Replace OP amps. Completely pointless, or not?

[DanielT]

Guys, just leave tangband alone and have pity on him.
- He's wasting his time
- He would never pass a blind test
- Listening to 20 minutes of music in a row for comparison is nonsense
- Experienced listeners need 5-10 seconds, after 30 seconds it is no longer possible to verify differences
- The Aiyima a04 is completely unsuitable for OPAmp rolling
- All the circuitry around the OPAmp is cheap and buggy
- The SE to Balanced circuit with inverted OPAmps connected in series also generates time errors.
- The power supply with one-sided 12v is even worse
- 0-12v with artificial ground somewhere around 6v
- Cheap switching regulator to generate the 12v with bad filtering
- Extremely dirty 12v supply, just measure it

I even believe that the OPAmps sound different in the Aiyima a04. But that will rather be the effects of mismatches and wrong working environments for the rolled OPAmps. Just go with an oscilloscope.
The LM4562 in particular is known to oscillate in such circuits. This often leads to a preference.
There are reasons why the Topping PA5 sounds so much better and cleaner than all the cheap TPA235X units. All the shortcomings listed above do not exist.

Then maybe Tangband isn't imagining things when he claims there are audible differences when he rolls his OP amps?

You mention Topping PA5. Probably a great amp, as long as it works:

Poll for Topping PA5 owners only please.

Poll for PA5 owners to report product defects. Discussion for any solutions. I think it would be useful to get a handle on some numbers to estimate just how wide spread the issues are. Addendum: Here is Topping's response to the PA5 issues...

audiosciencereview.com

Maybe Topping TP RA3 can be an alternative to Topping PA5, if you accept the PA look.

TP RA3 Rackmount Amplifier Review

This is a review and detailed measurements of the TP (Topping) RA3 stereo balanced rackmount amplifier. It was sent to me by the company and costs US $229. Yes, this is a new sub-brand from Topping. I quite like it. The large and highly visible volume level is as gorgeous to look at as it is...

audiosciencereview.com

 

[Killingbeans]

Then maybe Tangband isn't imagining things when he claims there are audible differences when he rolls his OP amps?

Possibly. But then he's just confusing difference with superiority. The other side of the same pointless coin.

 

[DanielT]

Possibly. But then he's just confusing difference with superiority. The other side of the same pointless coin.

Hm, that seems like a pretty haphazard method of possibly getting some other kind of sound. It might be different, but let's say I replaced various resistors and capacitors with different values in an amplifier. Replaced them randomly here and there. In the end, if the amplifier doesn't break, stops working, then maybe I created some other type of sound, but I wouldn't say that it depends on the quality of these resistors or capacitors in themselves.

 

[HarmonicTHD]

Then maybe Tangband isn't imagining things when he claims there are audible differences when he rolls his OP amps?

You mention Topping PA5. Probably a great amp, as long as it works:

Poll for Topping PA5 owners only please.

Poll for PA5 owners to report product defects. Discussion for any solutions. I think it would be useful to get a handle on some numbers to estimate just how wide spread the issues are. Addendum: Here is Topping's response to the PA5 issues...

audiosciencereview.com

Maybe Topping TP RA3 can be an alternative to Topping PA5, if you accept the PA look.

TP RA3 Rackmount Amplifier Review

This is a review and detailed measurements of the TP (Topping) RA3 stereo balanced rackmount amplifier. It was sent to me by the company and costs US $229. Yes, this is a new sub-brand from Topping. I quite like it. The large and highly visible volume level is as gorgeous to look at as it is...

audiosciencereview.com

Again a simple THD test and FR sweep and we wouldn’t be speculating about what he heard (or probably didn’t).

 

[Roland68]

Then maybe Tangband isn't imagining things when he claims there are audible differences when he rolls his OP amps?

You mention Topping PA5. Probably a great amp, as long as it works:

Poll for Topping PA5 owners only please.

Poll for PA5 owners to report product defects. Discussion for any solutions. I think it would be useful to get a handle on some numbers to estimate just how wide spread the issues are. Addendum: Here is Topping's response to the PA5 issues...

audiosciencereview.com

Maybe Topping TP RA3 can be an alternative to Topping PA5, if you accept the PA look.

TP RA3 Rackmount Amplifier Review

This is a review and detailed measurements of the TP (Topping) RA3 stereo balanced rackmount amplifier. It was sent to me by the company and costs US $229. Yes, this is a new sub-brand from Topping. I quite like it. The large and highly visible volume level is as gorgeous to look at as it is...

audiosciencereview.com

Yes, it can make it sound more brilliant, emphasized and higher definition, but it's just being added and of course it's not real.

The user @gamerpaddy was kind enough to create a solution for the PA5 that can help any affected device.
Topping PA5 fix - D01 Module Replacement for everyone

 

[Killingbeans]

Hm, that seems like a pretty haphazard method of possibly getting some other kind of sound. It might be different, but let's say I replaced various resistors and capacitors with different values in an amplifier. Replaced them randomly here and there. In the end, if the amplifier doesn't break, stops working, then maybe I created some other type of sound, but I wouldn't say that it depends on the quality of these resistors or capacitors in themselves.

Yes, op-amp rolling always makes me think of this:

 

[erintse]

I just compared LM4562 vs NE5532 for your reference. Hope it helps.

Aspect​	LM4562​	NE5532​
Appearance	Dual op amp package	Dual op amp package
Parameters
Supply Voltage	±2.5V to ±17V	±5V to ±22V
Gain BW Product	55 MHz	10 MHz
Input Offset V	1.5 mV (max)	5 mV (max)
Input Noise V	3.9 nV/√Hz (typ)	12 nV/√Hz (typ)
Slew Rate	20 V/µs (typ)	9 V/µs (typ)
Performance
Audio Quality	High performance	Decent performance
Distortion	Low	Acceptable
Noise	Low	Acceptable
Applications
High-End Audio	Preamplifiers, DACs,	General-purpose
Equipment	Headphone Amps	Audio Applications
Versatility	Lower flexibility	Wide versatility
Cost	Higher cost	Cost-effective

 

[solderdude]

Yes, ALL opamps measure differently (specs). That does not mean they measure very differently in a circuit. It also does not mean the differences are audible either.

 

[erintse]

Yes, ALL opamps measure differently (specs). That does not mean they measure very differently in a circuit. It also does not mean the differences are audible either.

You are right

 

[MaxwellsEq]

I just compared LM4562 vs NE5532 for your reference. Hope it helps.

Aspect​	LM4562​	NE5532​
Appearance	Dual op amp package	Dual op amp package
Parameters
Supply Voltage	±2.5V to ±17V	±5V to ±22V
Gain BW Product	55 MHz	10 MHz
Input Offset V	1.5 mV (max)	5 mV (max)
Input Noise V	3.9 nV/√Hz (typ)	12 nV/√Hz (typ)
Slew Rate	20 V/µs (typ)	9 V/µs (typ)
Performance
Audio Quality	High performance	Decent performance
Distortion	Low	Acceptable
Noise	Low	Acceptable
Applications
High-End Audio	Preamplifiers, DACs,	General-purpose
Equipment	Headphone Amps	Audio Applications
Versatility	Lower flexibility	Wide versatility
Cost	Higher cost	Cost-effective

Thanks. You have demonstrated that it's a risky, unmeasured and unpredictable outcome when you swap one Op-Amp for another.

There's no guarantee that taking out an existing Op-Amp and plugging in an intrinsically quieter, larger gain-bandwidth product will improve matters, in fact, the circuit is just as likely to be unstable with incorrect DC values resulting in more noise and greater distortion.

 

[Speedskater]

Yes, ALL opamps measure differently (specs). That does not mean they measure very differently in a circuit. It also does not mean the differences are audible either.

Conversely, not all op-amps are suitable for all circuits. (not even close)

 

[egellings]

Yes, ALL opamps measure differently (specs). That does not mean they measure very differently in a circuit. It also does not mean the differences are audible either.

Once the local feedback is applied to reduce the huge gain of the op amps to that needed by the audio circuits they will be used in, they'll all do an excellent job of faithfully tracking the input signal. Sound should (it had better be!) identical.

 

[Barrelhouse Solly]

This is a hobbyist thing. When I was 18 I got a job in a McDonald's. Most of the guys I worked with--they didn't hire women in 1964--were hot rodders. I got introduced to a huge hobbyist world very similar to audio. People would argue endlessly about the fine points of intake and exhaust manifolds and carburetors. There were Ford 427 loyalists and Mopar hemi 426 loyalists. Rear end gear ratios were a big topic. Rolling op amps is like changing carburetors. If you're into it, it's fun. Who knows, it might get you a few tenths of a second in a quarter mile. That's the essence of this kind of hobby. A good deal of the fun is the tinkering.

 

[egellings]

This is a hobbyist thing. When I was 18 I got a job in a McDonald's. Most of the guys I worked with--they didn't hire women in 1964--were hot rodders. I got introduced to a huge hobbyist world very similar to audio. People would argue endlessly about the fine points of intake and exhaust manifolds and carburetors. There were Ford 427 loyalists and Mopar hemi 426 loyalists. Rear end gear ratios were a big topic. Rolling op amps is like changing carburetors. If you're into it, it's fun. Who knows, it might get you a few tenths of a second in a quarter mile. That's the essence of this kind of hobby. A good deal of the fun is the tinkering.

Agree! I am also an inveterate tinkerer, even though I am an EE by profession (now retired).

 

[JSmith]

Rolling op amps is like changing carburetors.

It really isn't at all.


JSmith

 

[Ricardus]

Rolling op amps is like changing carburetors. If you're into it, it's fun. Who knows, it might get you a few tenths of a second in a quarter mile. That's the essence of this kind of hobby. A good deal of the fun is the tinkering.

Rolling opamps is NOTHING like changing carburetors. Carbs can have more fuel flow which can make more horsepower.

There is nothing in common with opamps there other than some people might find it fun. Especially when their bias makes them think it sounds "TOTALLY DIFFERENT!"

 

[DonR]

I just compared LM4562 vs NE5532 for your reference. Hope it helps.

Aspect​	LM4562​	NE5532​
Appearance	Dual op amp package	Dual op amp package
Parameters
Supply Voltage	±2.5V to ±17V	±5V to ±22V
Gain BW Product	55 MHz	10 MHz
Input Offset V	1.5 mV (max)	5 mV (max)
Input Noise V	3.9 nV/√Hz (typ)	12 nV/√Hz (typ)
Slew Rate	20 V/µs (typ)	9 V/µs (typ)
Performance
Audio Quality	High performance	Decent performance
Distortion	Low	Acceptable
Noise	Low	Acceptable
Applications
High-End Audio	Preamplifiers, DACs,	General-purpose
Equipment	Headphone Amps	Audio Applications
Versatility	Lower flexibility	Wide versatility
Cost	Higher cost	Cost-effective

Top half of table objective, bottom half subjective.

 

[MAB]

Guys, just leave tangband alone and have pity on him.
- He's wasting his time
- He would never pass a blind test
- Listening to 20 minutes of music in a row for comparison is nonsense
- Experienced listeners need 5-10 seconds, after 30 seconds it is no longer possible to verify differences
- The Aiyima a04 is completely unsuitable for OPAmp rolling
- All the circuitry around the OPAmp is cheap and buggy
- The SE to Balanced circuit with inverted OPAmps connected in series also generates time errors.
- The power supply with one-sided 12v is even worse
- 0-12v with artificial ground somewhere around 6v
- Cheap switching regulator to generate the 12v with bad filtering
- Extremely dirty 12v supply, just measure it

I even believe that the OPAmps sound different in the Aiyima a04. But that will rather be the effects of mismatches and wrong working environments for the rolled OPAmps. Just go with an oscilloscope.
The LM4562 in particular is known to oscillate in such circuits. This often leads to a preference.
There are reasons why the Topping PA5 sounds so much better and cleaner than all the cheap TPA235X units. All the shortcomings listed above do not exist.

Aside from very good technical advice, you also point out the odd psychological trap that's at work. I think it's the same thing that causes people who can't cook to buy ready-made mixes that require just one additional ingredient to make, an egg. "Just one trick" is needed to unlock the secrets of great sensations, and "just my ears" can know since performing the trick causes the person to become an instant expert, like adding a free-range egg to the cake mix somehow elevates that box of cake-mix to new heights. I see so many audiophiles desperate to be music creators; these tweaks seem to make them feel part of the creative process even when they measurably degrade the performance or the perf wasn't good to begin with... The fact that they can't hear any of the differences keeps them in a circle of confusion. I think we give too much credit when we say that these audiophiles actually hear these differences between (for instance) an oscillating opamp or elevated distortion. Just like cable-swapping, it's all ego and emotion speaking.

 

[Barrelhouse Solly]

Rolling opamps is NOTHING like changing carburetors. Carbs can have more fuel flow which can make more horsepower.

There is nothing in common with opamps there other than some people might find it fun. Especially when their bias makes them think it sounds "TOTALLY DIFFERENT!"

OK, I wasn't specific enough. I know that going from a 2 bbl to a 4 bbl or an intake manifold with multiple carb mounts can make a difference. What I was thinking of was going from one 4 bbl to another with more or less similar parts. I could have used a better example.

 

[Ricardus]

OK, I wasn't specific enough.

No amount of specificity makes this a good analogy.

In their quest to prove that changing opamps (and any other components) makes a difference, I have heard "audiophiles" compare audio to car tires, turbochargers, and now carburetors.

You can always get more ponies from cars with more gas and more air. Engines aren't amps.

Amplification is a solved problem. We have been able to design amps at the cutting edge of specs for decades. Those amps will all sound the same, unless you put in a broken opamp.