SMSL M500 - Owners' Thread

[Jimbob54]

Thanks a bunch for this info. I chatted with them on Amazon and they said to update the firmware... I will try to get the newest M500 from SMSL.

My unit is dated 2019-07-28

My remote just stopped working, too. :/

Press c on the remote

 

[Veri]

Hi. A bit of an update.

1) We have been contacted by Kelly and their engineering manager. Last week, forwarded a laundry list of questions to them to better understand the design of this box.

2) This weekend, received a dump of the v2.01 firmware that is stored inside the flash memory device (8 pin device) shown on the PCB somewhere in this forum. The clean idea is to replace this IC with another that contains this corrected firmware. However, this requires the use of hot air surface mount tools + opening the box. If practical, consider to do so with your local electronic repair shop. The memory device is very common and the programming is straight forward (QSPI flash memory @ 4Mb).

3) This v2.01 firmware is reported to contain the fixed bootloader & the latest firmware for your M500 box. That is, with this firmware, future upgrades will not face this quirk.

4) Waiting on the answers for our many questions but know that the XMOS document raised (my first post here on this forum) is the root cause. One of the questions is how to properly open the box.

5) We do not own this M500 box but trying to understand and simulate the environment with our assorted XMOS tools in the lab. The upgrade mechanism is also very restrictive on what can and cannot be done with the upgrades.

6) Just now forwarded an email with a potential idea to SMSL (see below). IF you have not performed an upgrade, do not do so unless you are confident that your box has the corrected FACTORY IMAGE with the corrected bootloader. Only SMSL can validate which boxes or firmware offer this corrected firmware. Have emailed them to ask at which firmware version was this code corrected.

If your box contains the buggy bootloader and an older factory image AND you have not performed any upgrades then in theory, it should be possible to fix the box using only software.

It should also be possible to fix such field units using software as follows:

create an UPGRADE image that will boot -> remove the write protect bits of the flash -> erase the factory supplied (old) bootloader + erase the Image "0" (aka factory image) -> write the contents of the 2.01 firmware as the factory image - all in a single pass.

This must be all done without a power failure else the unit will brick. Then only a hardware fix of replacing the flash will work.

So the concept is that this single time upgrade can be used as a mechanism to fix the factory firmware so that the issue is fixed by the end consumer. This is a very solid potential solution.

We are confident that the firmware is encrypted so this demands that SMSL must encrypt this special firmware so that upon boot, the secret keys inside the XMOS CPU can decrypt the upgrade image during runtime to perform this task. Unless the secret keys are used, the code will not boot.

Not clear if other SMSL widgets are impacted by this field upgrade bug. If it makes business sense, will consider to purchase a M500 to review this case and then resell afterwards. Ironically then would prefer an older (buggy) firmware unit.

Back to research...

Sorry - forgot to note that SMSL has noted that the M500 is NOT EOL in the last email.

Appreciate the research you are doing

 

[Mitch1200]

Just got my SMSL M500 (SW 1.6, WH 1.3, 2020-3-2) and am very pleased with the sound through HD-650s. In the hopes of discerning a difference between MQA files and the non-MQA equivalent, I've compiled a playlist of MQA and non-MQA tracks in Tidal and in Tidal through Roon. [The MQA files may or may not sound better to me--haven't done enough work on it yet.] But one big difference between MQA and non-MQA tracks in Tidal through Roon is that the MQA title plays for about 100 msec followed by about 200 msec of silence followed by the rest of the track. It takes that full 300 msec for the MQA label to appear on the M500 screen. [All times approximate.] It sounds like a stutter. In Tidal directly, there's simply about 300 msec of the initial part of the title skipped. No stutter, just lost info. I'm assuming that the DAC needs an initial sample of the track in order to determine how to process it, but it's very noticeable and distracting. Or maybe it's something I've done. I've tried all the combinations of decoding/rendering within the two apps that I could think of, all without success. Has anyone else experienced this? Any suggestions on how to fix it? Apologies in advance if this is not the forum/thread to post this. Thanks. Mitch

 

[Veri]

Just got my SMSL M500 (SW 1.6, WH 1.3, 2020-3-2) and am very pleased with the sound through HD-650s. In the hopes of discerning a difference between MQA files and the non-MQA equivalent, I've compiled a playlist of MQA and non-MQA tracks in Tidal and in Tidal through Roon. [The MQA files may or may not sound better to me--haven't done enough work on it yet.] But one big difference between MQA and non-MQA tracks in Tidal through Roon is that the MQA title plays for about 100 msec followed by about 200 msec of silence followed by the rest of the track. It takes that full 300 msec for the MQA label to appear on the M500 screen. [All times approximate.] It sounds like a stutter. In Tidal directly, there's simply about 300 msec of the initial part of the title skipped. No stutter, just lost info. I'm assuming that the DAC needs an initial sample of the track in order to determine how to process it, but it's very noticeable and distracting. Or maybe it's something I've done. I've tried all the combinations of decoding/rendering within the two apps that I could think of, all without success. Has anyone else experienced this? Any suggestions on how to fix it? Apologies in advance if this is not the forum/thread to post this. Thanks. Mitch
View attachment 68909View attachment 68913

I assume it's the DAC decoding the data, seeing it is MQA and enabling MQA mode each time. Maybe mail SMSL support about this issue?

 

[newguy358]

Interested in the M500, just have a couple questions for owners before I make the jump.

• Is the line-out volume fixed or can it be adjusted via volume knob? Can the user choose fixed or controlled volume?
• Can the headphone-out and line-out be used at the same time? Can they be used separately?
• If the headphone-out and line-out can be used at the same time, does the volume control affect both or are they independent?

 

[Mitch1200]

I assume it's the DAC decoding the data, seeing it is MQA and enabling MQA mode each time. Maybe mail SMSL support about this issue?

I think that's right. I'll follow up with SMSL. Thanks. Mitch

 

[Jimbob54]

Interested in the M500, just have a couple questions for owners before I make the jump.

• Is the line-out volume fixed or can it be adjusted via volume knob? Can the user choose fixed or controlled volume?
• Can the headphone-out and line-out be used at the same time? Can they be used separately?
• If the headphone-out and line-out can be used at the same time, does the volume control affect both or are they independent?

https://www.audiosciencereview.com/...l-m500-dac-and-hp-amp-review.9606/post-430423

Answered in the other thread

 

[bobby1945]

How do we maximize the M500 capability?
I am using a new laptop and streaming exclusively TIDAL MQA files - My USB cable is a Supra 2.0 ( Significant improvement from SMSL supplied cable) But have I short changed myself ? some really expensive USB cables available (Curious) and making wild claims.
I have AuioQuest Red River XLR cables hooked up directly to my active speakers -Elac Navis ARB -51.
A simple set up.
But I am frustrated by some of the TIDAL audio files . Some display significant distortion ( jitter maybe ) or is it the original recording ?
Simple vocals eg Norah Jones sounds sublime , but more complex music eg Supertramp can get out of control sometimes.
The speakers display absolutely no noise when M500 at full volume .
I have no line conditioning and live in a condo , so maybe I am getting corrupted power supply.
Any comments.

 

[Jimbob54]

How do we maximize the M500 capability?
I am using a new laptop and streaming exclusively TIDAL MQA files - My USB cable is a Supra 2.0 ( Significant improvement from SMSL supplied cable) But have I short changed myself ? some really expensive USB cables available (Curious) and making wild claims.
I have AuioQuest Red River XLR cables hooked up directly to my active speakers -Elac Navis ARB -51.
A simple set up.
But I am frustrated by some of the TIDAL audio files . Some display significant distortion ( jitter maybe ) or is it the original recording ?
Simple vocals eg Norah Jones sounds sublime , but more complex music eg Supertramp can get out of control sometimes.
The speakers display absolutely no noise when M500 at full volume .
I have no line conditioning and live in a condo , so maybe I am getting corrupted power supply.
Any comments.

The answer likely does not lie in your equipment but the source files. If you turn your speakers up to full with everything on but musc paused and you hear nothing, doubtful anything wrong with you.

Does the "distortion" present when you turn the SMSL volume down(reducing the output to your speakers) but turn the speakers up to compensate? Outside chance the high output from the XLRs on earlier M500s (which got up to 7v) might be clipping but doubtful.

My money is on the recordings. I hear all manner of fuzz, blips and junk on my playback that is present on all DACS and amps and headphones i play on. Find a clean, well done recording and turn it up. Try a track from Steely Dan Aja or similar . Or , tell me the track you hear distortion on, link me to the tidal file and what you think the noise is, I will check

 

[Eetu]

My USB cable is a Supra 2.0 ( Significant improvement from SMSL supplied cable) But have I short changed myself ? some really expensive USB cables available (Curious) and making wild claims.

It may be that your system is a bit more transparent now and doesn't flatter bad recordings (MQA doesn't mean the actual recording is well made).

In any case, I would not waste more money on expensive USB cables.

 

[bobby1945]

The answer likely does not lie in your equipment but the source files. If you turn your speakers up to full with everything on but musc paused and you hear nothing, doubtful anything wrong with you.

Does the "distortion" present when you turn the SMSL volume down(reducing the output to your speakers) but turn the speakers up to compensate? Outside chance the high output from the XLRs on earlier M500s (which got up to 7v) might be clipping but doubtful.

My money is on the recordings. I hear all manner of fuzz, blips and junk on my playback that is present on all DACS and amps and headphones i play on. Find a clean, well done recording and turn it up. Try a track from Steely Dan Aja or similar . Or , tell me the track you hear distortion on, link me to the tidal file and what you think the noise is, I will check

OK
I have played the first 3 tracks of Aja -16/44 . Vocals extremely unpleasant to listen to on all 3 tracks.Instruments not so.
Then I played Hey Nineteen from Guacho- 24/96 MQA -Familiar with this track as was my reference when setting up my Linn LP12
Perfection - except some slight distortion on the word "MAKE tonight a beautiful Thing"

 

[Jimbob54]

OK
I have played the first 3 tracks of Aja -16/44 . Vocals extremely unpleasant to listen to on all 3 tracks.Instruments not so.
Then I played Hey Nineteen from Guacho- 24/96 MQA -Familiar with this track as was my reference when setting up my Linn LP12
Perfection - except some slight distortion on the word "MAKE tonight a beautiful Thing"

I will try the gaucho track first as its a specific reference

 

[Jimbob54]

I will try the gaucho track first as its a specific reference

Proof of absolutely nothing, I didnt get a whiff of distortion on the gaucho vocal reference . Nor on the Aja tracks, and I compared the Aja Tidal to my FLAC CD rip of the same. . Im not going to criticise Steely Dan's mixing decisions but I hear nothing wrong within my system. Sorry, not much help I'm afraid

 

[bobby1945]

Proof of absolutely nothing, I didnt get a whiff of distortion on the gaucho vocal reference . Nor on the Aja tracks, and I compared the Aja Tidal to my FLAC CD rip of the same. . Im not going to criticise Steely Dan's mixing decisions but I hear nothing wrong within my system. Sorry, not much help I'm afraid

I appreciate the time you have given.

 

[bobby1945]

I am continuing to detect clipping distortion on some TIDAL streams and supported by analysis Audacity .
Nevertheless , I have changed out the power cord to the M500 with a AQ NRG -Y2 and included a AQ Niagra 1200 power conditioner in the system.
The PC has just been replaced and significant improvement on the old SMSL supplied piece of wire.
Once again I return to Gaucho and Hey Nineteen -How sweet it sounds . Very vinyl
I am now a firm advocate of the up grading of power cords.
Ignore any negative comments on the replacement of PC-Just do it

 

[Veri]

I am now a firm advocate of the up grading of power cords.
Ignore any negative comments on the replacement of PC-Just do it

Uh-huh yeah I'll pass. Never have, never will and have yet to come across any issue. What a leap of faith to go from a clipping issue to buying $1000 of power supply nervosa peripherals . . .

 

[Jimbob54]

Uh-huh yeah I'll pass. Never have, never will and have yet to come across any issue. What a leap of faith to go from a clipping issue to buying $1000 of power supply nervosa peripherals . . .

Think I'd have dialled the dac output down a bit first, see if that got rid of the rough edges. Rule clipping in or out and if not clipping, figured out what was wrong in existing components. Dirty power would be heard more as interference /buzz than harsh edges to sound/ music wouldnt it?

 

[bobby1945]

The AQ Niagra was not expected to resolve the clipping issue-I live in Thailand , in a high rise condo and poor power supply is a way of life.
I have tried all combinations of DAC and TIDAL output levels -The end result is always the same
I am now 99% convinced, the clipping distortion is embedded in some TIDAL audio streams.
The distortion is only present in some passages of some streams. But it is horrific when it occurs.
Generally in a choral background to the primary singer - Could be a secondary track recording maybe?
Aretha Franklin for example -Her voice is crystal , then the backing group comes in with the chorus -Distortion!
Sourced the same track online and downloaded a FLAC file onto a USB stick.
Played audio file with potplayer +LAV audio codec . Same distortion on chorus.
Transferred FLAC file to RAM Drive on laptop -To bypass USB port.
Same result -Distortion.
I don't have a CD or vinyl of the album or even the kit to play .
The only conclusion I can come to is that the original recording or mix is in fact flawed.
Could it be that the system I am using is too revealing too transparent ?

 

[Veri]

I am now 99% convinced, the clipping distortion is embedded in some TIDAL audio streams.

Yeah, I think so too from the looks of it.. How silly to encode HQ audio just to have artifacts or (intersample) clipping to occur. Perhaps streaming over Roon can solve your issues.

 

[Jimbob54]

The AQ Niagra was not expected to resolve the clipping issue-I live in Thailand , in a high rise condo and poor power supply is a way of life.
I have tried all combinations of DAC and TIDAL output levels -The end result is always the same
I am now 99% convinced, the clipping distortion is embedded in some TIDAL audio streams.
The distortion is only present in some passages of some streams. But it is horrific when it occurs.
Generally in a choral background to the primary singer - Could be a secondary track recording maybe?
Aretha Franklin for example -Her voice is crystal , then the backing group comes in with the chorus -Distortion!
Sourced the same track online and downloaded a FLAC file onto a USB stick.
Played audio file with potplayer +LAV audio codec . Same distortion on chorus.
Transferred FLAC file to RAM Drive on laptop -To bypass USB port.
Same result -Distortion.
I don't have a CD or vinyl of the album or even the kit to play .
The only conclusion I can come to is that the original recording or mix is in fact flawed.
Could it be that the system I am using is too revealing too transparent ?

Buy one track from a good hi res source or even a 16/44 that you know the distortion well on tidal. Rule out the actual recording. Or rule it as the cause definitely