[PROBLEM] Problem with an SMSL M300SE DAC

[Tim Curtis]

@PeterLustig33 I would suggest contacting SMSL and provide them with the output of the commands below. They may be able to provide some insight into why the device is not being recognized.

Code:

# OS Info
/var/www/util/sysutil.sh "get-osinfo"

# Pi model revision
/var/www/util/pirev.py

# Audio devices detected
aplay -l

# USB device list
lsusb

[Nutul]

You have experimented with both the USB ports of the DAC, right?
I remember having read somewhere (ASR?) that on some devices the writing is incorrect, that is: they are reversed.
It should be power = (power + data) and aux-power = (power only, for when you use optical in, for instance, but the dac needs power anyway)

If you haven't already, try both ports.

One thing also, I remember my DAC is not recognized on the USB3.0 ports of the Pi; only on the 2.0, so you may want to try all 4 possible cases.

Fingers crossed, report ASAP.

[PeterLustig33]

You guys are great.

The hint from @Nutul did the trick. The stupid part is actually incorrectly / badly labelled.
 
As you can see in the attached picture, the USB audio goes into the "power port", the other USB port is free in my case. So both data and power run via this port.
I had already tried this port before, but nothing was displayed. (for whatever reason)

Restarting everything and plugging USB into the power port is the solution.

Thank you very much, you three.....

According to my initial tests, the sound of this DAC is really very good. (Raspi4 Moode Player -> DAC SMSL M300SL -> Amp Musical Fidelity B200X -> Speaker Rauna Leira of Sweden)

Now I just have a problem with the short pop when starting a stream.

[Nutul]

Now I just have a problem with the short pop when starting a stream.

When you start playing anything? It looks like ti is the same old story the DAC needs to open its stream, configure sampling-rate / bit-depth, and this causes clicks/pops...

Do you experience them also between tracks with same parameters? Or between tracks with different parameters? Or always? Or only with network streaming?

Try to have alook on ASR about pops with your DAC, maybe there is something; people there tend to be helpful.

[PeterLustig33]

I still have to test it carefully, my first impression is that the plopping noise always comes when Stream is opened. 
So far I have only tested with Moode Spotify, Airplay or Radio (Paradise). It only started working this morning. ;-)  Everything is quiet when running playlists. 
I'll test it again first and then do some research in the ASR forum.

[Nutul]

I still have to test it carefully, my first impression is that the plopping noise always comes when Stream is opened. 
So far I have only tested with Moode Spotify, Airplay or Radio (Paradise). It only started working this morning. ;-)  Everything is quiet when running playlists. 
I'll test it again first and then do some research in the ASR forum.

still weird... in this case I'd expect spotify and airplay to make the noise, not the radio (as the radio involves MPD, while the other two don't...)
But then again, keep it monitored; the more we know, the more we can do to fix it, as it affects many a dac out there, from what I hear...

[TheOldPresbyope]

@PeterLustig33 

I got to thinking late last night that "serial converter" was an odd generic name for the USB port controller chip so I looked up the part number. Totally wrong for an audio port. Sorry I didn't twig on this earlier but it never occurred to me that there may be more than one USB socket on the DAC. I was doing my probing in the wrong end of the elephant, so to speak.

Glad you got that part of the puzzle taken care of. Sorry to hear about the noise problem. Seems to be a recurring problem with certain DACs. I have nothing to contribute there.

Regards,
Kent

[PeterLustig33]

@Nutul: unfortunately I can't test the coaxial or optical input as I don't have any equipment for it. Via USB the noise occurs at every start AND every end of a stream. It is always a small "tock" followed by a slightly louder "tock". If the radio stream or the playlist continues, nothing happens. 

@TheOldPresbyope: no problem at all, it has been clarified. I was also misled by the 2 connections. I hope that this now helps others to find this error more quickly. That's one of the purposes of forums like this.

Basically, I have to say that I am delighted with the quality of the DAC. Previously I had an Allo Boss built directly into the Raspberry. The SMSL M300SE is much clearer, more spacious and more detailed.

[Nutul]

@Nutul: unfortunately I can't test the coaxial or optical input as I don't have any equipment for it.

Nowhere I mentioned those... although they probably have the same problem.

what I wanted to understand is:
1. playing an internet radio involves MPD
2. playing local files involves MPD
3. playing AirPlay streams does not involve MPD
4. playing Spotify via spotify-connect does not involve MPD

based on when/where the clicks happen we could understand whether MPD was behaving better, or the other stream engines were... it appears it is a problem of the DAC, which can be circumvented, but not as easily.
Also, IME, if you have a playlist with tracks of different sampling-rate/bitdepth, most probably you'll hear the clicks/pops even between the tracks, and not only at playlist/playqueue begin/end.

Definitely, AirPlay won't change sampling-rate/bitdepth, as it is supposed to resample everything at 16/48 (my bad, so it is, and as does Android by default without special players being used...)

Spotify, also is lossy, and at VBR, so I don't expect it to click/pop between tracks.

You can confirm or deny what i've written above, but don't hurry, I understand it is boring to do; moreover it is just to gather more information about the actual scenario, not that we can do anything about it, not at this point.

Meanwhile, if the clicks/pops are affected by the volume, I suggest you puti it to MIN/MUTE, start playback, and rise it. Although I believe they are caused by the speakers when the output stage gets engaged by the DAC, so to say... after the volume :-(
But you can always try, at least it keeps the doctor away from the speakers fo rlonger ;-)

[Tim Curtis]

Audio glitches that occur when play stops/starts are typically because the audio device does not include a "pop-suppression" circuit/feature. It's a non-trivial feature and so you won't see it in the lower price range and even some expensive devices don't have it or don't do it very well. My Allo Revolution DAC does have a nice pop-mute setting that controls the automate ESS chip option.

The only workaround I'm aware of in software is to keep the audio output open. Squeezelite has an option for this and maybe some other players do but MPD, AirPlay and Spotify Connect renderers do not. They close the audio output when playback ends. MPD has an exception to this though when automatically transitioning from one Queue item to another. It apparently keeps the audio output open in this case.