Does Op-amp Rolling Work?

[solderdude]

My ears are the only tools I have around here to measure this, I believe. What kind of gear do I need for this?

Using your ears is fine.
You do not even need special gear to do this properly.
No ABX box needed either.

You will need a helper that can swap op-amps and plug and unplug the gear without you knowing what is in the (pre)amp and a spend a lot of time (for statistical relevance) and again ... above all ... you can NOT know what op-amp is in there when listening so NO visual clues either. You will only be using your trustworthy ears that way.

 

[Audionaut]

Because these models learn from vast amounts of internet data, including social networks, their outputs reflect the biases, opinions, and inaccuracies present in that data.

In other words, the same principles of learning that apply to humans, including the behavior in Internet forums, including ASR

 

[pma]

I just rolled the op-amps in my Aiyima A07 to LME49720NA and immediately noticed a subjective improvement. The sound feels less dry and more musical, I am using a 80 Hz high pass filter on my speakers, though.

You are only repeating something you have found somewhere. Contrary to you, I have measured AIYIMA A07 with NE5532, LME49720 and OPA2134. You can find it here with the search engine. There are almost no measurable differences in A07 plots when these opamps are swapped. Everything is masked by the TPA3255. No audible differences. You are only describing your subjective impressions without a single proof.

@olds1959special , I have made my homework and re-measured AIYIMA A07 with NE5532, LME49720 and OPA2134. My measuring system has been improved since the time of my first measurements of the A07. However, no breakthrough findings. I measured the A07 supplied from 27Vdc SMPS and loaded with 4R7/200W resistor. Below are the results.

1. THD vs. output voltage with 3 opamps:

It can be seen that the plots are almost identical. BTW, very good result.

2. THD vs. frequency at 20W/4.7ohm with @BW48kHz

Again, the plots are identical, only at very low frequencies NE5532 is lower due to its lower noise.
I do not like that result very much, however it is typical for TPA3255 class D amps measured with BW48kHz. At this point I want to emphasize that harmonic distortion is not a problem of this and similar amplifiers. The big problem is their very very high output impedance at high frequencies, due to output LC filter impedance. This makes their sound dependable on the complex impedance of the speaker used and they are then distinguishable in a DBT test from amplifiers with load invariant frequency response. That's a cost of the ultra low cost design.



P.S.: I would like to add that the NE5532 is a better choice for AIYIMA A07 than the LME49720. The reason is that 5532 has lower input current noise than 49720. The thdfreq plot of 49720 x 5532 is similar to 2134 x 5532 plot. 2134 has higher input voltage noise than 5532. Once again, 5532 is the winner due its versatility.

 

[aagstn]

The sound feels less dry and more musical

I've been listening to music over half a century and still have no idea what statements like this mean. Music can sound more moist? I'm really not trying to be negative towards the poster. I'm sure they felt they heard an improvement and that is fine. I just don't see how a subjective review with ambiguous language helps me make a decision since I have neither the same ears or listening room. Not to mention no concept for what dry music sounds like or what more musical or more dynamic or more soundstage would even be. At least with measurements I have a baseline to know that if I setup my room correctly something should be flat or not have audible noise and distortion.

 

[Bruce Morgen]

I've been listening to music over half a century and still have no idea what statements like this mean. Music can sound more moist? I'm really not trying to be negative towards the poster. I'm sure they felt they heard an improvement and that is fine. I just don't see how a subjective review with ambiguous language helps me make a decision since I have neither the same ears or listening room. Not to mention no concept for what dry music sounds like or what more musical or more dynamic or more soundstage would even be. At least with measurements I have a baseline to know that if I setup my room correctly something should be flat or not have audible noise and distortion.

In the pro recording world the word "dry" is used to indicate a track that has little or no reverb, echo or some such, IOW more or less a replica of what the microphone "hears" from the performer, whereas "wet" indicates a track that has been deliberately enhanced by some effect of that sort. I don't think those terms apply usefully to a high fidelity (which means "great faithfulness" -- AKA "transparency" -- to the content of the source media) playback system's performance.

 

[olds1959special]

I've been listening to music over half a century and still have no idea what statements like this mean. Music can sound more moist? I'm really not trying to be negative towards the poster. I'm sure they felt they heard an improvement and that is fine. I just don't see how a subjective review with ambiguous language helps me make a decision since I have neither the same ears or listening room. Not to mention no concept for what dry music sounds like or what more musical or more dynamic or more soundstage would even be. At least with measurements I have a baseline to know that if I setup my room correctly something should be flat or not have audible noise and distortion.

Disclaimer: I'm being unscientific! I think what I noticed was better/deeper "soundstage". I would describe this as the quality of the amp to create a sense of dimension in the music instead of just feeling flat. This is just a subjective description of course, but often used by audiophiles trying to describe qualities of particular gear. Some tube amps are known for creating this feeling of space in the music.

 

[solderdude]

but ... is it the amp or is it memorex ?

 

[ckernel8]

Disclaimer: I'm being unscientific! I think what I noticed was better/deeper "soundstage". I would describe this as the quality of the amp to create a sense of dimension in the music instead of just feeling flat. This is just a subjective description of course, but often used by audiophiles trying to describe qualities of particular gear. Some tube amps are known for creating this feeling of space in the music.

Why would you attribute this to the amp though?

 

[ckernel8]

I'm not really "into" op-amp rolling. I'd much rather have a device that sounded great from the get go. But I was tempted to try this after reading what google AI said about these two op-amps:

The LME49720NA offers superior audio fidelity with extremely low noise and distortion, making it ideal for high-end audio, while the NE5532 is a versatile, cost-effective op-amp for general audio applications, suitable for a wide range of tasks but with lower performance parameters than the LME49720NA. The LME49720NA is a more advanced, higher-cost component designed for premium audio, whereas the NE5532 provides a balanced performance and cost for more general use.

Choose the LME49720NA for:

• Highest Audio Quality:
  If your application demands the absolute best sound with minimal noise and distortion, such as in premium preamplifiers, DACs, or headphone amplifiers.
  
  
• Professional and Critical Audio:
  Where maintaining the highest signal fidelity is crucial, the LME49720NA is the preferred choice.
  
  
• Driving Complex Loads:
  It can easily handle and drive loads as high as 600Ω and complex capacitive loads.

Choose the NE5532 for:

• Versatility:
  For general audio circuits, mixers, filters, tone controllers, and other non-specialized audio applications.
• Cost-Effectiveness:
  If you need acceptable audio performance without the higher cost of premium components, the NE5532 provides a good balance.
• Balancing Performance and Budget:
  It offers a solid, cost-effective solution for everyday audio projects where top-tier performance isn't strictly required.

Key Differences at a Glance

• Performance: The LME49720NA significantly outperforms the NE5532 in noise, bandwidth, and total harmonic distortion (THD).
  
  
• Cost: The LME49720NA is significantly more expensive than the NE5532.
  
  
• Application: The LME49720NA is for high-fidelity, premium applications, while the NE5532 is for a broader range of audio and general-purpose tasks.

I tried this op-amp in the Fosi P4 and the results were not good (extremely thin sound), but since people were recommending the LM4562NA for the Aiyima A70 mono, I thought I'd try the LME49720NA since I had them and they are supposed to the same.

The problem is AI is tainted overwhelmingly with forum twaddle that supports this nonsense. That's the real problem with AI, unless you explicitly tell it to steelman the opposite theory, it will only ever be a confirmation bias machine.

 

[JRowland]

In the pro recording world the word "dry" is used to indicate a track that has little or no reverb, echo or some such, IOW more or less a replica of what the microphone "hears" from the performer, whereas "wet" indicates a track that has been deliberately enhanced by some effect of that sort. I don't think those terms apply usefully to a high fidelity (which means "great faithfulness" -- AKA "transparency" -- to the content of the source media) playback system's performance.

I always thought wet meant close mic'd, where you hear the spit moving? Like this song

 

[Audionaut]

Music can sound more moist?

Moist music

Dry music

 

[RexrothPigeon]

"I said he used to be a piece of shit. He's not anymore. I'm not anymore. Glass House. White IEMs. Live for New Year's Eve. Sloppy speakers at Truffoni's. Big coaxial driver with water dumped all over it, water splashing around the listening room, makes the night SO MUCH more fun. After the club go to Truffoni's for sloppy speakers. They'd say; 'no sloppy speakers' but they can't stop you from buying a speaker and a glass of water, before you knew it we were dumping that water on those speakers! The salesmen were coming to try and snatch em up, we had to listen as fast as we could! OHHH I MISS THOSE NIGHTS, I WAS A PIECE OF SHIT THOUGH."

 

[Mnyb]

Using your ears is fine.
You do not even need special gear to do this properly.
No ABX box needed either.

You will need a helper that can swap op-amps and plug and unplug the gear without you knowing what is in the (pre)amp and a spend a lot of time (for statistical relevance) and again ... above all ... you can NOT know what op-amp is in there when listening so NO visual clues either. You will only be using your trustworthy ears that way.

for best effect the helper should not know either paint tape over the markings with an A and a B , can be done by a third helper ..

Or just trust the freaking measurement's and enjoy the music if all kinds of problems are under the human treashold ( for properly working OP's fit for the circuit ) why bother

 

[Mnyb]

Disclaimer: I'm being unscientific! I think what I noticed was better/deeper "soundstage". I would describe this as the quality of the amp to create a sense of dimension in the music instead of just feeling flat. This is just a subjective description of course, but often used by audiophiles trying to describe qualities of particular gear. Some tube amps are known for creating this feeling of space in the music.

"Soundstage" is a kind of tell here ? it's not a property amps normally can have they are to simple . It would require DSP or gross fr response error combined with some speakers to maybe shift something a little bit, but manipulate the spatiality of the track no i don't think an amp or DAC can do that .

These products are putting out simple voltages with very few characteristics , the voltage goes up and down over time its nothing more fancy than that, and it has no memory or knowledge. It's actually not music yet that happens in your head when the soundwaves hit you.

Both analog and digital signals are information about the music they are not the music . Giving hifi musical word salad attribution is akin to anthropomorphizing animal behavior or computer behavior ( my PC was grumpy this morning ) .

 

[Audionaut]

I'm being unscientific! I think what I noticed was better/deeper "soundstage". I would describe this as the quality of the amp to create a sense of dimension in the music instead of just feeling flat. This is just a subjective description of course, but often used by audiophiles trying to describe qualities of particular gear

Don't let it take the fun out of experimenting.

However, I don't think ASR is the best audience for this kind of sound description. But it might be the right challenge to find out if you can hold your own rhetorically.

Warming up to ASR with subjectively perceived sound descriptions is a bit masochistic in my view, and perhaps a bit like philosophizing about the merits of the vegan lifestyle in a steakhouse.

You can do it, but it has little chance of success and is not really recommendable.

 

[Haskil]

I'm not really "into" op-amp rolling. I'd much rather have a device that sounded great from the get go. But I was tempted to try this after reading what google AI said about these two op-amps:

The LME49720NA offers superior audio fidelity with extremely low noise and distortion, making it ideal for high-end audio, while the NE5532 is a versatile, cost-effective op-amp for general audio applications, suitable for a wide range of tasks but with lower performance parameters than the LME49720NA. The LME49720NA is a more advanced, higher-cost component designed for premium audio, whereas the NE5532 provides a balanced performance and cost for more general use.

Choose the LME49720NA for:

• Highest Audio Quality:
  If your application demands the absolute best sound with minimal noise and distortion, such as in premium preamplifiers, DACs, or headphone amplifiers.
  
  
• Professional and Critical Audio:
  Where maintaining the highest signal fidelity is crucial, the LME49720NA is the preferred choice.
  
  
• Driving Complex Loads:
  It can easily handle and drive loads as high as 600Ω and complex capacitive loads.

Choose the NE5532 for:

• Versatility:
  For general audio circuits, mixers, filters, tone controllers, and other non-specialized audio applications.
• Cost-Effectiveness:
  If you need acceptable audio performance without the higher cost of premium components, the NE5532 provides a good balance.
• Balancing Performance and Budget:
  It offers a solid, cost-effective solution for everyday audio projects where top-tier performance isn't strictly required.

Key Differences at a Glance

• Performance: The LME49720NA significantly outperforms the NE5532 in noise, bandwidth, and total harmonic distortion (THD).
  
  
• Cost: The LME49720NA is significantly more expensive than the NE5532.
  
  
• Application: The LME49720NA is for high-fidelity, premium applications, while the NE5532 is for a broader range of audio and general-purpose tasks.

I tried this op-amp in the Fosi P4 and the results were not good (extremely thin sound), but since people were recommending the LM4562NA for the Aiyima A70 mono, I thought I'd try the LME49720NA since I had them and they are supposed to the same.

The 5532 is widely used in many very very expensive professional mixing consoles used in studios to record records...

The AI forgot...

(Note that for fun, I asked the AI to tell me who I was... It found a qualification I didn't have and forgot some. So I asked it to correct that in the exchanges... It said I was known for being a jazz specialist, among other types of music... And I don't have any namesakes...)

 

[SnakeLord]

Moist music

View attachment 478490

Dry music


View attachment 478491

Which is a perfect example of what music does to all of us. It is addressing our feelings on the lowest level and since we dont know exactly how and why we start to search for the "magic" behind it, comming up with this religious/fananatic type of nonesense, an complete audiofoolery lexicon being immune to arguments and facts while snake oil sellers are making use of it.

Fun fact: If you have a bunch of Opamps to roll and try to wright down the subtile diffrences using the audiofoolery lexicon, at some point you just come to the conclusion, that all of them sound the same

 

[olds1959special]

@olds1959special , I have made my homework and re-measured AIYIMA A07 with NE5532, LME49720 and OPA2134. My measuring system has been improved since the time of my first measurements of the A07. However, no breakthrough findings. I measured the A07 supplied from 27Vdc SMPS and loaded with 4R7/200W resistor. Below are the results.

1. THD vs. output voltage with 3 opamps:

View attachment 478287

It can be seen that the plots are almost identical. BTW, very good result.

2. THD vs. frequency at 20W/4.7ohm with @BW48kHz

View attachment 478289

Again, the plots are identical, only at very low frequencies NE5532 is lower due to its lower noise.
I do not like that result very much, however it is typical for TPA3255 class D amps measured with BW48kHz. At this point I want to emphasize that harmonic distortion is not a problem of this and similar amplifiers. The big problem is their very very high output impedance at high frequencies, due to output LC filter impedance. This makes their sound dependable on the complex impedance of the speaker used and they are then distinguishable in a DBT test from amplifiers with load invariant frequency response. That's a cost of the ultra low cost design.

View attachment 478290 View attachment 478291

P.S.: I would like to add that the NE5532 is a better choice for AIYIMA A07 than the LME49720. The reason is that 5532 has lower input current noise than 49720. The thdfreq plot of 49720 x 5532 is similar to 2134 x 5532 plot. 2134 has higher input voltage noise than 5532. Once again, 5532 is the winner due its versatility.

I changed back to NE5532. Thanks!

 

[ThsM]

Moist music

View attachment 478490

Dry music


View attachment 478491

That makes sense!
Thanks for clarification

 

[testp]

Dune has the best dry music