SMSL D400 Pro Balanced DAC Review

[Roland68]

Hard to say as I purchased an open-box unit.

What did they fix in the latest firmware?

-Ed

Maybe you could open up your D400 Pro when you get it and take some pictures of the inside.
Unfortunately, there are no pictures of the circuit board yet.

If you need help opening it, I know some pitfalls with these cases.

 

[Deleted member 72219]

Maybe you could open up your D400 Pro when you get it and take some pictures of the inside.
Unfortunately, there are no pictures of the circuit board yet.

If you need help opening it, I know some pitfalls with these cases.

This reviewer opened the unit:

-Ed

 

[Deleted member 72219]

Alright, the unit came in, and I have hooked it up.

I attempted to use the DSD Bypass mode and that was terrible. Literally distorted sounding on high frequencies (playing PCM signal). I switched to variable, set it to -0.0dB, then flipped it to fixed, and now it sounds great.

Never messing with that setting ever again!

And added bonus: perfect visual match for my PA200 bridged monobloc amps:

-Ed

 

[Scytales]

I am seeing this in the manual:
View attachment 433248

Does anyone know if the Fixed DSD Bypass setting is lower output voltage/volume than Fixed setting (1.85V RCA/3.7V XLR)? Or is it higher voltage/volume (3.7V RCA/7.4V XLR)? They don't state if the 3.7VRMS figure is RCA or if it's XLR. Or is it something else entirely and output voltage is still 2.5/5 RCA/XLR?

-Ed

I attempted to use the DSD Bypass mode and that was terrible. Literally distorted sounding on high frequencies (playing PCM signal). I switched to variable, set it to -0.0dB, then flipped it to fixed, and now it sounds great.

I concur that at SMLS, they have not done a great job when they have written the specifications of this D400PRO DAC.

I understand you drive your two PA200 each through their respective 'mono" input on XLR ? I very much suspect this input is not followed by a differential receiver, but that the signal at each pin of the XLR is directed towards the respective unbalanced input stage of each power amplifier (the left and the right channels) inside the PA200. A rudimentary phase inverting strategy to achieve bridge mono mode operation.

in any case, as the sensitivity of the mono input of the PA200 is specified at 2.1 V RMS, we now have a clue that the rated 3.7 V RMS fixed output voltage of the D400PRO DAC in DSD Bypass mode most probably apply to the balanced XLR outputs, since you just experienced the hard way a probable saturation of the input stages or your power amplifiers.

 

[Deleted member 72219]

I concur that at SMLS, they have not done a great job when they have written the specifications of this D400PRO DAC.

I understand you drive your two PA200 each through their respective 'mono" input on XLR ? I very much suspect this input is not followed by a differential receiver, but that the signal at each pin of the XLR is directed towards the respective unbalanced input stage of each power amplifier (the left and the right channels) inside the PA200. A rudimentary phase inverting strategy to achieve bridge mono mode operation.

in any case, as the mono input of the PA200 is specified at 2.1 V RMS, we now have a clue that the rated 3.7 V RMS fixed output voltage of the D400PRO DAC in DSD Bypass mode most probably apply to the balanced XLR outputs, since you just experienced the hard way a probable saturation of the input stages or your power amplifiers.

This is a very fair guess!

-Ed

 

[Kiko1974]

Hard to say as I purchased an open-box unit.

What did they fix in the latest firmware?

-Ed

There are a couple of glitches/issues on the D400 PRO 'though I've only detected one: on the set Up menu there's an option regarding DSD playing via I²S that is supposed to invert audio channels in case this is necessary. This option doesn't work despite I told SMSL about this around 6 months ago. They sent me the same so called firmware update before It was postee on their website, but others and me have tried to do the update but no luck. This "firmware" is supposed to address this.

 

[Roland68]

This reviewer opened the unit:

View attachment 433467

-Ed

Thanks for the tip. Finally a look inside the D400 Pro.
Looks like the single AK4499EX chip variant of the D400EX, which makes the D400 Pro even more valuable.

Now all I need is a look inside the SMSL VMV A2 .

 

[Kiko1974]

Thanks for the tip. Finally a look inside the D400 Pro.
Looks like the single AK4499EX chip variant of the D400EX, which makes the D400 Pro even more valuable.

Now all I need is a look inside the SMSL VMV A2 .

And all I need is a way to be able to do the firmware update to V2.0 to sort out some issues with this DAC. But despite following the provided instructions, there's no way te get It.
Anybody did?

 

[wada]

And all I need is a way to be able to do the firmware update to V2.0 to sort out some issues with this DAC. But despite following the provided instructions, there's no way te get It.
Anybody did?

It is actually possible steps are as follows:
1. install usb driver for Allwinner FEL mode (as shown in SMSL instruction) using "Zadig" tool - it is not SMSL DAC driver, but the one dedicated for software installation - better instruction/explanation is here https://linux-sunxi.org/FEL/USBBoot in section "Mandatry USB driver" (please install newest version of "Zadig" tool linked on mentioned page)
1a. (optional) test if usb driver installation was successful by checking in Windows Device Manager - start D400PRO in FEL mode (press knob and turn-on power - pressing still knob for 5 seconds) and check if you see in Device Manager new device having VID 1F3A and PID EFE8 and assigned the driver you just installed
2. download newest sunxi-tools (also linked on mentioned page) - unzip files - copy sunxi-fel.exe insted of the version received from SMSL
3. start D400PRO in FEL mode (press knob and turn-on power - pressing still knob for 5 seconds), open command prompt, change directory to the one where you have sunxi-fel.exe and test if the tool properly "see" D400PRO using commans:
sunxi-fel -l
(it should list available devices - ideally just one)
sunxi-fel version
(should return something like "AWUSBFEX soc=00001663(F1C100s) 00000001 ver=0001 44 08 scratchpad=00007e00 00000000 00000000")
4. execute "load.bat" delivered by SMSL - it will work this time

The issue is that version of the sunxi-fel tool delivered by SMSL is not working properly on Windows 11.

WADA

 

[Kiko1974]

It is actually possible steps are as follows:
1. install usb driver for Allwinner FEL mode (as shown in SMSL instruction) using "Zadig" tool - it is not SMSL DAC driver, but the one dedicated for software installation - better instruction/explanation is here https://linux-sunxi.org/FEL/USBBoot in section "Mandatry USB driver" (please install newest version of "Zadig" tool linked on mentioned page)
1a. (optional) test if usb driver installation was successful by checking in Windows Device Manager - start D400PRO in FEL mode (press knob and turn-on power - pressing still knob for 5 seconds) and check if you see in Device Manager new device having VID 1F3A and PID EFE8 and assigned the driver you just installed
2. download newest sunxi-tools (also linked on mentioned page) - unzip files - copy sunxi-fel.exe insted of the version received from SMSL
3. start D400PRO in FEL mode (press knob and turn-on power - pressing still knob for 5 seconds), open command prompt, change directory to the one where you have sunxi-fel.exe and test if the tool properly "see" D400PRO using commans:
sunxi-fel -l
(it should list available devices - ideally just one)
sunxi-fel version
(should return something like "AWUSBFEX soc=00001663(F1C100s) 00000001 ver=0001 44 08 scratchpad=00007e00 00000000 00000000")
4. execute "load.bat" delivered by SMSL - it will work this time

The issue is that version of the sunxi-fel tool delivered by SMSL is not working properly on Windows 11.

WADA

Thanks for your reply.
I've read your messsge carefully. It may be because I'm extremely busy with job, and that I am under treatment with a presciption medicstion that has morphine, but I find the updating process very tricky and hard to do st the moment. And believe, I have updating many components, from the time the update came as a compressed ISO that had to be burned to a CD, to more recent times that the update comes a file that has has to be transfered to an USB Drive (USB stick, an SD card.
Why can't SMSL issues a plain and easy to do firmware update like they did with other of their components?
I've owned an SMSL D0300, I had to update its firmware, and I found the updating very easy to do.

 

[wada]

Thanks for your reply.
I've read your messsge carefully. It may be because I'm extremely busy with job, and that I am under treatment with a presciption medicstion that has morphine, but I find the updating process very tricky and hard to do st the moment. And believe, I have updating many components, from the time the update came as a compressed ISO that had to be burned to a CD, to more recent times that the update comes a file that has has to be transfered to an USB Drive (USB stick, an SD card.
Why can't SMSL issues a plain and easy to do firmware update like they did with other of their components?
I've owned an SMSL D0300, I had to update its firmware, and I found the updating very easy to do.

Hi Kiko1974,

I fully agree with you - user experience could be better - it is my first SMSL device, so unfortunately I have no other refference point to compare with - in case of other brands I was using it was typically easier . What SMSL proposed is rather approach used by developers working with embedded systems. Before purchase I was mentally prepared by your messages in this thread that upgrade is not steight forward, so having this perspective I was quite happy to solve the issue.

What would be usefull in SMSL instruction are requirements (on which OS it is working) and how to confirm each major step as successfull.

There are 3 major steps for upgrade:
- implement windows driver required for communication with Allwinner F1C100s processor during firmware upgrade
- implement (download and extract) current tool to upload firmware (sunxi-fel.exe)
- upload firmware files to D400PRO using commands provided by SMSL in load.bat

If you wish I will prepare more datailed instruction (elaborating about each step) during next days.

After last couple days I am extremally happy with sound quality of D400PRO - firmaware 2.0 seems to resolve problems found with 1.0 (and created new ones - you will see after upgrade) - I bought this DAC for hqplayer, so was testing mainly USB and bypass mode - it is just great, and my Cyan2 will have to share the space with D400PRO. I hope SMSL will still provide updates - will see.

WADA

 

[Kiko1974]

Hi Kiko1974,

I fully agree with you - user experience could be better - it is my first SMSL device, so unfortunately I have no other refference point to compare with - in case of other brands I was using it was typically easier . What SMSL proposed is rather approach used by developers working with embedded systems. Before purchase I was mentally prepared by your messages in this thread that upgrade is not steight forward, so having this perspective I was quite happy to solve the issue.

What would be usefull in SMSL instruction are requirements (on which OS it is working) and how to confirm each major step as successfull.

There are 3 major steps for upgrade:
- implement windows driver required for communication with Allwinner F1C100s processor during firmware upgrade
- implement (download and extract) current tool to upload firmware (sunxi-fel.exe)
- upload firmware files to D400PRO using commands provided by SMSL in load.bat

If you wish I will prepare more datailed instruction (elaborating about each step) during next days.

After last couple days I am extremally happy with sound quality of D400PRO - firmaware 2.0 seems to resolve problems found with 1.0 (and created new ones - you will see after upgrade) - I bought this DAC for hqplayer, so was testing mainly USB and bypass mode - it is just great, and my Cyan2 will have to share the space with D400PRO. I hope SMSL will still provide updates - will see.

WADA

I'm Happy you like the sound of the D400 PRO. I personally LOVE the sound of It, opposed to the then Sabre top of the like DO300. I think me being so Happy with the sound of the D400 PRO must be a Matter of sinergy with the rest of the components on my set Up (integrated amplifier, Marantz PM6007, speakers,, KEF Q550 and subwoofer, B&W ASW608, nothing fancy but I think I matched components quite well, and the SMSL D400 PRO is part of that sinergy).
Yes, please, I would appreciate if you could elaborate the updating just a little.
Thanks in advanced.

 

[MatteoS]

new version fw !

 

[Kiko1974]

View attachment 460650 new version fw !

I Hope it's not as hard to update as the previous version, which I still haven't been able to instal.
SMSL has a lousy customer support and their updated are a nightmare to instalo, and I've updated tons of devices.

 

[Blas M.]

I'm looking for help on getting the SMSL 400 Pro to work. The application is SACD from a DVD player via HDMI. My Sony DVD output from the audio HDMI is set to DSD. This is going to a Chinese Audio Extracter (HDMI/MHL Interface Audio I2S/DSD/Optical/Coaxial HDMI To I2S IIS for DOP Board) whose outputs are connected to the SMSL 400 Pro I2S and Coax inputs. The SMSL is displaying DSD for the IS2 and DOP for the Coax. But nothing is coming out from the RCA outputs (set to unbalanced). I just updated the firmware to V2.1 and that had no effect. Any suggestions?

 

[Kiko1974]

I'm looking for help on getting the SMSL 400 Pro to work. The application is SACD from a DVD player via HDMI. My Sony DVD output from the audio HDMI is set to DSD. This is going to a Chinese Audio Extracter (HDMI/MHL Interface Audio I2S/DSD/Optical/Coaxial HDMI To I2S IIS for DOP Board) whose outputs are connected to the SMSL 400 Pro I2S and Coax inputs. The SMSL is displaying DSD for the IS2 and DOP for the Coax. But nothing is coming out from the RCA outputs (set to unbalanced). I just updated the firmware to V2.1 and that had no effect. Any suggestions?

I don't have an answer to your question, It seems Strange, It shouldn't happen.
With the configuration you're describing is should work and get audio, either PCM or DSD from the D400 PRO. Try resetting It, keep It a minute or so unplugued from the mains and then then try again.
I must say, Lucky you. I haven't got to update my DO400 PRO either to firmware 2 or 2.1, and I'm tired of trying It, following the instructions verbatim.

 

[Kiko1974]

I'm looking for help on getting the SMSL 400 Pro to work. The application is SACD from a DVD player via HDMI. My Sony DVD output from the audio HDMI is set to DSD. This is going to a Chinese Audio Extracter (HDMI/MHL Interface Audio I2S/DSD/Optical/Coaxial HDMI To I2S IIS for DOP Board) whose outputs are connected to the SMSL 400 Pro I2S and Coax inputs. The SMSL is displaying DSD for the IS2 and DOP for the Coax. But nothing is coming out from the RCA outputs (set to unbalanced). I just updated the firmware to V2.1 and that had no effect. Any suggestions?

My player is a Sony UBP X-8OO M2, I'm using the same Chinese HDMI audio extractor as you an an SMSL DO400 PRO.
Sony BD/UHD BD players don't provide enough power to get the Chinese HDMI audio extractor to work, so you need an external power supply to make It work. 'Though by the Chinese HDMI audio extractor is supposed to work at 5 volt/1Amp, I suggest you to use use a power supply of 5 volts and at lest 2 Amps. If it's a linear power supply, It Will work better. You can get one like the one I'm using from AliExpress, that's a linear power supply, not a simple power transformer, for around 60/65 €. Believe, it's really worthwhile to spend a little more money on a linear power supply.

 

[Blas M.]

The firmware update may be wishful thinking on my part. I have not found a way to display the firmware version on the DAC. If someone could post the procedure to display the firmware version on this DAC, that would be helpful. SMSL has not documented it.

I did have issues with the download and installation of the firmware, but I was able to overcome them. After downloading, unzipping, and reading the instructions in the pdf, I had to pull some files out of their folders into the main folder in order to make the contents match the image in the pdf. The bat file that needs to be run does not match the name in the installation step in the pdf. I found that I had to rerun Zadir immediately before running the installation bat file. The prior time I ran the bat file after connecting the USB, it errored out with an error message similar to what I have seen posted. I am assuming since it finally ran without an error, the firmware was updated. Needless to say, this was not the most straight forward firmware process I've encountered.

I was running the extractor with a 5V wall wart power supply attached. I will look at adding a linear one as you suggested. I don't think it will fix the current issue but could help audio quality in the long term.

As stated earlier, the display of DSD and DOP on the DAC screen makes me think the extractor is working. However, if the output format has a error, that also could also be a cause for the lack of sound. It doesn't help that HDMI audio extractor comes with no documentation.

 

[Kiko1974]

The firmware update may be wishful thinking on my part. I have not found a way to display the firmware version on the DAC. If someone could post the procedure to display the firmware version on this DAC, that would be helpful. SMSL has not documented it.

I did have issues with the download and installation of the firmware, but I was able to overcome them. After downloading, unzipping, and reading the instructions in the pdf, I had to pull some files out of their folders into the main folder in order to make the contents match the image in the pdf. The bat file that needs to be run does not match the name in the installation step in the pdf. I found that I had to rerun Zadir immediately before running the installation bat file. The prior time I ran the bat file after connecting the USB, it errored out with an error message similar to what I have seen posted. I am assuming since it finally ran without an error, the firmware was updated. Needless to say, this was not the most straight forward firmware process I've encountered.

I was running the extractor with a 5V wall wart power supply attached. I will look at adding a linear one as you suggested. I don't think it will fix the current issue but could help audio quality in the long term.

As stated earlier, the display of DSD and DOP on the DAC screen makes me think the extractor is working. However, if the output format has a error, that also could also be a cause for the lack of sound. It doesn't help that HDMI audio extractor comes with no documentation.

Could you please explain what files on the uncompressed/inzip step you had to move and where.
I've tried both update v2.0 and 2.1 over twenty times following the provided instructions and have been unable to update my D400 PRO.

 

[Blas M.]

I moved the files (First Installation and zadig-2.7) from the USB DRV TOOL folder up a level after the initial unzipping.
I ran Zadig 3 times. The first time was the initial install per the directions. The second time to update it to zadig-2.9 and the third time immediately before the install which made sure the software was active in the computer memory. Otherwise I just followed the instructions.