vinyl recording played over my CD-ROM PC.
You could feel and see all the diffrent type of fingers playing the instruments, you could actually tell their skin colour, some of them were white, some of them were yellow, some were black, some were bald, some were humping, some slept the night before bad, some havnt eaten for 3 days, some needed to go to bathroom, some were already going, some had their nails done.

It was night and day! Space in Time! Finger in Rectum!

Just try it!

This is funny

 

[jmdesignz2]

I checked, @jmdesignz2 and you can get a Focusrite Scarlett Solo 3rd gen on Amazon for $110. No potential divider needed afaict as it does +22dBu at full scale. Plus one TRS cable with one connector looped off to connect the speaker signal to its line input. Connect it to your computer with USB. You'll be in the measuring club! Amir often promotes good measurement posts to ASR home page.

You suggested “Connect the speaker signal to (Scarlett solo) line input”

Won’t this burn up the Scarlett solo?

 

[jmdesignz2]

I checked, @jmdesignz2 and you can get a Focusrite Scarlett Solo 3rd gen on Amazon for $110. No potential divider needed afaict as it does +22dBu at full scale. Plus one TRS cable with one connector looped off to connect the speaker signal to its line input. Connect it to your computer with USB. You'll be in the measuring club! Amir often promotes good measurement posts to ASR home page.

Even if this doesn’t burn up the solo this how does this account for the speakers actual acoustic output?

It also introduces another device with its associated characteristics

Have you actually done this yourself?

 

[solderdude]

how does this account for the speakers actual acoustic output?

The acoustical output of speakers is solely determined by the applied voltage (output signal of the amp).

The amp in question is load sensitive so when you would record the electrical output with the speakers connected it should be O.K.

The Solo is not good enough for this experiment when the goal is to prove the difference in electrical output.
It is good enough for the TPA3255 and to record 'changes in sound' but not good enough as a measurement device for the op-amps.