SMSL filters mislabeled on ES9039 DACs

[Lombrigas]

Could you post this in English?

Hello, I have been reading this topic for several days and it is extremely interesting. I have recently acquired a DO100Pro and unfortunately I am having trouble understanding everything about the bad labeling of the filters. I use it in XLR on a Nuprime Sta9 and as a source a Wiim Pro Plus in Coaxial with Qobuz. From what I understand, the best filter is the FL2 or FL4 position ? Can you confirm that I have understood the subject correctly? In addition, when the DO100Pro is turned on and without a conference, it creates a "POP" in the speakers. I have tried several cables and nothing changes. Thank you very much for your topic.

 

[JIW]

Hello, I have been reading this topic for several days and it is extremely interesting. I have recently acquired a DO100Pro and unfortunately I am having trouble understanding everything about the bad labeling of the filters. I use it in XLR on a Nuprime Sta9 and as a source a Wiim Pro Plus in Coaxial with Qobuz. From what I understand, the best filter is the FL2 or FL4 position. Can you confirm that I have understood the subject correctly? In addition, when the DO100Pro is turned on and without a conference, it creates a "POP" in the speakers. I have tried several cables and nothing changes. Thank you very much for your topic.

What each filter is depends on the firmware and type of chip. For the original FW with Q2M chips, FL4 would be my choice with FL3 and FL4 worthy of consideration. I don't recall the DO100Pro receiving a FW update and I cannot be bothered to reread the thread to see since I got myself a Topping DX5 II in June to no longer have to deal with SMSL's software issues.

 

[Lalosama]

Hi. I'm new in ASR. I buy this week the SMSL DL200, Great sound. Searching more info about the filters I found this thread. I want to know which filter is better for prominent low frequencies and more relaxed high frequencies?

I try to update the firmware to fix the filters labels, but it was impossible. When I open the MCU 1.3 app don't detect the SMSL DL200 in any way, trying all methods but not success.

 

[Roland68]

Hi. I'm new in ASR. I buy this week the SMSL DL200, Great sound. Searching more info about the filters I found this thread. I want to know which filter is better for prominent low frequencies and more relaxed high frequencies?

I try to update the firmware to fix the filters labels, but it was impossible. When I open the MCU 1.3 app don't detect the SMSL DL200 in any way, trying all methods but not success.

Did you make sure that the USB and power cables are not plugged in and then plugged in in the correct order?

 

[Lalosama]

Did you make sure that the USB and power cables are not plugged in and then plugged in in the correct order?

Yes, I tried in both ways: first plugging the USB and then the power, and reverse. In the list of COM ports I didn't see any new device. I try restarting the notebook, reinstalling xmos drivers, nothing.

When I connect the USB without power, I see in device manager "USB Serial" with a exclamation mark. I'm not sure what I'm doing wrong.

EDIT: I still want to know which filter is the best for prominent low frequencys and more relaxed high frequencys. Using the default labels of the filters.

 

[xanalog]

Did you make sure that the USB and power cables are not plugged in and then plugged in in the correct order?

What a dumbsh*t nuisance process.
Clicking heels thrice should be part of the procedure.
And the user must to do this each time upon power up of the source and/or this device.

 

[Roland68]

What a dumbsh*t nuisance process.
Clicking heels thrice should be part of the procedure.
And the user must to do this each time upon power up of the source and/or this device.

Only during firmware updates, but yes, it could be simpler.
Unfortunately, SMSL has many shortcomings in this area; that's undeniable.

 

[BachAudioDK]

Hi Was a bit confused about the Filters on my DO100 Pro, so I decides to measure the Filter Impulse responses of FL1 to FL7 settings:

My SMSL DO100 Pro with Firmware SMSL DO100PRO_MCU_V1.1_240925

Maybe some one can decode what they correspond to in the ESS datasheet for ES9039Q2M. The Linear Phase are not so easy to decode from my not so good images.

Im pretty confident about FL1, FL5, FL7

FL6 can either be Minimum Phase or Minimum Phase Fast Roll-Off

FL2, FL3, FL4 are Linear Phase, but not easy to visual decode from impulse response on scope.

Cheers
Flemming Bach
Denmark

FL1 (Minimum Phase Slow Roll-Off Low Dispersion)

FL2:

FL3:

FL4:

FL5: (Linear Phase Slow Roll-Off)

FL6:

FL7: (Minimum Phase Slow Roll-Off)

 

[xanalog]

...I don't recall the DO100Pro receiving a FW update and I cannot be bothered to reread the thread to see since I got myself a Topping DX5 II in June to no longer have to deal with SMSL's software issues.

If only, I knew!
I have three SMSLs:
*One has USB and network issues.
*Another has ARC issues.
*The AO200MkII (for desktop) has been bug free. Though, I always knock-on-wood before switching to its USB input.

 

[JIW]

Hi Was a bit confused about the Filters on my DO100 Pro, so I decides to measure the Filter Impulse responses of FL1 to FL7 settings:

My SMSL DO100 Pro with Firmware SMSL DO100PRO_MCU_V1.1_240925

Maybe some one can decode what they correspond to in the ESS datasheet for ES9039Q2M. The Linear Phase are not so easy to decode from my not so good images.

Im pretty confident about FL1, FL5, FL7

FL6 can either be Minimum Phase or Minimum Phase Fast Roll-Off

FL2, FL3, FL4 are Linear Phase, but not easy to visual decode from impulse response on scope.

Cheers
Flemming Bach
Denmark

FL1 (Minimum Phase Slow Roll-Off Low Dispersion)
View attachment 503044

FL2:
View attachment 503045
FL3:
View attachment 503047

FL4:
View attachment 503048

FL5: (Linear Phase Slow Roll-Off)
View attachment 503049

FL6:
View attachment 503050

FL7: (Minimum Phase Slow Roll-Off)
View attachment 503051

View attachment 503053

View attachment 503054

Those are correct. FL2 is Linear phase apodizing fast roll-off due to the lower frequency of the ringing since it rolls off earlier.

 

[Has420]

1st post on ASR, I have also upgraded the DO100 Pro to MCU 1.1 taken from SMSL's website. (do it at own risk, the firmware flasher shows weird characters as shown above)

I can confirm that the filter assignment is as per post #86 on this thread.

i.e.

FL1 - Minimum phase slow roll-off low dispersion (ESS #8)
FL2 - Linear phase apodizing fast roll-off (ESS #2)
FL3 - Linear phase fast roll-off (ESS #3)
FL4 - Linear phase fast roll-off low-ripple (ESS #4)
FL5 - Linear phase slow roll-off (ESS #5)
FL6 - Minimum phase fast roll-off (ESS #6)
FL7 - Minimum phase slow roll-off (ESS #7)

I have also attached the impulse response images that I captured for the individual filters, which were then compared with the impulse response characteristics shown in the DAC chip's datasheet.

Also, I found in another SMSL DAC's manual, the process to reset the DAC to default settings and can confirm that it works on the DO100 Pro too.

Switch the DAC off using the power switch on the back, press and hold the volume encoder on the front, and switch the power switch back on, once the unit powers up, you can let go of the volume encoder and the DAC will be back at default settings.

Kudos to the OP, learnt a lot due to this thread.

FL1

FL2

FL3

FL4

FL5

FL6

FL7

 

[Yviena]

Yes, I tried in both ways: first plugging the USB and then the power, and reverse. In the list of COM ports I didn't see any new device. I try restarting the notebook, reinstalling xmos drivers, nothing.

When I connect the USB without power, I see in device manager "USB Serial" with a exclamation mark. I'm not sure what I'm doing wrong.

EDIT: I still want to know which filter is the best for prominent low frequencys and more relaxed high frequencys. Using the default labels of the filters.

Unsure if you managed to ever update the firmware but for my d6s i had to install ch340 driver to get it to detect the dac.

 

[Alex_128]

Hi. I use SMSL DO 100 Pro. I bought it in December 2024. It is not possible to install the update MCU_V1.1_240925 (incomprehensible symbols appear). Please help me, is there any way to find out the installed firmware version of the DAC? Maybe this version is already installed. The firmware was released in September, and I bought it in December. Thanks for the interesting reviews.

 

[Pictus]

Hi. I use SMSL DO 100 Pro. I bought it in December 2024. It is not possible to install the update MCU_V1.1_240925 (incomprehensible symbols appear). Please help me, is there any way to find out the installed firmware version of the DAC? Maybe this version is already installed. The firmware was released in September, and I bought it in December. Thanks for the interesting reviews.

Try to install the driver. https://www.smsl-audio.com/upload/portal/undefined/SMSLUSBAudioDriver.zip

 

[Alex_128]

Thanks for the reply. Driver for XMOS v 5.74.0-2025-05-07 I have installed it. Problems with installing the MCU_V1.1_240925 firmware. Maybe there are ways to find out the firmware version by pressing the power button, encoder, or remote control? Thank you.

 

[Pictus]

Thanks for the reply. Driver for XMOS v 5.74.0-2025-05-07 I have installed it. Problems with installing the MCU_V1.1_240925 firmware. Maybe there are ways to find out the firmware version by pressing the power button, encoder, or remote control? Thank you.

I am glad to help, but I do not know and do not have the DAC.
I asked the AI:
Method 1: Using the Device Menu
You can view basic firmware information directly on the unit's display:

Access the Reset Menu: Use the control knob or remote to navigate to the last menu option, labeled "RESET".
View the Version: The screen typically displays a brief version number (e.g., v1.1) before you confirm a reset.
Note: This display often only shows major version numbers (two digits); it may not display more granular sub-versions.

Method 2: Using the XMOS Driver (Windows Only)
For a more detailed verification, especially for the MCU or USB DFU version, use the SMSL USB Audio Driver:

Connect to PC: Connect the DO100 Pro
to your computer via USB.
Open Control Panel: Open the S.M.S.L USB Audio Device Control Panel (installed with the drivers).
Check Status: Navigate to the "Info" or "About" tab. This will display the current firmware version of the XMOS USB interface.

Method 3: Startup Screen

Power Cycle: Turn the device completely off (unplugged or via the rear power switch).
Hold and Power On: Some SMSL models display the firmware version on the startup screen if you hold the control knob while turning the power back on.

 

[melowman]

Here's what I measured for the DO100 PRO - Output at 44.1kHz, sampling at 192kHz:

 

[melowman]

This is what I measured for the RAW-MDA1 DAC. It looks identical to the DO100 PRO above; and to the curves in the manual.

The manual and the DAC's menu have the correct labelling, except most probably Filters #1 and #7, which, according to the impulse response measurements of the DO100 PRO above, seem to be inverted -- if SMSL is consistent in its design. (I have no mean to measure analog impulse responses to verify this.)
Meaning:
Filter #1 is probably Minimum phase slow roll-off low dispersion (ESS #8)
Filter #7 is probably Minimum phase slow roll-off (ESS #7)