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Big test of DIP dual op-amps for audio: LM4562, NE5532, OPA2134, TL072 and LM1458

There are questions if it matters which type of op-amp is used in the audio amplifier and my answer is that it depends on circuit schematics and op-amp parameters. Some of those parameters are obvious from datasheets, but others may be quite hidden and not clear from the first view. For the test I have chosen well known dual op-amps LM4562, NE5532, LM1458 (bipolar input) and OPA2134, TL 072 (JFET input).
LM1458 is one of the first op-amps usable for audio and it is dated at sixties of the previous century. NE5532 was then a big big improvement in audio op-amps, introduced by Signetics company in 1979. LM4562 appeared in 2006 as an improvement in noise and supposed to have lower distortion than NE5532.
OPA2134 was introduced by Burr-Brown in the nineties as a lower noise and lower distortion improvement of TL072.
As far the datasheet and popular info.

When making a choice of the op-amp, we always need to know the application circuit. For the test I have chosen quite common non-inverting amplifier circuit with +6dB gain and 10k feedback resistors.

View attachment 438490

The test rig is driven from a DAC with low, 20 ohm output impedance, and loaded with 1 kohm ADC input impedance. This is quite difficult load, but as the output voltage did not exceed 3V, all the op-amps are deep in the area of allowed output current.

Measurements

For the start, I have chosen measurements of THD vs. output voltage at 1kHz and 10kHz and measurements of 13+14kHz CCIF IMD vs. output voltage. The plots are shown below:

View attachment 438493

View attachment 438494

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We can see that the LM1458 is simply unusable for audio, even at low output voltage and that we can assume it will have its own sound signature. Both JFET opamps, OPA2134 and TL072 have higher distortion than LM4562 and NE5532, in all 3 tests. The result of the old NE5532, that is slightly better than LM4562, is a small surprise to me, I have expected the opposite result.

In all cases, I have tested at least two samples of each op-amp type, to prevent random results. All the samples of the same types behaved identically within the measurement repeatability.

More tests can be done, suggestions welcome. But I will wait for the forum feedback.

All the measurements done with 96kHz sampling and 45kHz effective bandwidth.

Note: for loopback test please go to post #33
Very nice. It fits my experience too with 5532. I am testing DIP8 opamps with composite: opamp+LME48610 (diyinhk HP board, gain x2, based on TI HP, see LME49720).
It is surprising and also it surprises that TI published THD+N=0.002% for NE5532.
Although you measured only the THD part the noise of NE5532 is not so dominant to spoil your excellent perfornance to 0.002%. Hence, TI published under specs for 5532.
 
I think it was due to lower resolution of the distortion analyzers decades ago, maybe AP1?
 
Everybody on this forum is just trying to somehow prove that NE5532 is not the best opamp. Why can't we accept that there is no better opamp than NE5532.

I have accepted that there is no better opamp than ne5532 and there is no other super power in the world like China. :D
 
Everybody on this forum is just trying to somehow prove that NE5532 is not the best opamp. Why can't we accept that there is no better opamp than NE5532.
Tis is a plain nonsense, without any qualified support of the opinion posted. Go and read Douglas Self's analysis



or Samuel Groner's book on op-amp tests.
This is my final post to your comment, I am not going to continue in debate at this level.
 
I took that comment as sarcastic and meant in a joking tone. :) I've been wrong before though.
 
Tis is a plain nonsense, without any qualified support of the opinion posted. Go and read Douglas Self's analysis



or Samuel Groner's book on op-amp tests.
This is my final post to your comment, I am not going to continue in debate at this level.

D.Self still praises NE5532. Please read the conclusion copied from website.

Overall Conclusion
While some of the newer op-amps can offer lower distortion in some configurations, the veteran NE5532 holds up surprisingly well, considering it has been around since 1979 — that’s almost four decades. aX
 
I think it was due to lower resolution of the distortion analyzers decades ago, maybe AP1?
Maybe.
They could re-measure but anyway, they are measuring distortion indirectly with this 'one resistor' method by amplifying the THD(+N) by a factor of 101, so normally even AP1 is enough.
Maybe they are just lazy.
 
Everybody on this forum is just trying to somehow prove that NE5532 is not the best opamp. Why can't we accept that there is no better opamp than NE5532.

I have accepted that there is no better opamp than ne5532 and there is no other super power in the world like China. :D
It depends also what is the spot. For example the noise performance of 5532 is not as good as OPA1612 and not AD797 etc...
 
OPA2132 has 10x lower THD than OPA2134.They are not the same design.
OPA2228, 1642, 1656 which were aimed at audio market are superior to any prior design .There are though industrial and medical use op amps with better specs and higher price.
Starting from 100 ohms to 100 kohms, depending on op amps , common mode cancelling resistors were used with great results on a lot of op amps that suffer of not so great common mode distortions.
I' d like to see LM833, UPC4570 , NJM2114, NJM2043, BA1/M5218 , 5219,/5220 and NJM4559 measured for common mode distortions in unity gain followers and their performance in I/ V converter circuits after a DAC compared to NJM5534.
 
LM833 was a copy of the 5532, I dont kown which one is better
It's not actually a copy at all, more like a (lower-priced) competitor. Quoting yours truly,
A part positioned against the NE5532 at the time, though with less complex circuitry (basically a souped-up 4558 with some distortion cancellation trickery in the VAS). It fares better in terms of voltage noise (4.5 nV/√(Hz)), and common-mode distortion may still beat a TI '5532 (apparently performance has been tweaked for unity or low noninverting gain, a common usage scenario), but as the relatively modest idle current may already indicate, output loading immunity is only average, and current limiting kicks in at about +18 dBu into 600 ohms (it'll get to about +4 V into 200 ohms, the negative side is about twice as powerful). Output loading at +20 dBu is best kept no lower than 3k9 or so. Also mind input impedance nonlinearity (better than typical FET input parts but not nearly a match for a 5532 and several other good bipolars), as well as significant input bias current (500 nA typ).

Note that TI now sells two LM833 variations, one being the original NatSemi part (called "LM833-N", LM833N in DIP), the other their take on the MC33078 as discussed below (LM833P in DIP).
[And that is another design entirely.]
 
You reminded me of MC33071 which proved to be quite good for condenser and electret microphones, very low noise, lower noise than TL072 , LF353, and others in my tests.
 
I have a STEG car amplfier [Made in Italy] year is around 2007-2008 which is a highly reported car audio company.
My amplifier is an exceptional sounding one. One the best I have heard at any price point.

Surprisingly when i remove the cover. I found out that the amp uses TL072 opamps which are quite outdated.
I am still confused why this amp sound superior to anything I have heard before.
 
You reminded me of MC33071 which proved to be quite good for condenser and electret microphones, very low noise, lower noise than TL072 , LF353, and others in my tests.
What a quirky little circuit - kind of a mix of LM358, µA741 and TBA820M or something, very 1970s.

e_n = 32 nV/√(Hz), i_n = 0.22 pA/√(Hz)... that doesn't exactly make for a very favorable e_n * i_n product. Unless these specs are way off, I don't see how it could beat a TL072, 1/f noise <100 Hz possibly excepted.

The output stage also apparently is crossover distortion galore and in dire need of some Class A bias.

Are you sure it was that exact part?

I have a STEG car amplfier [Made in Italy] year is around 2007-2008 which is a highly reported car audio company.
My amplifier is an exceptional sounding one. One the best I have heard at any price point.

Surprisingly when i remove the cover. I found out that the amp uses TL072 opamps which are quite outdated.
I am still confused why this amp sound superior to anything I have heard before.
TL072s, when used properly, are fine. While quite limited by modern standards, you can make them work well enough at line level for other factors (e.g. power amp output stage crossover distortion) to become the limiting factor. You will need decently high supplies for them though, e.g. +/- 12-15 V. +5 V single-supply will not be an option.
 
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See my first post was way late. OP had already showed that. Really nice and informative measurements
I see this post is about DIP opamps but for a reference for what is achiveable today a https://e1dashz.wixsite.com/index/cosmos-apu LPF is a nice reference. Not to expensive.
It has a LPF off course, but also a bal to unbal composit opamps. 170aol
That amp has really low feedback resistors as it can drive 100mA
One side 510 ohm resistors. The other 270 ohm
Measures really, really good with a source that can drive it. (Typically modern headphone amp)
I have one myself and the dipswitches gives hours of measuring fun. And maybe a little frustration and brainoverload
 
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Regarding feedback and source resistance I think the noise curves are illustrating. Aggregated noise values at frequency
This is unbalancing and balancing with opamps and resistors. Resistors go from 200ohm in steps of 200 ohms up to 4k. So a random common cirquit in audio.

cheap modern TI amp OPA167x
167x.jpg

Versus the same resistors and OPA1612
1612.jpg

On the cheap opamp you do not get noise down by going low resistance.
But as resistance rise you dont get mutch back for added cost of OPA1612
 
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