PMG Signature 512 DAC streamer BUG with DSD

Audio Components DACs
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Paul and PS Audio streamer guys,

I’ve finally finished struggling with streaming from my NAS to the DAC streamer via JPlay or mConnect. It was very frustrating when the streamer would eventually, or immediately, go into the tank when receiving files via DLNA/UPnP, necessitating a restart. Restarting was often wonky—it would hang “Initializing” forever, or I couldn’t switch inputs via the remote, or it would complete initializing then spin again, necessitating power-cycling the DAC. The randomness suggested a buffer overrun, but I didn’t know why this was happening seemingly at random.

It turns out that if I’d paid closer (or any) attention to the format of the files I was requesting, I’d have noticed that the issue is that the DAC’s streamer apparently doesn’t understand native DSD/DSF files, but requires them to be transcoded into DOP. That’s fine if you know it, but having the streamer not check for invalid input and instead splatter itself on the windshield is something that should likely be fixed. Or, if it’s supposed to work, that should be fixed.

Anyway, now that I’ve told Minimserver to transcode DSF to DOP, streaming directly to the DAC is working much better.

— Chris

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PMG 512 DAC first impressions
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I feed it many native DSD via roon. No DOP needed.

Does DLNA/UPnP does not support native DSD.

from google

No, DLNA/UPnP does not natively support native DSD in most cases

; it typically relies on DSD over PCM (DoP), which wraps the DSD data inside a PCM stream. Some server software and renderers can be configured to send native DSD, but it depends on the specific hardware and software setup.

Why DLNA/UPnP struggles with native DSD

  • Protocol limitations: The standard DLNA/UPnP protocol was not designed for the unique data stream of native DSD.

  • DoP as a workaround: To get around this, DoP was developed. It packages the DSD signal within a standard PCM stream, but this still requires the receiving DAC to be able to recognize and unfold the DoP stream.

  • Server and renderer dependency: Support for native DSD depends on the software acting as a server (like JRiver or AssetUPnP) and the software or hardware acting as a renderer (like a dedicated streamer or a computer with a connected DAC) being able to handle native DSD and being configured to do so.

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Disclaimer: I’m not an expert on this stuff

Brian,

DSD being sent from my NAS isn’t actually raw DSD—a string of ones and zeroes at the correct frequency, which is not possible to send over IP-based networks—but an encoded version called DSF, which is. Minimserver sends this without difficulty, but apparently the DAC streamer’s rendering software (gmediarender 0.3) doesn’t recognize this format. The problem, to me, is twofold. First, the user’s guide for the DAC doesn’t say much about what the renderer accepts in terms of media types; and second, the renderer crawls into a hole when it gets a DSF file.

Your Roon server likely sends DSF files to its comrade Roon endpoint in the DAC, or maybe it transcodes them to DoP. If neither is the case, refer to my initial disclaimer.

— Chris

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The lack of documentation is a drag, but just to remind folks that wrapping DSD in a PCM stream (called “DoP” = “DSD over PCM”) is not transcoding, and not altering the bit stream data, and should be transparent (apart from any difference in internal noise generated by CPU cycles etc. unwrapping the PCM stream).

In networking analogy terms it is rather like transmitting IP packets wrapped up in ethernet “packets” (a.k.a. frames if I recall correctly).

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Yes I have ripped over 100 SACDs and bought many albums for download in DSF. It can be fed directly into the PMG 512. But not using the DLNA/UPnP protocol. You need a different method. Mine are stored on a NAS just like yours and Roon reads it right off it and streams to the DAC. Try a different method.

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Well, it’s a lossless transcoding, but the issue isn’t about semantics. It’s about the fact that the PMG streamer becomes non-functional when fed something it doesn’t understand.

—Chris

—Chris

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I am! I’m using DoP.

—Chris

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True. But I just wanted to make sure people understood, its not the DAC its the use of DLNA/UPnP forcing you to use that workaround.

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Not to be a stickler, but @joma0711 is correct. DSD over PCM (DoP) is not transcoding in the usual sense of converting one audio format to another that alters the audio data itself. Instead, DoP is a method of encapsulation that packages the raw DSD data into a PCM framework for transmission.

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Basically you are saying (I think Ted Smith used to say it too) that DoP is lossless with DSD. That is really the key, if the same signal gets there and sounds the same, who cares how.

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Yes, Ted would phrase it as an encapsulation as well.

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I don’t care so much about having to use DoP; I just wish I’d known about it sooner.

What’s really important, I think, is that the DAC streamer has a bug that should be, and most likely will be, addressed. PS Audio, not being primarily a software company, understandably doesn’t have a well-defined protocol for bug submissions. I chatted with Delia previously and told her about my issue with the streamer crashing and what little data I had before I knew what was causing it. Now that I do know, I’d thought reporting it on this forum would provide the solution to anyone else having the same difficulty and bring it directly to the attention of PS Audio.

I didn’t anticipate that it would result in a disagreement over semantics and a mild plug for the superiority of Roon over DLNA/UPnP. And it is the DAC, insofar as the streamer is part of the DAC, that’s forcing the workaround. As you’ve said, your Roon server is sending DSF files to the streamer. UPnP has no problem doing the same, but the renderer for that protocol isn’t as adept at handling this as the Roon endpoint code in the steamer.

—Chris

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First off, yes the streamer section had issues. I was one of the first 25 and felt it the hardest. Its not done yet as Roon certification is not yet there, but coming. This is out of their hands and in the Roon Queue. All the companies deal with this. Was this DAC released a bit early, yeah. But that is PSA, they have pretty much done that and only released 25 to early adaptors just for that reason. I knew what I was getting into.

The Data issue Delia spoke of was swapping sample rates. In fact in my testing playing a DSD 64 (SACD) native always seemed to get the DAC on track and stop the skipping. But if I one song followed by another in some higher format (yes PCM too) it would make the skipping come back. That has all been worked out and has nothing to do with the DSF ability of the DAC. The DAC for sure handles DSF files, it needs the right software. NO DAC can get DSF native over DLNA/UPnP. See my google search above. Its not the DAC making you do DoP, its DLNA/UPnP. That is a known long before this DAC was on the market. In the end its a wash for you as DoP solves it, but its certainly not the DAC causing it, its the protocol.

BTW its not a plug for Roon. Thats my choice. Many here love JPlay. Others Audirvāna, and some choose to put a streamer in front to use its software (lightning for example). Its a choice, not a limitation of the DAC.

Now if you want to say PSA does not offer native software as part of their package, then yeah, thats something to take into consideration when buying it. They are not a software company, I do not blame them. Eversolo probably has as many coders as they do employees. I know many would love to just plug in a USB device and stream the media. They just do not do that. They rely on other software in order to stream with their device.

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As we all know by now, when relying on the veracity of information gleaned from the internet our mileage may vary. Was your result correct? Perhaps it was. Here, though, is an alternative view from my Google search:

Yes, UPnP can send a DSF file, but it depends on the capabilities of the server, the renderer, and the specific configuration of the UPnP connection. The ability to play DSF files natively without transcoding is not guaranteed and often requires specific settings or server software like MinimServer, which may require manual configuration of MIME types.

—Chris

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That is not the DAC.

  • Server and renderer dependency: Support for native DSD depends on the software acting as a server (like JRiver or AssetUPnP) and the software or hardware acting as a renderer (like a dedicated streamer or a computer with a connected DAC) being able to handle native DSD and being configured to do so.

The 512 handles Native DSD. it can take it from I2S, USB, and via its streamer. JRiver can do it. Never heard of AssetUPnP or MinimServer.

Not trying to get into an argument over semantics, but this above is only what I am trying to talk about. That is 100% not true. it does NOT require to be translated to DoP. It supports BOTH native and DoP but its 100% software dependent. Some software can send native and some cannot do it without it first being encapsulated by DoP. Thats all I am saying.

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I don’t care that gmediarender, the open-source UPnP renderer embedded in the PMG DAC streamer, can’t accept a DSF file and send its DSD payload directly to the DAC. Obviously, the Roon bridge software hosted in the streamer hardware can do that. I can, easily it turns out, have Minimserver reformat a DSF file to a DoP file on the fly, which in turn results in gmediarender extracting the little chunks of DSD, combining them into a DSD stream, and sending that on to the DAC.

I sorta care that the DAC documentation doesn’t tell buyers or potential buyers that you have to send DoP over UPnP if your music is DSD. That information would save perplexed users a phone call or a forum search or a lucky guess.

I really care that sending DSF, and potentially other unrecognized formats, to the DAC streamer over UPnP causes it to malfunction until it’s rebooted. That should be fixed, and I have no doubt that it will be now that PS Audio, hopefully, knows about it. In fact, I’ll call Delia shortly to make sure.

—Chris

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I will agree with this one.

yes a reboot should not have to happen. error message at best…but not reboot.

I am not an expert on most other DACs, but I think most do not work with DSD over UPnP without help on the software side. I could be wrong. Should be documented much better and not lock up though.

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Apologies, was not arguing semantics, just ensuring others reading this thread (who may not be familiar with the details of DSD) were aware of the “lossless” nature of DOP :slight_smile:

You’re correct though in that the streamer should gracefully handle any error or stream it doesn’t recognise, and I sincerely hope (and assume) it will be fixed by PSA.

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No worries; I understood that to have been your point. I may well have misused the term “transcode”, and had you not commented an entirely other tangential discussion regarding lossy vs. lossless encoding might have ensued.

—Chris

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20

Sigh. I’m done with the PMG 512’s streamer.

Admittedly, Qobuz Connect works well, and if that were my only music source I’d be content. However, I also have a local DLNA/UPnP server that has, for the last eleven years, housed the music I own. I’d optimistically hoped to also use that as a source for the PMG’s streamer, but I’ve now thrown in the towel and accepted defeat from a superior opponent. The streamer is now powered >off<. Take that.

At first, the streamer would quickly or eventually stop functioning and would affect the DAC negatively in various, seeming random, ways—the topic of this thread. I naively thought I’d finally solved all my streamer problems by having my DLNA server convert DSF files to DoP on the fly. In fact, that seemed to work quite well. Until…

…I cued up a DSD256 track for the first time last evening, and it played okay at first but then began skipping throughout. I doubted the problem could be a laggy server, a (stupidly fast) M4 Mac Mini/SSD combo, but I figured I’d listen to Qobuz and check later. But Qobuz Connect no longer worked. Playing an album consisted of watching the progress dot quickly and noiselessly scan through the first track, then the second, then all following tracks until the album was complete, elapsed time maybe ten or fifteen seconds. Exiting and restarting the app didn’t help, but power-cycling the streamer did.

I realize that many of my audiophile colleagues are Roon fans, and I hear that works pretty well via the DAC or at least it’s getting better, and PS Audio says the PMG 512 will soon be certified Roon Ready. I have no reason or desire to use Roon, though, as I’ve been quite satisfied with Qobuz and DLNA/UPnP for many years. Maybe I’m the only one.

I trust that PS Audio will eventually solve its issues with DLNA/UPnP, perhaps even by advertising that it’s not supported. In the meantime, I’ve reverted to using my trusty eleven-year-old Aries Extreme/Matrix X-SPDIF 2 so I can again concentrate on listening to music instead of fighting to listen to it. I can even feed the Aries DSF files from my server without having to convert them. Whee! And it plays DSD256 without skipping.

My life once again has a bit less friction, and the PMG Signature 512 DAC continues to deliver excellent sound.

—Chris

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