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

[Tommy-Geenexus]

The Moondrop Dawn Pro 2 has just been launched/announced, with dual CS43198 instead of the dual CS43131 of the Dawn Pro 1. No mention of which op-amps it's using. Other than slightly higher output power, the listed measurements are the same.

Would be interesting to see if they fixed the DRE distortion issue in the DP2, and if they'll ever do so for the DP1.

Btw @jkim the Google Doc list of Cirrus hump devices needs to be updated, what with the recent firmware fixes to some of the dongles.

They most likely have not. Moondrop is behind in terms of software, even compared to other chinese OEMs

 

[jkim]

Btw @jkim the Google Doc list of Cirrus hump devices needs to be updated, what with the recent firmware fixes to some of the dongles.

Thanks for the suggestion. Updated.

 

[Rantapossu]

I did some additional measurements with the Audient iD24. Since the headphone output volume control is digital, you can get rid of the Cirrus hump by appropriately limiting the output level (By turning the iD24's headphone output volume knob only up to a certain position.)

Of course this means that the headphone volume is no longer enough for all needs, but my Audio-Technica ATH-M40x -headphones sounded surprisingly loud and were perfectly adequate for the casual listening.

The limit seems to be 102.2 mV to 102.6 mV of output on my multimeter, depending on whether I measure the level using the 50 Hz 0 dBFS or 1000 Hz 0 dBFS sine wave. Anything above this level causes the Cirrus hump. The output jumps in 0.5 dB steps when the headphone volume knob is turned and the headphones produces a slight thump or click with each level change when adjusting the volume while the signal is playing.

These sweeps are taken with a 32-tone multitone signal...

First 102.2 mV. It is clean:

Then 129 mV. The Cirrus hump is starting to appear:

And finally 520 mV. At the levels of a typical cheap headphone dongle, the hump is already clearly visible:

Hopefully this will give some peace of mind to the Audient iD24 users...

 

[Rantapossu]

Of course, the entire Cirrus Hump can be eliminated by utilizing the Audient iD24's optical output and using an external DAC.

Here, for comparison, is the same sweep measured when the Audient iD24 feeds a Topping E50 DAC via Toslink:

 

[Luciferium]

The new firmware V1.70 for KA5 is now available!-FIIO---BORN FOR MUSIC

www.fiio.com

 

[Kaisertastiera]

I'm very sorry, friends. It seems that Topping has no plans to update the firmware for d30pro. I asked in their official Chinese group and got a reply from the boss……

 

[Kaisertastiera]

So sad
Topping's attitude is disappointing

 

[MBO]

It is necessary to write more critical and serious emails to Topping so that they do not think that customers will put up with anything.

 

[Kaisertastiera]

It is necessary to write more critical and serious emails to Topping so that they do not think that customers will put up with anything.

I just wrote one yesterday, and maybe you can write one too. Chinese companies always pay more attention to the voices of foreign markets...

 

[Ahmonge]

Email sent to Topping.

 

[Mike123]

There are usually two processors inside the DAC: an external one, which handles USB exchange, and an internal one, which sets the operating modes of the chips and works with the buttons and indicator. When I wanted to update the software on the internal controller on the Topping DX3Pro DAC, Topping told me that there is no way to update the software on the internal chip from the external interface. May be that the D30 Pro has the same situation. And sending the DAC to China en masse to disassemble it and update the firmware may be (or seem) too expensive for Topping.

 

[CedarX]

There are usually two processors inside the DAC

Interesting… I was under the impression that having one controller—the XMOS, Comtrue, Savitech, etc.—handling “everything” was more common…

Topping told me that there is no way to update the software on the internal chip from the external interface.

This would mean that Topping assigned the DAC configuration task to the UI (display, buttons..) controller, and not the USB bridge controller.
At the same time, there must be an internal programming port for that UI controller. It may not be accessible from the external (USB) interface as they said, but it shouldn’t be too difficult to reflash with the right programming module (usually a few Dollars…) after opening the D30pro.

 

[Mike123]

At the same time, there must be an internal programming port for that UI controller. It may not be accessible from the external (USB) interface as they said, but it shouldn’t be too difficult to reflash with the right programming module (usually a few Dollars…) after opening the D30pro.

Yes, of course. That's true. But it requires sending the DAC to the manufacturer. I wasn't so unhappy with a small problem that I could do that. I can even do it myself, I have the necessary equipment. But Topping didn't consider it possible to send me the firmware for the programmer.

Interesting… I was under the impression that having one controller—the XMOS, Comtrue, Savitech, etc.—handling “everything” was more common…

I'll tell you more. Until recently, manufacturers used old 8-bit chips because they have built-in EEPROM and it's easy to save parameters. Implementing parameter saving in ARM chips that don't have EEPROM seemed too troublesome to the manufacturer .

 

[ShinMolina]

The Fiio M21 is also getting the DRE setting blundled with the latest update.

https://www.fiio.com/newsinfo/1079836.html

 

[SoySalsaPicante]

The Fiio M21 is also getting the DRE setting blundled with the latest update.

https://www.fiio.com/newsinfo/1079836.html

Excellent! I was waiting for this. Can I assume this is (the same as) my JM21 DAP?

 

[jimmy_WAI]

Interesting… I was under the impression that having one controller—the XMOS, Comtrue, Savitech, etc.—handling “everything” was more common…

Out of topic: I know that XMOS, Comtrue, Savitech usb bridge has dedicated ASIO driver for Win10, how about SPV5048-Pro, CB5100-Pro, and Airoha AB1565 usb bridge?

Anyone could help me on this?

 

[creepy crow]

Tanchjim has also rolled out their DRE firmware update. Just update both the firmware and the app, and you'll find the DRE toggle in the app. The catch is, it's not on the official English site yet—you can only grab it from the Chinese official site. Here's the link:https://tanchjim.com/services/

 

[JohnYang1997]

So sad
Topping's attitude is disappointingView attachment 472842

It's not a matter if we want to upgrade D30pro's firmware or not. D30pro and other old models in that era are not capable of upgrading MCU firmware in the first place. Only XMOS firmware was upgradable.

On top of that, D30pro was discontinued for about/over two years now. (Which was only in production in less than a year)

 

[SoySalsaPicante]

Excellent! I was waiting for this. Can I assume this is (the same as) my JM21 DAP?

Never mind…M21 and JM21 are not the same. Guess I have to keep waiting and hope FiiO is working on this for JM21.

 

[Kaisertastiera]

It's not a matter if we want to upgrade D30pro's firmware or not. D30pro and other old models in that era are not capable of upgrading MCU firmware in the first place. Only XMOS firmware was upgradable.

On top of that, D30pro was discontinued for about/over two years now. (Which was only in production in less than a year)

So that's how it is...
Glad to see you explained it to us!