SMSL D300 Review (Balanced DAC)

[Anigma]

Interesting! I guess it is not about the broken one but about the working one running MCU fw 1.21.

- Yes, it is about the serviceable D300, which works with firmware 1.21 and USB firmware 1.30

Maybe USB fw downgrade could help with the broken one. Because upgrade to MCU 1.1 was provided together with USB fw upgrade to 1.30. But I don't know about public availability of original USB fw which worked with MCU fw 1.0

- Thought about it. In the faulty D300, the USB firmware is also updated, although after the update they show a strange version of 6F4. Rather, the USB firmware, which is flashed together with MCU 1.21, would help, the one that is offered on the site after downloading displays an incomprehensible version (I wrote above) and, accordingly, nothing works.

 

[v1adpetrov2]

Maybe USB fw downgrade could help with the broken one. Because upgrade to MCU 1.1 was provided together with USB fw upgrade to 1.30. But I don't know about public availability of original USB fw which worked with MCU fw 1.0.

The firmware MCU v1.00 works fine on my USB firmware v1.30.

I had to solder out a chip with a corrupted USB firmware, flash it in the programmer in v6F2 and solder it back.
After restoring the work of my DAC, I flashed the USB in v1.30 on top of v6F2 and flashed the MCU with a serviceable version 1.11 on top of v1.00
Clicks in some modes of operation remained, and I returned the MCU version 1.0
Since then everything works fine with PCM streams.
And I don't listen to DSD.

 

[bogi]

I had to solder out a chip with a corrupted USB firmware, flash it in the programmer in v6F2 and solder it back.

Thanks for interesting information! I am surprised you found USB fw to be corrupted. How does USB fw corruption happen in your case? What was your MCU fw and usb FW before your repair action? What does it mean v6F2 ?

Does it mean that MCU fw downgrade causes corruption of USB fw?
No chance to fix broken units without desoldering?

And I don't listen to DSD.

AKAIK MCU version 1.0 does not support DoP but it supports native DSD with Windows ASIO driver.

 

[v1adpetrov2]

Thanks for interesting information! I am surprised you found USB fw to be corrupted. How does USB fw corruption happen in your case? What was your MCU fw and usb FW before your repair action? What does it mean v6F2 ?

Does it mean that MCU fw downgrade causes corruption of USB fw?

I realized that you haven't read this topic from the very beginning.
Otherwise you wouldn't have these questions.
Everything is described in detail, starting from here.

The D300 has such a feature: it is possible to lower or increase the version of the MCU by flashing without the risk of turning the DAC into a "brick".
But it is impossible to lower the USB firmware version - get a "brick"!!!

That's what happened with me.
Thank you, a kind person helped me and shared a flash memory dump with the original factory firmware USB v6F2.
Therefore, it was possible to restore my D300 by carrying out procedures for dismantling the flash memory, flashing it in the programmer and mounting it back on the board.

 

[Anigma]

I had to solder out a chip with a corrupted USB firmware, flash it in the programmer in v6F2 and solder it back

I want to try at first without soldering, but for this you need to redo the programmer to 3.3 volts, so as not to kill XMOS with 5 volts, and unfortunately there is no full dump of the W25X40CLSNIG flash (winbond), I tried to pour similar dumps from XU208, but unfortunately it does not work, the addressing is different.

 

[bogi]

The D300 has such a feature: it is possible to lower or increase the version of the MCU by flashing without the risk of turning the DAC into a "brick".
But it is impossible to lower the USB firmware version - get a "brick"!!!

Thanks for explanation! I for sure don't remember all the details from this thread. But I think only one USB fw version was attached in this thread (SMSL D300_USB_DFU v1.3.bin). If new units are sold with this 1.3 version, how could people downgrade USB fw version and thus brick their device?

Edit: I see Anigma wrote that USB fw is up(down)graded together with MCU fw. Does the MCU fw update tool allow not to choose USB fw update as part of the update procedure?

Does this mean, that for example a new unit, having USB fw 1.3, can be safely downgraded to MCU fw 1.0 with the file IAP_D300_MM32_1v0.hex attached in this thread, if USB fw will not be changed by an explicit action?

For people, who don't need DoP, I assume native DSD with Windows ASIO driver should work without DoP with MCU fw version 1.0.

 

[v1adpetrov2]

Does this mean, that for example a new unit, having USB fw 1.3, can be safely downgraded to MCU fw 1.0 with the file IAP_D300_MM32_1v0.hex attached in this thread, if USB fw will not be changed by an explicit action?

Well, I downgraded the IAP to version 1v0, and the USB DFU remained v1.3
And everything works fine.

 

[bogi]

Well, I downgraded the IAP to version 1v0, and the USB DFU remained v1.3
And everything works fine.

After reading your latest posts, it looks to me:
- Applying IAP_D300_MM32_1v1.hex (SMSL D300_MCU_FW 221012) with ispV2.4.exe downgrades MCU fw to 1.1. If USB DFU was v1.3 before then it causes USB DFU to show v6.F2 and the result is bricked device.
- Applying IAP_D300_MM32_1v0.hex with ispV2.4.exe downgrades MCU fw to 1.0 and leaves USB MCU fw untouched. It does not brick the device.

Are my assumptions correct? Are here any people who applied IAP_D300_MM32_1v0.hex without previously applying IAP_D300_MM32_1v1.hex and the result was bricked device?

 

[v1adpetrov2]

Are my assumptions correct?

Unfortunately, you are very wrong.
The D300 is flashed with TWO different firmware and with the help of TWO different utilities.
Using the utility XMOSUSBDACDfu.exe we are flashing XMOS USB DFU (file SMSL_D300_USB_DFU_v1.3.bin).
Using the utility ispV2.4.exe we flash the MM32F103 processor, which controls the ROHM BD34301EKV DAC-chip and displays information on the screen (file IAP_D300_MM32_1v11.hex).
The first copies of the DAC went on sale with the USB DFU v6.F2 versions and with the IAP 1v0 version.
Then, the "update" 1v1 (_Firmware__221012_) was posted here, which contains a buggy IAP 1v1 and a working USB DFU v1.0.
I installed these "updates" and got a personal little HELL!

 

[Alex Ma]

Hello! The appearance of clicks when playing audio through the SMSL D300 did not appear immediately, which is strange. I scrolled through this forum and tried to look for a solution in other places. The seller suggested that I send the device to him for repair, I decided that this was expensive and not practical. I contacted smsl-mandy, tried to install new firmware, but my DAC would not even enter firmware mode. A miracle happened when I connected it via IFI ZenStream instead of my computer - the clicking noises during music playback disappeared, although the clicks remained when switching tracks.
I sold this streamer, but came to the conclusion that the problem was not a software of the DAC, but the lack of galvanic isolation in the USB port of the DAC, as well as the USB output of the playback device, which can introduce electrical interference and noise through the USB port.
This was easily confirmed, I bought two very inexpensive USB isolators on Aliexpress and it was indeed confirmed - there is no noise. A new problem has arisen: the DAC cannot receive a signal higher than DSD 64 through these USB filters, and my new theory, in which I am more than confident, is that purchasing an optical USB cable will completely remove all remaining questions. It is very inconvenient that optical cables are no shorter than two meters, but I think that all of us, who like the D300 DAC's sound can live with this inconvenience.

 

[bogi]

Unfortunately, you are very wrong.
The D300 is flashed with TWO different firmware and with the help of TWO different utilities.
Using the utility XMOSUSBDACDfu.exe we are flashing XMOS USB DFU (file SMSL_D300_USB_DFU_v1.3.bin).
Using the utility ispV2.4.exe we flash the MM32F103 processor, which controls the ROHM BD34301EKV DAC-chip and displays information on the screen (file IAP_D300_MM32_1v11.hex).
The first copies of the DAC went on sale with the USB DFU v6.F2 versions and with the IAP 1v0 version.
Then, the "update" 1v1 (_Firmware__221012_) was posted here, which contains a buggy IAP 1v1 and a working USB DFU v1.0.
I installed these "updates" and got a personal little HELL!

Thank you for the information provided! I still do not understand what has MCU (IAP) update to do with USB DFU fw and v6.F2. Why did you need to reflash USB DFU fw? How could MCU fw destroy your DFU fw? That's unclear for me, how it happened.

If I understand you correctly, the only problem is MCU 1.1 (IAP 1v1) and users of new units can (if they want) downgrade to MCU 1.0 (IAP 1v0), which works without clicks.
If so, the main downside of downgrading to IAP 1v0 then seems to be the inabililty to return to the current firmware (probably 1.21), which was not posted as IAP*.hex file.

 

[bogi]

I bought two very inexpensive USB isolators on Aliexpress and it was indeed confirmed - there is no noise. A new problem has arisen: the DAC cannot receive a signal higher than DSD 64 through these USB filters

You could ask here before buying those isolators, I would recommend you Topping HS01 or HS02 which work up to DSD512. I'm using HS02 about a year already.

 

[bogi]

I received my D300 today. Shipment from China to Slovakia took 15 days. I ordered it from hifi-express.com and I paid 328 EUR.
I am listening already about 3 hours and I am pleased with the sound. I am interested only in direct DSD mode with HQPlayer. With suitable HQPlayer oversampling filters and delta sigma modulators sound is dynamic and there is no lack of deepest bass impact. But yes, with other settings it may sound like without deepest bass and lifeless. I understand that in PCM mode and with too relaxed amp it may sound lifeless like smaller part of owners reported here (most are pleased with the sound). With HQPlayer it sounds wonderfully.

What positively surprised me is the ability to play 48k based DSD rates. 24.465MHz (512x 48k) is possible with this DAC. 48k based DSD rates are suitable for 48k based PCM content playback in HQPlayer since integer upsampling ratio requires less computational power.

Clicks don't look as serious issue in my DSD mode of operation. I perceived no loud pops, maybe because of galvanic isolation I am using. I observed a mild click on playback start (nothing really serious), but then in album mode or playlist mode no click occured anymore between tracks. Maybe I will try the USB driver posted by Anigma on the previous page, but also the current state bothers me only little. I understand that people who don't upsample and mix different PCM sample rate tracks in playlist may perceive things differently.

 

[Alex Ma]

You could ask here before buying those isolators, I would recommend you Topping HS01 or HS02 which work up to DSD512. I'm using HS02 about a year already.

Thank you. Perhaps you are right, what confuses me a little about the devices you write about is that the manufacturer does not describe the operating principle of the device, while devices based on ADUM chips are quite widely known, although they have a problem with bandwidth. I have already ordered an optical cable and will definitely write about the results; the cost of the devices (Topping and optical cable) is approximately equal to each other. I probably didn't read the forum well and missed any mention of USB filters, so I spent a lot of time looking for a simple solution. In this case, I see no point in updating the device software in an extremely inconvenient way.

 

[bogi]

devices based on ADUM chips are quite widely known, although they have a problem with bandwidth

There are newer ADUM chips used in HS02. Find HS02 specific thread and also HS02 product info.
If manufacturer tells 'high speed' or 480 MB/s, then it will support UAC2 for >96k PCM and DoP >DSD64 as well as high rate DSD in a non-UAC2 compliant form called 'native DSD'.

 

[Alex Ma]

There are newer ADUM chips used in HS02. Find HS02 specific thread and also HS02 product info.
If manufacturer tells 'high speed' or 480 MB/s, then it will support UAC2 for >96k PCM and DoP >DSD64 as well as high rate DSD in a non-UAC2 compliant form called 'native DSD'.

Yes, if my experiment with an optical USB cable that supports USB 3.0 (which will allow it to be used in the future for higher bitrates) does not suit me, I will turn my attention to the filter from Topping. It’s a pity that I didn’t see or notice such a solution in this forum, like: “if you have clicks in the D300, just install a USB filter.” I had to go the extra mile from contacting the seller, the SMSL representative, and trying to flash the firmware. Everything turned out to be much simpler)

 

[Anigma]

In general, so... By tedious experiments, such conclusions were obtained - in the latest D300, which come with MCU 1.21, something has been changed that lowering the firmware version completely kills the output - there is no sound at the output regardless of which input the signal is being sent from, and the DAC itself works correctly at the input, that is, it correctly detects all incoming to it signals (PCM, DSD etc.) To restore performance, only the MCU 1.21 is needed and where to get it is a big question. In general, who has a revision from 1.21 in any case, do not lower the MCU - you are guaranteed to get a "brick" without the possibility of recovery. USB does not affect this process in any way (in extreme cases, it is restored without problems by the programmer), there is no sound for another reason, alas.

Why did you need to reflash USB DFU fw?

- In my case, I started doing this after I lowered the MTU from 1.21 to 1.0, because the sound disappeared and I thought that USB firmware would help in this case, but as it turned out, this is not at all the case - the downgrade from 1.21 turns into a brick. ..

 

[bogi]

In my case, I started doing this after I lowered the MTU from 1.21 to 1.0, because the sound disappeared and I thought that USB firmware would help in this case, but as it turned out, this is not at all the case - the downgrade from 1.21 turns into a brick. ..

So ... you did 1.21 to 1.0 and got a bricked device.


But v1adpetrov2 wrote:

The D300 has such a feature: it is possible to lower or increase the version of the MCU by flashing without the risk of turning the DAC into a "brick".
But it is impossible to lower the USB firmware version - get a "brick"!!!

Well, I downgraded the IAP to version 1v0, and the USB DFU remained v1.3
And everything works fine.

It's confusing when I attempt to join your and v1adpetrov2's information together.
My basic question on this page was: Is it safe to downgrade 1.21 directly to 1.0 without risk of bricking the device?
From v1adpetrov2's answers it looks to me that downgrade only to MCU 1.1 causes the trouble but not to 1.0.
But your answer indicates that you went to 1.0 directly without 1.1 as a middle step and you still got a bricked device.
It would be helpful for others if you two could get to the same conclusion.

 

[Anigma]

So ... you did 1.21 to 1.0 and got a bricked device.

- Please note that I am talking about the fact that it is the downgrade from 1.21 to 1.1 and 1.0 that leads to the brick. Who originally had version 1.0 and they upgraded it to 1.1 and then rolled it back to 1.0, there are NO problems! The problem is that the new versions of the D300 from 1.21 have something that is incompatible with the old firmware. v1adpetrov2 originally had the D300 with firmware 1.0

 

[bogi]

- Please note that I am talking about the fact that it is the downgrade from 1.21 to 1.1 and 1.0 that leads to the brick. Who originally had version 1.0 and they upgraded it to 1.1 and then rolled it back to 1.0, there are NO problems! The problem is that the new versions of the D300 from 1.21 have something that is incompatible with the old firmware. v1adpetrov2 originally had the D300 with firmware 1.0

Did you do 1.21 -> 1.1 -> 1.0 or directly (in one step) 1.21 -> 1.0 ?