Replace OP amps. Completely pointless, or not?

[DanielT]

Why do so many OPs change amps in, for example, the amplifier AIYIMA A07 TPA3255?

What's the point of that? Does not modern OPs amps amplify the signal completely linear straight(if the construction they sit in is well constructed,
and made to fit OP amp X)? Do not modern OP amps have a distortion level far, I mean really FAR below the audible? What the hell is the difference in sound that those who change claim to hear? Is it just imagination or have I missed something now?

Tips for those who have a friend who can help. Just to test. OP amps are not expensive. Ask your friend to change them in, for example, your Aiyima BUT you will not find out when and if he has done so. It is entirely up to your friend to do, or not to do. Then in time, your friend will ask you if you heard, noticed any difference in the sound.

Variant two. Ask your friend to paste small notes on a number of OP amps. You do not know which OP amp is which. Then switch and listen. Also ask your friend to number differently even though some are the same OP amp.

I say good luck hearing any difference. I think those who test the above will not hear any difference. Personally, I had bought something other than the few money op amps cost. Pizza for example. Put on the bandage and ask your friend to buy some different pizza varieties and blind test. In any case, it's yummy ... You would get something positive from such a test.

Attached files, data from Texas instruments and Wikipedia regarding distortion levels regarding OP amp NE5532 and LM4562.Change from NE5532 to LM4562 there those who did just that. Why?

NE5532 - Wikipedia

en.wikipedia.org

 

[audio2design]

You will get a much different answer to that question here to on a subjective sight. On a subjective sight they based the results on knowing exactly the change and never blind testing.

I have run into circuits where the gain was high and the distortion rose at high frequency because the op-amp did not have enough gain-bandwidth to maintain distortion at low levels.

More bandwidth product could also help if there is excessive power supply ripple, but we are talking poor design at this point.

I could see potential benefit in a differential configuration where GBW can be a useful tool. Then again, you could screw it up completely.

 

[Tangband]

Why do so many OPs change amps in, for example, the amplifier AIYIMA A07 TPA3255?

What's the point of that? Does not modern OPs amps amplify the signal completely linear straight(if the construction they sit in is well constructed,
and made to fit OP amp X)? Do not modern OP amps have a distortion level far, I mean really FAR below the audible? What the hell is the difference in sound that those who change claim to hear? Is it just imagination or have I missed something now?

Tips for those who have a friend who can help. Just to test. OP amps are not expensive. Ask your friend to change them in, for example, your Aiyima BUT you will not find out when and if he has done so. It is entirely up to your friend to do, or not to do. Then in time, your friend will ask you if you heard, noticed any difference in the sound.

Variant two. Ask your friend to paste small notes on a number of OP amps. You do not know which OP amp is which. Then switch and listen. Also ask your friend to number differently even though some are the same OP amp.

I say good luck hearing any difference. I think those who test the above will not hear any difference. Personally, I had bought something other than the few money op amps cost. Pizza for example. Put on the bandage and ask your friend to buy some different pizza varieties and blind test. In any case, it's yummy ... You would get something positive from such a test.

Attached files, data from Texas instruments and Wikipedia regarding distortion levels regarding OP amp NE5532 and LM4562.Change from NE5532 to LM4562 there those who did just that. Why?

NE5532 - Wikipedia

en.wikipedia.org

View attachment 156675View attachment 156676

In the case of Aiyima a04 ( I have two of them ) it is very clear that the sound quality gets better with LM 4562 instead of NE5532. It measures better to, with LM4562, but the difference is much smaller than the sound differences.
I can easily compair them , one with NE5532 and the other with LM 4562.
Many non- believers has been on visit and they all can hear the sound differences.
Aiyima a04 with LM4562 is more dynamic, goes deeper in the bass and sound clearer.

Having LM4562 in both amplifiers and they start to sound the same.

You have to try it yourself to hear the difference, because the measurement advantage is very small, so it should be non-audible , but it is not.

Here in sweden we have also investigated the ne5532 because there was rumours that it was a fake one in the Aiyima a04. I sent my original NE5532 to an hificonstructor and he did measurements , showing that the Aiyima a04 op amps was not fake.

 

[DanielT]

In the case of Aiyima a04 ( I have two of them ) it is very clear that the sound quality gets better with LM 4562 instead of NE5532. It measures better to, with LM4562, but the difference is much smaller than the sound differences.
I can easily compair them , one with NE5532 and the other with LM 4562.
Many non- believers has been on visit and they all can hear the sound differences.
Aiyima a04 with LM4562 is more dynamic, goes deeper in the bass and sound clearer.

Having LM4562 in both amplifiers and they start to sound the same.

You have to try it yourself to hear the difference, because the measurement advantage is very small, so it should be non-audible , but it is not.

Did you know which OP amp you were listening to or was it done blindly?

 

[Tangband]

Did you know which OP amp you were listening to or was it done blindly?

Yes, we have been using a volt measurement toole at the loudspeaker terminals to get the amplifiers exactly the same in output. The sound differences was very clear.
For me its clear evidence that LM4562 is a very good op amp.

I have also tried opa1642, 1612 and 2134, but they are all slightly inferior to lm4562 soundwise in Aiyima a04.

 

[antcollinet]

I would agree, that if there is an audible difference it will come form gain bandwidth. Especially in a design with missing or poor compensation.

 

[antcollinet]

Here are some measurements. EG up to 20dB difference in SINAD:

Objective Guide to Op-Amp Rolling - Part 1

As per moderator, here is full article from the site: Objective Guide to Op-Amp Rolling - Part 1 July 30, 2021 Op-Amp Test Board This blog article/post is a deep dive into currently available 8-pin DIP dual op-amps, for those that like to swap op-amps in their designs and/or DIY projects. The...

www.audiosciencereview.com

 

[DanielT]

Yes, we have been using a volt measurement toole at the loudspeaker terminals to get the amplifiers exactly the same in output. The sound differences was very clear.
For me its clear evidence that LM4562 is a very good op amp.

I have also tried opa1642, 1612 and 2134, but they are all slightly inferior to lm4562 soundwise in Aiyima a04.

Good that you compared with the same output but did you know which OP amp you listened to or not? If it was a blind test, how did you do it? Feel free to tell us about the method, how you performed it. I'm curious.

 

[DanielT]

In addition to replacing components in the amplifier, it MAY make a difference to the sound. For example, switching to larger (uF) electrolytic capacitors in power supply, perhaps. BUT as a happy amateur just to pop in fatter electrolytic capacitors at random I would not do that. An amplifier is designed as a whole, with other capacitors, transformer, transistors, etc. To then replace one part (with new values) without taking into account the whole of the construction, well ... hm ... I'm skeptical.

How does it work with OP amps? Is it just to pop in different at random? in the case of Aiyima, have not the constructors of the same optimized the amplifier with just OP amp X in mind?

Incidentally, to recap old amplifiers with worn out capacitors there, however, I think it can make audible differences.

Edit:
Recap amplifier. Like on a boat replacing an old outboard motor that has lost power. Then you can possibly put on a more powerful one. Maybe. Depends on the construction of the boat. ...and your nerves .... and your self-preservation drive

 

[DanielT]

Here are some measurements. EG up to 20dB difference in SINAD:

Objective Guide to Op-Amp Rolling - Part 1

As per moderator, here is full article from the site: Objective Guide to Op-Amp Rolling - Part 1 July 30, 2021 Op-Amp Test Board This blog article/post is a deep dive into currently available 8-pin DIP dual op-amps, for those that like to swap op-amps in their designs and/or DIY projects. The...

www.audiosciencereview.com

Aha,Interesting. Even though I am skeptical about changing OP amp, it is of course VERY interesting IF you can change and hear the difference. OP amps cost almost nothing.

 

[DanielT]

Thanks everyone so much for the answers and input. In any case, I think this is interesting and exciting.
We will see if there are more people who give their views on the matter.

 

[antcollinet]

Personally I'd not bother. Even if I can hear a difference, it's only going to be 50:50 that I prefer the difference.

And even if I prefer it, it probably won't be sufficient of a preference to be worth caring about.

Finally - I'd probably hear more of a difference (preferred or not) by moving my head 30cm in my listening room.

 

[Tangband]

In addition to replacing components in the amplifier, it MAY make a difference to the sound. For example, switching to larger (uF) electrolytic capacitors in power supply, perhaps. BUT as a happy amateur just to pop in fatter electrolytic capacitors at random I would not do that. An amplifier is designed as a whole, with other capacitors, transformer, transistors, etc. To then replace one part (with new values) without taking into account the whole of the construction, well ... hm ... I'm skeptical.

How does it work with OP amps? Is it just to pop in different at random? in the case of Aiyima, have not the constructors of the same optimized the amplifier with just OP amp X in mind?

Incidentally, to recap old amplifiers with worn out capacitors there, however, I think it can make audible differences.

Edit:
Recap amplifier. Like on a boat replacing an old outboard motor that has lost power. Then you can possibly put on a more powerful one. Maybe. Depends on the construction of the boat. ...and your nerves .... and your self-preservation drive

Aiyima themselves now recommends and offers replacement of ne5532 to lm4562 in the a07 model.
PMA have done measurements to, and the lm4562 measures slightly better than ne5532 in Aiyima a07 . But the difference is small.

 

[Tangband]

Personally I'd not bother. Even if I can hear a difference, it's only going to be 50:50 that I prefer the difference.

And even if I prefer it, it probably won't be sufficient of a preference to be worth caring about.

Finally - I'd probably hear more of a difference (preferred or not) by moving my head 30cm in my listening room.

In the case of my two Aiyima a04 and switching between ne5532 amp to lm4562 amplifier, the difference soundwise is clearly bigger than moving your head 30 cm in the listening room.
The uppgrade to lm4562 is a no-brainer if youre interested in hifi, and clearly worth 5 dollars . Its more fun to listen to the music. Do it and you will be surprised.

 

[antcollinet]

Perhaps - but I don't have that amp, so I can't.

 

[pozz]

upgrade

Avoid thinking of audio in these terms. It will only cost money.

Aiyima themselves now recommends and offers replacement of ne5532 to lm4562 in the a07 model.
PMA have done measurements to, and the lm4562 measures slightly better than ne5532 in Aiyima a07 . But the difference is small.View attachment 156697View attachment 156698

These graphs say nothing useful. Please don't misuse the information given you on pointless listening tests and poorly considered advice.

 

[Tangband]

Avoid thinking of audio in these terms. It will only cost money.

These graphs say nothing useful. Please don't misuse the information given you on pointless listening tests and poorly considered advice.

In this case there is no contradiction. The lm4562 is technically proven better than ne5532 in this amplifier. In my subjective opinion , the lm4562 also sound clearly better, and Ím free to say that.
So my advice might be useless for you, but not for others.

 

[audio2design]

Aiyima a04 with LM4562 is more dynamic, goes deeper in the bass and sound clearer.

My BS meter went off. I noticed repeated avoidance of "did you test blind"? You also lost me with deeper bass (and dynamic). Unless the circuit is improperly implemented, i.e. AC coupled with inadequate capacitance, no way that op-amp switch makes the bass deeper. None at all.

 

[Tangband]

My BS meter went off. I noticed repeated avoidance of "did you test blind"? You also lost me with deeper bass (and dynamic). Unless the circuit is improperly implemented, i.e. AC coupled with inadequate capacitance, no way that op-amp switch makes the bass deeper. None at all.

Well, thats only my perceived differences between ne5532 and lm4562 in this amplifier, when listening to music. I know they measure almost the same with static , non-music testtones.

 

[audio2design]

Tangbands graphs show a low level power frequency spike, this comes down likely to poor implementation, though a better amp may alleviate. Then there is what looks like a power supply spike 3x50. Looks like the unit was powered by 50hz bench supply but used in a 50hz environment. Who knows what ground loops are there.