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Can you hear crossover distortion of >1% (listening test)

Can you hear a difference between the files in the ABX test

  • I can hear a difference and I have an ABX result

    Votes: 2 40.0%
  • I cannot hear a difference

    Votes: 3 60.0%

  • Total voters
    5
  • Poll closed .

pma

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I have prepared another test, this time on audibility of poor class AB crossover distortion. Original sound file was sent through the class AB circuit (DIY-like of 1960's) in MicroCap MC11 simulator. The resulting distorted wav file was used as a second test file.

This is the amplifier circuit
Lowend amp.png


THD+N vs. output power at 1kHz, from 10mW up to clipping, looks like this
Lowend amp distortion.png


and this is the spectrum at moderate output level
Lowend amp spectrum.png


So we can see that the amp has full spread of harmonics even at lower output level. Yes it is not as bad as if it had zero bias, but such amps have rarely existed.

The test file amplitude level reaches to about 70% of amplifier clipping level.

The test files are at

If you are interested in a test, please download the files, make an ABX test (best in foobar plug-in) and post the test report. Thank you!

Feel free to use #Deltawave software to analyze the files.

Have a good listening!
 

xpop

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No way many amplifier with so much distortion existed ! Perhaps the first tube amplifiers ?
 
OP
pma

pma

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The positive result in the poll which is not supported by the ABX log signature is invalid.



The log signature looks like this:

foo_abx 2.0.2 report foobar2000 v1.4.8 2022-03-06 21:50:25 File A: lowend_1.wav SHA1: 92490329fcb02d42c40458cf5bb4fcc3ba60f008 File B: lowend_a.wav SHA1: 69d26d1556ac8f5bfd140321e1b047bd5af4a487 Output: ASIO : Focusrite USB ASIO Crossfading: NO 21:50:25 : Test started. 21:50:51 : 01/01 21:50:56 : 02/02 21:51:00 : 03/03 21:51:04 : 03/04 21:51:17 : 03/05 21:51:22 : 04/06 21:51:26 : 04/07 21:51:30 : 05/08 21:51:35 : 06/09 21:51:39 : 06/10 21:51:44 : 07/11 21:51:50 : 08/12 21:51:59 : 08/13 21:52:05 : 08/14 21:52:11 : 08/15 21:52:16 : 09/16 21:52:16 : Test finished. ---------- Total: 9/16 Probability that you were guessing: 40.2% -- signature -- a1126c9aad7b87b7f23b4c210df25a00334c67bb

Trial count must be at least 10 trials, better 16. The P number is to be P <= 0.05 to make a statistically significant result. Cherry picking is not possible.
 
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pma

pma

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No way many amplifier with so much distortion existed ! Perhaps the first tube amplifiers ?

There were amplifiers and there still are amplifiers with similar level of distortion, even here measured by @amirm


The question is audibility and this can be proven only by a valid DBT test.
 

abdo123

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There were amplifiers and there still are amplifiers with similar level of distortion, even here measured by @amirm


The question is audibility and this can be proven only by a valid DBT test.

That amplifier is a DIY toy though, hardly a real amplifier.
 

TheBatsEar

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Tom C

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Crossover distortion is not the same thing as harmonic distortion. Amp camp amp is class A, so crossover distortion is exactly zero.
 
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pma

pma

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I am not interested in debates of what is an amplifier or not, or what is a distortion of some kind or not. The only goal is to investigate audibility and the only proof is a valid result of the ABX test, to me. So far, not a single one was posted.
 

fictive

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foo_abx 2.0.6d report foobar2000 v1.6.10 2022-03-06 14:22:59 File A: lowend_1.wav SHA1: 92490329fcb02d42c40458cf5bb4fcc3ba60f008 File B: lowend_a.wav SHA1: 69d26d1556ac8f5bfd140321e1b047bd5af4a487 Output: Default : Primary Sound Driver Crossfading: NO 14:22:59 : Test started. 14:23:23 : 01/01 14:23:32 : 02/02 14:23:38 : 03/03 14:23:41 : 04/04 14:23:44 : 05/05 14:23:48 : 06/06 14:23:51 : 07/07 14:23:55 : 08/08 14:23:58 : 09/09 14:24:02 : 10/10 14:24:05 : 11/11 14:24:09 : 12/12 14:24:12 : 13/13 14:24:15 : 14/14 14:24:18 : 15/15 14:24:54 : 16/16 14:24:54 : Test finished. ---------- Total: 16/16 p-value: 0 (0%) -- signature -- 61b39329f96b4610a4b4dd8410e3d71d5f7a222e

My ABX result. The difference is very audible to me and the distorted file sounds to be lowend_1. There's a crunchiness present in that one that isn't present in lowend_a.
 
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pma

pma

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foo_abx 2.0.6d report foobar2000 v1.6.10 2022-03-06 14:22:59 File A: lowend_1.wav SHA1: 92490329fcb02d42c40458cf5bb4fcc3ba60f008 File B: lowend_a.wav SHA1: 69d26d1556ac8f5bfd140321e1b047bd5af4a487 Output: Default : Primary Sound Driver Crossfading: NO 14:22:59 : Test started. 14:23:23 : 01/01 14:23:32 : 02/02 14:23:38 : 03/03 14:23:41 : 04/04 14:23:44 : 05/05 14:23:48 : 06/06 14:23:51 : 07/07 14:23:55 : 08/08 14:23:58 : 09/09 14:24:02 : 10/10 14:24:05 : 11/11 14:24:09 : 12/12 14:24:12 : 13/13 14:24:15 : 14/14 14:24:18 : 15/15 14:24:54 : 16/16 14:24:54 : Test finished. ---------- Total: 16/16 p-value: 0 (0%) -- signature -- 61b39329f96b4610a4b4dd8410e3d71d5f7a222e

My ABX result. The difference is very audible to me and the distorted file sounds to be lowend_1. There's a crunchiness present in that one that isn't present in lowend_a.

Thank you! You are right.

foo_abx 2.0.2 report foobar2000 v1.4.8 2022-03-07 10:14:31 File A: lowend_1.wav SHA1: 92490329fcb02d42c40458cf5bb4fcc3ba60f008 File B: lowend_a.wav SHA1: 69d26d1556ac8f5bfd140321e1b047bd5af4a487 Output: ASIO : Topping USB Audio Device Crossfading: NO 10:14:31 : Test started. 10:16:01 : 01/01 10:16:11 : 02/02 10:16:25 : 03/03 10:16:37 : 04/04 10:16:56 : 05/05 10:17:12 : 06/06 10:17:23 : 07/07 10:17:34 : 08/08 10:17:44 : 09/09 10:18:00 : 10/10 10:18:19 : 11/11 10:18:31 : 12/12 10:18:51 : 13/13 10:19:09 : 14/14 10:19:57 : 15/15 10:20:08 : 16/16 10:20:08 : Test finished. ---------- Total: 16/16 Probability that you were guessing: 0.0% -- signature -- fae72038449e56cb47a5eff314d854d13c84e5fc
 
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