![](https://www.hifi-advice.com/blog/wp-content/uploads/2023/02/Playback_Designs_MPS-X_MPD_6_4X3A1171_750pix.jpg)
MPS-X Description
The concept behind the MPS-X Interface is to connect digital sources such as computers, servers, network-attached storage, internet streaming services, and any other digital sources to it rather than directly to the sensitive circuits of a DAC.
In fact, the MPS-X is based on the same very high-quality Stream-X2 board that is available as an internal option for MPD-6 / MPS-6 devices of the Edelweiss series but in a standalone chassis version that is designed to provide the best possible performance.
This turns it into a full-fledged standalone Network Endpoint / Streamer compatible with streaming services such as Tidal, Qobuz, Deezer, and vTuner, as well as local storage solutions on a NAS via DLNA/UPnP, and importantly, Roon.
Any DLNA/UPnP-compatible app should work with the MPS-X but the best ones are the M-Connect Control HD app for iPad and Bubble UPnP for Android. With these apps, one can stream local library music as well as online streaming services such as Qobuz and Tidal. Alas, it seems Qobuz Connect is not supported as I did not succeed in streaming to the MPS-X directly from the Qobuz app.
Arguably the best user interface is provided by Roon which also supports both local libraries and streaming service music playback, which is then streamed to the MPS-X via Roon’s own RAAT protocol.
Isolation
The MPS-X takes a three-pronged approach to achieve ideal isolation and the best possible performance. First, it employs PLINK, a high-quality proprietary fiber optical link to carry the music signal to the DAC with full galvanic separation. Second, it makes use of proprietary PDFAS clocking technology to buffer all digital inputs to dramatically reduce any clock jitter. While all the Playback Designs products have this technology already built in, adding a second layer in the MPS-X is said to further increase the performance. Lastly, the MPS-X’s separate chassis provides physical isolation and is fitted with a high-quality linear power supply.
The MPS-X has the same sophisticated clock generator and jitter filter built in as any other Playback Designs product. So, by connecting your digital sources to the MPS-X and connecting the MPS-X via PLINK to the Playback Designs DAC, the audio signal is filtered (without altering bits), buffered, and cleaned twice. Once by the MPS-X and once by the DAC, in both cases separated by a high-quality fiber optical link, PLINK.
Connectivity
The MPS-X has the following digital inputs: USB (PCM up to 384kHz, DSD up to 11.2MHz), PLINK for all native sample rates, AES/EBU (PCM up to 192kHz, DSD via DoP), S/PDIF on Coax (PCM up to 192kHz, DSD via DoP), TOSLink (PCM up to 96kHz), and optionally, Streaming via RJ45 (Tidal, Qobuz, Deezer, vTuner, NAS, Roon). There are three digital outputs: PLINK, AES/EBU, and S/PDIF on Coax.
Stream-X2 extra info
Stream-X2 is the successor of the older Stream-IF interface that was limited to 192kHz / DSD1x, whereas Stream-X2 supports sample rates up to 384kHz for PCM and 4x for DSD.
In addition to the MPS-X Interface, the Stream-X2 option is also available for the Edelweiss series MPD-6 DAC and MPS-6 CD/SACD player/DAC, as well as for the Dream Series MPT-8 Transport and MPS-8 CD/SACD player/DAC.
The MPD-8 DAC is not able to be fitted with the internal Stream-X2 option. In that case, the Stream-X2 option must be installed into the MPT-8 Transport which should then ideally be connected to an MPD-8 using the proprietary PLINK. This will then transform the MPT-8 Transport into a universal CD/SACD/Streaming transport, capable of sending native DSD through PLINK. Alternatively, if one does not mind non-matched casing quality and colors, one can also use the MPS-X in combination with an MPD-8.
Review Context
The MPS-X was listened to in the main system that consists of the CH Precision C1.2 DAC, CH Precision L1 preamplifier, CH Precision A1.5 power amp, and Magico S1 MkII speakers. Digital sources include the Grimm MU1, Antipodes K50 Music Servers (both running Roon), the Taiko Audio Extreme music server, and the Aqua LinQ network interface. Full disclosure: to avoid a conflict of interest as I also work for Taiko Audio, I will not be writing about the Extreme Music Server.
All interlinks are Driade Flow Link Reference 808, both balanced and unbalanced. The speaker cables are the Mad Scientist Black Magic.
The core components are placed on Artesania Exoteryc racks with Carbon Fiber Linear Arms. The MU1, as well as most review components, are placed on Artesania Aire Floor Platforms (also with Carbon Fiber Linear arms) which are basically identical-sounding lower versions of the Exoteryc rack. On top of the floor platforms, I tend to use Artesania KSH2 Krion shelves so that review components can be used with their own feet, as well as a selection of after-market feet.
Listening
Starting with a Qobuz source using UPnP directly via the M-Connect app on iPad and connected via Jorma AES/EBU cable to the CH Precision C1.2 DAC, the MPS-X sounds immediately convincing. It has a direct, rhythmic, fast, pure, and impactful sound, combined with deep tonal saturation and an enveloping soundstage. Its presentation is lively, crisp, and dynamic but far from being cool or dry. I know we’re “only” talking about a Streaming Endpoint, but still, the MPS-X is reminiscent of how great analog can sound, albeit not the way that some people romanticize the medium, as warm, lush, or round. Rather, it’s like a turntable that is set up to achieve superlative transient behavior whilst still possessing seemingly endless decays.
Somehow, the sound is precise and realistic yet very far from clinical. Depending on what is played, the music can actually be beautifully liquid and organic and with a very delicate touch. There is a very gentle innate sweetness which could probably better be described as a lack of edge, but without overlaying any kind of signature sound or turning over into adding romanticism. Importantly, there is no thickness in the bass and no blur whatsoever. It’s rather crafty, actually, how the MPS-X manages to present the music in an organic, human, and engaging manner without sounding unnaturally enriched, let alone colored.
My admiration for the MPS-X grew even more when I heard the exact same Qobuz source relayed via Roon running on a Grimm MU1 server and streaming to the MPS-X. Almost in every single instance that I tried it before with other equipment, Roon sounds comparatively thickened in the bass and lower midrange, and somewhat sweet and friendly overall, compared to UPnP, MPD, or SqueezeLite. Even my CH C1.2 is not exempt from this, sounding really great with UPnP but less so when streaming to it via Roon’s RAAT protocol.
This time, with the MPS-X, I was in for a surprise! Sure, Qobuz via Roon streaming to the MPS-X still sounds slightly different than direct UPnP from the M-Connect app, but really, the differences here are so small that they’re not worth obsessing over.
The only other streaming endpoint that I heard do this trick of making Roon sound as crisp as UPnP is the Aqua LinQ. I should note that this streaming endpoint actually uses an intermediate HQPlayer server/player solution and its associated NAA format to produce a sound that in practice does indeed yield a more consistent result than the usual Roon RAAT connections. And with the ongoing Roon and Grimm updates constantly changing the sound, I sometimes use the Grimm as a server only, streaming via HQPlayer to the LinQ as a player, in an effort to mitigate these differences.
After being so impressed with the MPS-X, I switched back to the Grimm all by itself (currently running Roon 2.0, build 1211), to find that while it certainly did not sound bad, its presentation did not have the same level of crispness, directness, and overall impact, as when streaming to the MPS-X. This mirrored my experiences with the Aqua LinQ, so now I wondered, how exactly would the LinQ compare to the MPS-X?
Both endpoints manage to make both UPnP and Roon sound great. The MPS-X sure is not lacking in speed, drive, or expression, but nevertheless, the Aqua LinQ is even more immediate and direct, and with certain beat-driven music styles, that can work really well. When I reviewed the LinQ at the time, I felt that it was dead-on neutral but after some recent system changes and renewed assessments, I now think it’s fair to say that it is slightly on the dry side. Just like the MPS-X, the LinQ avoids sounding clinical. But the LinQ’s immensely articulate, very direct, and super-focused sound does make it come across as slightly sober. The MPS-X simply excels in being liquid, free-flowing, and spacious, particularly possessing more distinct layering in the depth plane.
With these two rather different presentations, each will no doubt appeal to its own audience. Given the significant price difference, though, it’s not really fair to compare these two products head-on. At its price point, I know of no other streaming endpoint that betters it. But budget allowing, there is simply no arguing the MPS-X’s superiority.
But there’s a final important point to make. Although both products work suberbly well on their own and in different-brand systems, it should also be noted that each has further potential when used with same-brand products. The LinQ benefits when used with AQLink to connect to an Aqua DAC, and the exact same goes for the MPS-X and its PLINK connection. Especially the latter will become abundantly clear in my next review when I will combine the MPS-X with the MPD-6 DAC.
Feet
Virtually all audio components are sensitive to what they are placed on. The MPS-X is no exception but I found that its 3 felt-covered feet work really well. As standard, just using its own feet and on a variety of surfaces, the MPS-X sounds just right to me and although you can indeed pull the unit’s balance in a different direction if you like, I would not insist on using aftermarket feet.
If you do want to experiment, I recommend against non-damped hard couplers such as StillPoints. I tried the Ultra SS V2 but these are simply too strong medicine for this application. On the other hand, I am not in favor of soft couplers either as they invariably affect the pacing and drive. Instead, I would recommend using hard-coupling feet that nevertheless allow a degree of freedom, such as Ansuz Darkz.
The inherent high quality of the MPS-X really deserves the best feet but I should warn that with Darkz, this can get rather expensive. As I found, the S2T Darkz provide probably the best value for money but there’s no way around it and the T2 and T2S simply provide an even more realistic delivery. But don’t worry if the budget does not stretch that far as the MPS-X already sounds fantastic just as it is, using its own feet.
Power Cables
The MPS-X’s well-balanced and very neutral delivery allows it to be paired successfully with a very wide range of power cables. I found that it works superbly well even with a rather simple Belden 19364 power cable (with Bals schuko and Oyaide C-004 IEC). The GigaWatt PowerSync ULTRA also worked well, providing a smoother and richer, more liquid and more relaxed, yet still very neutral sound. But for my taste and in my system, I was most impressed with the sound when using a tight and fast-sounding GigaWatt LC-2 EVO, which I also use for the C1.2 DAC and the Aqua LinQ. In any event, the MPS-X is clearly not fussy about power cables.
Conclusion
Neutral, fast, lively, and expressive, yet finely nuanced, fluid, spacious, and gently svelte, the MPS-X offers the very best streaming audio performance that I have experienced so far. More importantly, it offers the same superb sound quality whether streaming from UPnP or using local or streaming Roon RAAT sources. The MPS-X significantly improves the sound of the two resident Music Servers whilst offering even more potential in the context of a Playback Designs system.
Stay tuned as I dive deeper into the proprietary PLINK connection and will assess what the MPS-X can bring in addition to the Playback Designs MPD-6 DAC, in my next review.
Try out Roon for yourself
External Links
Manufacturer: Playback Designs
PRESTIGE AUDIO DIFFUSION
Distributor for France & Monaco / Belgium / Switzerland
Contact : Marc Loubeau
Tel : +33(0)6 49 89 68 88
Email : contact@prestigeaudio-diffusion.fr
Two portfolios :
Prestige Audio Diffusion : www.prestigeaudio-diffusion.fr
Prestige Audio Selection : www.prestigeaudio-selection.fr
More About Playback Designs
Interview with Andreas Kock about the future of CD and SACD (feverSound.com)
Nice review Christiaan, one that digital HiEnd people was waiting for…
Thank you so much with the hope the Grimm’s will read with carefulness, in a special manner now that the “MU 2” is coming… 😉
Hi Christiaan, very interesting review. I’m wondering, since this is the best streamer you have heard, is there a reason it did not earn higher “awards” as the Grimm MU1 and Antipodes K50 both have? Not that “Highly Recommended” is not a great achievement!
Likewise, given the various updates to the MU1 and K50, has your view of these products at all diminished given the changes in sound? This must be a tricky category to review with the constant changes to hardware, firmware, Roon, etc, with your reviews being a point in time.
I have a MU1 on the way. Hoping Grimm will release their own proprietary player software at some point, like other companies have. They always seem to sound better because they have total control.
Good question:-) There is no intermediate step between Highly Recommended and Magnificent Masterpiece. Whether or not I award the latter is a bit of a subjective matter. I’ve only handed out, well, a handful so far, as I do not want to risk awarding this ultimate award only for a better product to come along shortly thereafter. Awards aside, the MPS-X is indeed the best streamer I’ve heard so far.
Indeed, streaming is under continuous development and it’s going at a rather fast pace! As for the MU1 updates, yes, they changed it considerably, as do the continuous Roon updates, and I have been addressing those in the MU-1 review as well as in various reviews of other equipment. In general, I normally don’t update reviews after the fact but I will sometimes issue a follow-up review, for instance when I gain new insights as I did for the K50 and the Aqua La Diva M2.
A major benefit of having proprietary server/player software is that one is not (or at least less) dependent on updates from a third party. This can result in better sound and potentially has a desirably side-effect of the software being very stable. That said, I don’t know if Grimm will actually write their own software or if they will simply add existing software such as MPD or Squeeze. I guess time will tell!
Is the MPS-X Using Hqplayer as the player/renderer built in? if so I wonder if it is possible to run convolution filters via the MPS-X. interesting roon sounds so good. I’ve been using mconnect for a year now and I LOATH it but can’t bring myself to use roon because of the degradation of SQ through my streamers. I’ve been considering Aurender or innuos for the reason that their software is supposed to sound better then roon with better features then mconnect.
There’s no HQP in the MPS-X. If so, then I would also have had to use HQP server on the MU-1 and select this as the output/Zone in Roon and that was not the case. It works straight out of standard Roon. Also, HQP gives a slight delay and there’s none of that with the MPS-X. But I understand your concern about Roon’s sound quality and Mconnect operation and choosing not to use Roon and looking elsewhere. I have no experience with Innuos but please keep in mind that other servers than Roon such as Aurender have their own characteristic sound presentation which you may or may not like.
Playback Designs following the principle of the Digital Director of MSB. Nice!
I’m not sure if either was following the other. It seems that the two systems were both originally released in late 2022. But do correct me if I’m wrong:-)
The MSB Digital Director was presented in May, at Munich. My point is that, both, defend the benefit of isolate the electric inputs from the DAC and keep the computing tasks outside of it.
Christiaan, Excellent review. I See the part you tested the Grimm server streaming Roon over the network to the MPS-X but Did you try playing Roon Direct through the Grimm FPGA Upsampled via AES/EBU to the MPS-X? If so what were your Findings? Thank you.
Hi Rich, alas, I did not testing using the Grimm FPGA Upsampling.
Enjoyed reading the thoughtful review. I have this unit and previously had the Grimm…I share your preference for the Playback product (as much as I like the Grimm). One correction however — the “Plink” is NOT 100% compatible with Nagra Link…I think either Nagra or PD need to make some tweaks to ensure perfect compatibility. On certain sample rates, there is skipping/glitching, using that connection.
But in any event, the Playback sings even when not using PLINK. With a reference level AES cable, I couldn’t tell much of a difference between AES and PLINK (that said, I’m obviously not using a Playback DAC).
Regarding the K50 going into your MPS-X via AES (I just noticed the K41) NOT having the AES output to player… so do you think when you are connecting K50 to MPS-X that you are actually only using the
MPS-X as a “noise cleaner” only by using the PLINK connection to DAC?
I have picked up the MPS-X based off your findings so that is a LOT of respect.
Looking forward to experimenting myself with my K50/MPS-X/MPD8 myself.
Hi Franklin, it’s great to hear my review has inspired you to get an MPS-X:-) When using an AES/EBU input of the MPX and outputting via AES/EBU to the DAC, you are using the MPS-X’s reclocking and de-jittering and potentially also benefitting from other aspects of its design. When using PLINK to the DAC, you are doing that in addition to using the optical format’s advantages versus copper cables. And we can assume that two Playback Design components may work best when connected via their proprietary format.
Mpsx works better than aurender N30sa ?
Have not compared the two but I would say too many variables to say.