Hires 96/24 listening test of opamps

Which of the files do you prefer by listening?

  • rr = LM4562

    Votes: 1 4.5%
  • ss= OPA2134

    Votes: 2 9.1%
  • tt = MA1458

    Votes: 2 9.1%
  • uu = TL072

    Votes: 9 40.9%
  • vv = OPA2134

    Votes: 1 4.5%
  • I can not hear a difference

    Votes: 7 31.8%

  • Total voters
  • Poll closed .
As a follow-up to the thread
I am posting a new opamp test, this time in 96kHz/24bit resolution. The music samples may be downloaded from
The file is quite big, about 160MB, as a result of higher resolution format.

The samples have a lot of information above the audio band, as you can see from the attached spectrogram. It is a true hires, not the file create by ultrasonic noise addition, as is sometimes quite usual.

The link level was now 2Vrms = 0dBFS.

The poll is valid for 10 days. Please do not write your comments to the forum, but rather send it to me to my PM here or to my e-mail address.

It would be nice if you could support your preferences by an ABX result, should be signed like in this example:
This allows verification of validity of your result.

Thank you and have fun!

Poll question "I can not hear a difference" was added on June 25. Please feel free to vote for this option in case that all the files sound same to you, without audible difference.
June 27
The poll has been closed and it's time to reveal the parts used:

rr – LM4562 (1 vote)
ss – OPA2134 first take (2 votes)
tt – MA1458 (2 votes)
uu – TL072 (9 votes – big winner :))
vv – OPA2134 second take (1 vote)

So, according to the poll, the winner is TL072 :D. I have also received preferences via PM and I tried to create a chart from them.

This shows a different view, very contradictory and there are not many mutual preferences among the voters.

Moreover, none of the votes was supported by a valid ABX result, so I would leave to a reader to make his conclusion himself. However, there is one very interesting result, “Voter 2” preferred the parts just according their parameters with one exception, two takes of OPA2134. Great job, Mark! :)

I have prepared some more information, together with measurements, and placed it to my web:

Op amps listening test with hires files

Thanks to everyone who participated in this test.

As a bonus, I am adding the original source file which was used in the test:


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On a technical note: the worst opamp in this test has now THD at 10kHz = 0.064% and is about 20x worse in distortion at 10kHz than the digital chain. This is the result of higher voltage level in this test. Also, the differences in signals are higher than in the previous test. The best opamps again make a direct copy of the digital chain properties.
Well, I hope you guys will be much better than me in the ABX ;)

foo_abx 2.0.2 report
foobar2000 v1.3.7
2017-06-18 09:52:50

File A: rr.wav
SHA1: e374d11099f329141cf3cf553f646f49102aaaba
File B: tt.wav
SHA1: 1a956970e62c3aaeea483c29334833c82a612e84

WASAPI (push) : SPDIF-Out (USB Sound Blaster HD), 24-bit
Crossfading: NO

09:52:50 : Test started.
09:54:37 : 01/01
09:54:48 : 02/02
09:55:08 : 02/03
09:55:20 : 02/04
09:55:36 : 03/05
09:55:47 : 03/06
09:55:58 : 04/07
09:56:14 : 05/08
09:56:14 : Test finished.

Total: 5/8
Probability that you were guessing: 36.3%

 -- signature -- 
Pavel, as I told you by mail, now it has taken me more to differentiate between them. I suppose it is due to the 2 Vrms and the greater separation from the noise.

And it cost me less work with the AV Marantz SR4500 (KEF Q100 speakers and the Takstar ts671 headphones, cheap but with very good sound after tweaked + recabling) than with the ifi iCAN even though the headphone amplifier has a SNR of 117 dB. Perhaps the iCAN's switched power supply is the bottleneck.


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Paid Member
2007-09-15 8:14 am
Not doing very well here. The one I don't like seems to vary. The intro is good, vocals less so. I'm going to stick with that as the 1458 at the moment.

I've blanked out the tracks to keep the files that I'm choosing anonymous.

Maybe I should stock up on 741's and 1458's. After all, if you can't tell the difference then using the lowest cost device to achieve the desired result is called 'engineering' ;)

Who said that :eek:


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Mooly, What I do to find a good spot to listen to is load all the files in Reaper, then un-mute one at a time, and go up and down though the tracks trying to notice when things sound a little different.

For example, right now I am listening to an interesting cymbal hit that is looping from 0:07.50 to 0:08.15. A little more than 1/2 second in the loop.

That particular hit has a little HF ring in it that I think may sound a little more or less grainy on some of the tracks. Wish I could still hear above 10 kHz, as I would expect most of the difference to be up there for this kind of test.

By the way, trying to continuously loop 1/2 second in Foobar while listening carefully is almost impossible for me. Maybe I'll ask someone to be the computer operator so I can give all my attention to listening.
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