On the Distortion of Cirrus Logic CS431xx-Based Devices: A Comparative Review

[jkim]

What do you think? Maybe it's time to contact Cirrus officially? Maybe Amir will write a serious letter? This could greatly help Cirrus to take these errors into account. Maybe they will make recommendations to manufacturers to avoid the problem?

Already contacted by some (not Amir, though). I heard from some industry insider that it is difficult even for audio gear manufacturers to get direct access to engineers at semiconductor companies...

Excellent work, congratulations.
I have TANCHJIM Space and through the app I selected non-oversampling (NOS). In UAPP, settings, USB Audio, authorize "increase to highest rate," rate relative to the DAC's capabilities (TANCHJIM Space 384khz)
Will this do the job?

I don't know how UAPP handles this case. When I get a chance, I will measure it as I have an Android phone.

Has anyone done an ABX with the "good" units, such as the JM20?

As I mentioned in the review, it is non-trivial to resolve the distortion's audibility issue by conducting ABX listening tests using arbitrary material. The test clips provide clear cases, as described here.

 

[Rotiv]

The settings I selected on UAPP only show 348 kHz sampling after restarting the Pixel 8.

 

[TechLvr2]

currently i could only give the android app right now. since the windows version is a python script and sorta kinda made windows defender unhappy and deleted it.(idk why, maybe it doesnt like seeing code that interacts with usb devices). ill try to recover or remake it.

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maybe ill just post them in github if i ever stopped procrastinating
edit: heres the source code for the android app: https://github.com/cheesyserg/blackPearlControl-Android

@KDRN
Thank you for your efforts. I know, no good deed goes unpunished but would you mind reposting the link to your Android app please? The link does not appear to be working. I have a Black Pearl on the way and your app looks like a great solution for the settings. Happy to buy it if you want to publish it in the app store etc.
Thanks again

 

[pangcukaipang]

I also have TempoTec Variations V1 DAP, which also uses Dual CS43131, on the way. I'm curious about its performance regarding this Cirrus Hump issue.

My TempoTec Variations V1 DAP has arrived. Sadly, there are no NOS on digital filter, only Fast LL, Fast PC, Slow LL, and Slow PC.

 

[Kaisertastiera]

Can someone send a d30pro for testing? Thank you. My dac is this, which is very important to me.

My native language is not English, this passage is translated by Google.

 

[jkim]

Can someone send a d30pro for testing? Thank you. My dac is this, which is very important to me.

My native language is not English, this passage is translated by Google.

It is unlikely anyone will send me a Topping D30 Pro for testing. If you're concerned about Cirrus hump distortion, you can check if your D30 Pro produces it in a listening test.

• Download the C Major test signal from here.
• Set your D30 Pro's volume to -15 dB.
• Set your USB host device's (and your player software's) volume to max.
• Start listening to the signal with your headphone/speaker amp's volume set to a comfortable level. Check if you hear some 'clicking' noise along with low-frequency sound in the test signal. You may increase the amp's volume a bit more to hear more clearly.

 

[Kaisertastiera]

不太可能有人会送我一台 Topping D30 Pro 来测试。如果你担心卷云驼峰失真，可以试试你的 D30 Pro 的听音测试。

• 从这里下载 C 大调测试信号。
• 将 D30 Pro 的音量设置为-15 dB。
• 将 USB 主机设备（和播放器软件）的音量设置为最大。
• 将耳机/扬声器放大器的音量调到合适的水平，开始聆听信号。检查测试信号中是否有“咔哒”声以及低频噪音。您可以稍微调高放大器的音量，以便听得更清楚。

Got it, thank you!

 

[Kaisertastiera]

I downloaded the audio provided by jkmi and used the combination of a30pro+d30pro+dt900prox to listen to the audio. I'm sorry to tell you that Topping's cs still has this problem. Using a filter other than f5 will cause distorted noise at the beginning, and f5nos filtering can indeed solve this problem.

 

[jkim]

I downloaded the audio provided by jkmi and used the combination of a30pro+d30pro+dt900prox to listen to the audio. I'm sorry to tell you that Topping's cs still has this problem. Using a filter other than f5 will cause distorted noise at the beginning, and f5nos filtering can indeed solve this problem.

That's what I expected. No manufacturer has been aware of this distortion issue when they designed their products.

Just use the NOS mode and make sure audio is upsampled to 192 k or 384 kHz by your operating system. I confirmed Windows' upsampling works properly. Will check other operating systems when I get a chance.

 

[Kaisertastiera]

That's what I expected. No manufacturer has been aware of this distortion issue when they designed their products.

Just use the NOS mode and make sure audio is upsampled to 192 k or 384 kHz by your operating system. I confirmed Windows' upsampling works properly. Will check other operating systems when I get a chance.

Thank you, I use mac os 13.

 

[jkim]

Thank you, I use mac os 13.

By the way, which distortion pattern do you hear from your D30 Pro playing the C Major clip?

This?

Or this?

 

[Kaisertastiera]

By the way, which distortion pattern do you hear from your D30 Pro playing the C Major clip?

This?
View attachment 463186

Or this?
View attachment 463187

I'm sorry, I didn't know. I can't read the spectrum. I'm a classical music student. I don't know much about audio science and technology.
The distortion I hear is that there is extra noise at the beginning, while the nos filter does not.

 

[jkim]

I'm sorry, I didn't know. I can't read the spectrum. I'm a classical music student. I don't know much about audio science and technology.
The distortion I hear is that there is extra noise at the beginning, while the nos filter does not.

You should be able to hear three cycles of pulsating low-frequency tones whether there's distortion or not. The distortion, if any, is not just at the beginning of the test clip. It should be only one of the three cases:

1. No distortion: We hear only the low-frequency tones.
2. Partial distortion: We hear 2 to 3 clicks at the beginning of each of the three low-frequency tone cycles.
3. Full distortion: We hear many clicks throughout the test clip along with the low-frequency tones.

 

[Kaisertastiera]

You should be able to hear three cycles of pulsating low-frequency tones whether there's distortion or not. The distortion is not only at the beginning of the test clip. It should be only one of the three cases:

1. No distortion: We hear only the low-frequency tones.
2. Partial distortion: We hear 2 to 3 clicks at the beginning of each of the three low-frequency tone cycles.
3. Full distortion: You hear many clicks throughout the signal along with the low-frequency tones.

When using other filters I hear the second one, when using filter nos5 I hear the first one.

 

[Kaisertastiera]

The distortion noise I heard was indeed three clicks.
When I was listening to the soundtrack of Monster Hunter, I heard similar noises in some electronic music parts. I used to think it was a problem with dt900prox, but now I understand that it was a problem with the CS part.

You should be able to hear three cycles of pulsating low-frequency tones whether there's distortion or not. The distortion, if any, is not just at the beginning of the test clip. It should be only one of the three cases:

1. No distortion: We hear only the low-frequency tones.
2. Partial distortion: We hear 2 to 3 clicks at the beginning of each of the three low-frequency tone cycles.
3. Full distortion: We hear many clicks throughout the signal along with the low-frequency tones.

 

[Kaisertastiera]

You should be able to hear three cycles of pulsating low-frequency tones whether there's distortion or not. The distortion, if any, is not just at the beginning of the test clip. It should be only one of the three cases:

1. No distortion: We hear only the low-frequency tones.
2. Partial distortion: We hear 2 to 3 clicks at the beginning of each of the three low-frequency tone cycles.
3. Full distortion: We hear many clicks throughout the test clip along with the low-frequency tones.

The humiliating thing is that I have sold many headphones because of this noise in the Monster Hunter soundtrack. I used to think that it was because my headphones were not high-end equipment and "lacked resolution", haha.

 

[ducnsh]

It is unlikely anyone will send me a Topping D30 Pro for testing. If you're concerned about Cirrus hump distortion, you can check if your D30 Pro produces it in a listening test.

• Download the C Major test signal from here.
• Set your D30 Pro's volume to -15 dB.
• Set your USB host device's (and your player software's) volume to max.
• Start listening to the signal with your headphone/speaker amp's volume set to a comfortable level. Check if you hear some 'clicking' noise along with low-frequency sound in the test signal. You may increase the amp's volume a bit more to hear more clearly.

Just try the procedure except the "-15dB step" since I do not know how to set it, on iBasso DC07 Pro (4xCS43131), with Fast filter, I do not hear any clicking noise along with the low-frequency sound.

 

[Ahmonge]

I ran the test with my combo D30 Pro + A30 Pro, at 0dB (DAC mode) and got two clicks on the second and third bass waves. I'll do it again in PRE mode with -15 dB volume set.

 

[VyseLegendaire]

Some thoughts after some time thinking and experimenting with this;

A. its a mistake I think to assume DAC/AMP makers did not know about the CS distortion issue. I don't have sources but its a known phenomenon I have read about in places for years. Likely they just believed it would go ignored or considered it too minute compared to other chip characteristics considerations (basically, there is a near universal concensus that the CS43131 is 'the chip' for marketing purposes)

And its nearly 100% for sure that the behavior of some CS devices minimizing the click sounds to the beginning of the audio clip is also an engineering goal and not a coincidence.

B. Why does it matter to engineer this away if we can just lock the device to or manually choose NOS filter?

Noise floor and Dynamic Range are audible characteristics in music, and it shows. Nearly all the audio A-B tests I've done give me better listening results with the standard filters compared to NOS, taking into account the potential background distortion.

In other words, the activation of the DRE feature actively improves signal clarity/ reduces background noise, and boosts dynamism in any given music sample. An example would be a high-res piano solo music where with NOS, audible recording background noise is audible increased (with 364k upsampling active), or any given rock song featuring clearly strum guitar chords - they will lack initial attack and articulation and/or total power in comparison to standard shape filters. These examples seem to apply nearly universally with slightly different interpretations for any type of music. Basically, noise goes down and music signal sounds stronger with DRE active.

but I just had to get this out there. If you think you're improving your listening experience by cancelling DRE to avoid click distortion, be aware there is a concomitant, marked degradation in audible sound quality.

I have the Fosi DS2 on the way this week and I'll compared what the results are of that compared to the Black Pear with both NOS and shape filters applied. We'll see where or how much distortion/clicks it exhibits, and whether its sound quality implies always-active DRE, or always-off DRE.

Note: I am always and in all cases using Unbalanced audio 3.5 mm cables only.

 

[roladyzator]

The workaround works on the KA15 as well, tested with the firmware 1.0.4.
384 kHz is the maximum sample rate at which the onboard EQ still works.