Unable to enjoy downloaded DSD/Hi-Res Audio - what do I need?

Core Machine

Roon v 1.8 (build 790)
Mac Mini (Late 2009)
GPU 2.53 GHz Intel Core 2 Duo
OSX Yosemite 10.10.5
Connected to SKY router via Ethernet through a different Netgear Gigabit Ethernet switch to the one I refer to below. It is located upstairs in a separate room to my Audio system.

Network Details

SKY Broadband and SKY Router
Netgear Gigabit Ethernet Switch connected directly from the router to distribute wired ethernet connections to the AV equipment below.

Audio Devices

Connected to Netgear Gigabit Ethernet Switch: Innuos Zen Mini, Node 2i, Sonos Port, Apple TV, Sky Q mini box.

Audio Devices:
Innuos Zen-Mini Mk3 music server/CD ripper/streamer and external LPSU power supply.
Bluesound Node 2i streamer
Denafrips Ares II DAC
Rega Elex-R Integrated amplifier
Acoustic Energy AE500 speakers with REL t7i Sub

Description of Issue

I’m very happy with the sound, especially when playing/streaming my CDs from either the Zen Mini internal drive or the Mac Mini. The system is very responsive with no lag or playback stuttering. I am currently experimenting between the internal DACs (on the ZenMini and Node 2i) and the Denafrips Ares II external DAC.

However, whether selecting the Innuos Zen Mini or Bluesound Node 2i as the Roon endpoint, I am unable to play DSD files or Hi-Res WAV files. Anything above 24bit/44kHz seems to be a major problem. I don’t have any problems with Tidal Hi-Res playback, however.

For example, I am unable to playback the DSD music I purchased as a download from Octave Records. Roon attempts to play the DSD files but fails. It starts to playback WAV files at 192kHz and 96kHz, but fails after 10 seconds or so. I have tried using both the Mac Mini and Zen Mini as the source and also the Node 2i and Zen Mini as Roon endpoints (selected Audio Output devices in the Roon Remote software? I apologise if my use of ‘Roon language’ isn’t accurate).

The error message from Roon says something like:

Audio file is loading slowly- this may indicate a performance or hardware problem

Apart from Roon, I have also tried the Bluesound BluOS app and Node 2i. The Bluesound system won’t even index/recognise the DSD download from Octave records (although it finds and copes fine with playback of the 24bit/96 or 192kHz files).

  • What am I doing wrong, or what hardware am I missing?
  • Maybe the Innuos ZenMini and/or Mac Mini aren’t powerful enough?
  • Is CPU power/RAM important for Hi-Res/DSD playback?
  • Perhaps the speed of the ethernet connection is most important and creating a bottleneck. My old Mac Mini may not have a gigabit ethernet port (it’s listed as 10/100/1000Base-T).
  • Why does the Node 2i cope with Hi-Res playback when using the BlueOS app instead of Roon?

NB. I am not using the Zen Mini as a Roon core, just as an endpoint and Music server for my media files. I have also tried putting the DSD and Hi-Res audio files on the Mac Mini. I am NOT using any DSP.

Just to make sure I understand the reproduction chain correctly:
Roon Core is running on a Mac Mini.
(Where are the DSD files stored? In the below scenario, I assume they are also on the Mac Mini)
The chain goes
Mac Mini => ethernet=> Switch => ethernet => Innuos zenmini as roon endpoint (Roon Ready)=> USB (presumably) => Denafrips ?

If this is your chain, there is no obvious reason why this should not work.
This chain also puts the least amount of load on the Innuos. I run a $120 Rasberry Pi4 (with much less powerful hardware) in the place of your innuos for my office system and I stream DSD256 to the Dac via USB without a single drop-out.

To answer some of the other questions:

  • I believe that BluOS is designed to do for the Bluesound Node what Roon does for the other hardware. BluOS is part of the closed software/hardware system that includes BlueSound, Denon and few others, none of which are Roon compatible. So, using BluOS on the Bluesound Node, the system will reproduce up to the highest resolution supported by the Bluesound (24/192). Using roon to the Bluesound, my guess is that your options become more limited (e.g. Airplay and stuff like that, which does not do Hi-Res)
    In my same office system, I use a Denon avr 1600 receiver, with a modern DAC and a network streaming option built-in, but because of its tie-in with BluOS , it would not stream hi-rez files from Roon over the LAN. I simply added the reaspberry pi4 and a USB DAC.

Having spent considerable time tinkering with my home network and playing back Hi-Res (192kHz 24bit) files on my Node 2i using the BlueOS app, I think the problem lies either with Roon running on the Old Mac Mini or my network speed (or a combination of both). It works fine on the Node 2i without using Roon. Although I don’t seem to be able to get the BluOS app/Node 2i to see the DSD files.

To the best of my knowledge, the Bluesound is incapable of reproducing DSD files (One of the reasons I didn’t buy one) in their native format.
See also here for how to play DSD/DSF files using BluOs and the Bluesound Node2i (basically the Bluesound converts the files to 24/88 FLAC):

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Thanks for your reply. Very interesting observations. I opted for Roon instead of using BluOS and the Node 2i because I was not sure of the limitations of Bluesound and the Node 2i/BluOS app. Interesting that it is limited to 24/192. I didn’t realise that. Do you know if that is also the case when it is used as a Roon endpoint?

As to your question/summary of the Roon reproduction chain, it is as follows:
Mac Mini => ethernet=> Switch => ethernet => Sky Router => Ethernet => Switch => Ethernet => Innuos zenmini as roon endpoint (Roon Ready)=> Coax (cant get USB output to work) => Denafrips OR Innuos zenmini => Analog RCA out.

I can’t understand what the problem is.


Potential issues (and I’m not network expert, just a user with a lot of battle scars):

  1. the number of ‘hops’ (switch-router-switch) may be a problem. Network traffic can get weird and trip over itself for reasons mere mortals like me (and perhaps you) struggle to understand or troubleshoot.
    As a test, hook the Innuos (as Roon endpoint) to the same switch as the Mac mini, reboot everything and see if that makes a difference.

  2. Using the Innuos analog outs will definitely not work, as the dac in the Innuos is not DSD capable either.

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I am one of those too!

Me for sure, you’re spot on there.

I was wondering about the switches too, but more so about the Sky Router being in between the two switches, Mac Mini and Zen Mini. I had fewer network problems in general with my previous broadband provider.

OK. That’s what I will try next. I will relocate the Mac Mini close to my audio equipment and hang it off the same switch temporarily.

I did not know that either! You are full of new information for me. Many thanks, really appreciated.

Here’s what I’ve figured out looking at various specs with regards to DSD playback and the theoretical capability/limitations of my equipment:

Enabling DSD playback on the Bluesound Node 2i simply converts all .DSF files creating a duplicate .FLAC file in the same location for playback. But the BluOS system and Node 2i seems to work fine with Hi-Res 24/192 files.

It seems as though the internal DAC in the Innuos Zen mini is only capable of RCA Analogue output up to 24bit/192KHz and similarly for the digital Coaxial and Optical S/PDIF outputs. Thanks to @Patrick_Van_Osta for pointing this out to me.

However, the USB 2.0 digital output from the Zen Mini supports USB Audio Class 2, DoP, Native DSD and MQA. I have an external DAC. It is a Denafrips Ares II DAC. It’s capability is listed as follows:

Denafrips Ares II DAC Specs
R-2R DAC Proprietary R2R + DSD Architecture
True balanced 24BIT R2R + 6BIT DSD (32 steps FIR Filters)
Native DSD decoding with 0.01% precision resistors
FEMTO Crystal 45.1548MHz, 49.152Mhz
DSD DSD64-DoP On All Input
DSD1024 On USB input
PCM 24bits / 44.1, 48, 88.2, 96, 176.4, 192KHz On All Input
1536kHz On USB Input

This is pretty much gobbledygook to me, but it seems to suggest it should cope with DSD playback via the USB input. However, I don’t seem to be able to find a way to make it work.

Roon attempts to play the FLAC/WAV 24/192 files via the coaxial outputs on the Zen Mini (with the aforementioned Audio file is loading slowly error), but nothing at all (even with 16/44 FLAC files) via the USB output let alone the DSD files.

To be honest, when purchasing my equipment I was not intending to play much 24/96/192 FLAC or DSD content. I just fancied experimenting to see if my system was capable of resolving an audible difference with 16/44 FLAC files. Now I’m interested to find out what you need to be able to play DSD audio.

Hi Robert,
Assuming the Innuos can output digital audio via its USB ports (which the specs indicate it does), you should be able to try the following shortened chain:

MacMini (with Roon Core and presumably the storage of the DSD files) => ethernet => switch => ethernet => Innuos => USB => denafrips

Then play various file formats (24/192, DSD, etc…) using Roon Remote and see how the signal is processed or passed through for each step. The Denafrips Dac is the most capable item in the chain and more than able of playing DSD via USB input.

Your mini is perhaps under spec for dsd playback for a start. In fact it’s under spec for running roon too.

The dsd support on the ares is under maximum capability on the Mac or Linux but a windows system might get up to DSD1024.

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I wanted to point out, that the audio always goes through the Core. So, if the music is on the Innuos which is also functioning as an endpoint, it will get sent to the core, processed and then sent back to the Innuos. This extra network traffic might cause issues, which is why, my general rule of thumb is to keep all music local to the core.

As @wizardofoz says, you probably need to start by using a better Core machine, one that’s up to snuff and satisfies minimum Roon specifications. Or resist playing DSD and/or hi-res WAV files.

Thanks for pointing this out! I think I was aware of this but never thought of the toing and froing causing a problem. Wow, this is a bit of a blow, as the Zen Mini as a CD ripper, storage and server is kind of nice and convenient. Works flawlessly with 16/44 which is most of my library.

The Zen Mini backs up copies of my music to a backup folder on my Mac Mini. I suppose I could point Roon at that folder instead, or, just remove all Hi-Res files from the Zen Mini and have them in a folder on the Mac Mini as they are always downloaded purchases anyway. Roon is pretty capable when it comes to more than one location for media storage.

I will try this, thanks.

That is good to know, thank you.

I was wondering if it was under spec for DSD playback, good to know. I’ll shorten the chain, put the DSD files on the Mac Mini and see how it fairs. I didn’t realise it was under spec for non-DSP/DSD playback. It seems to work well (very responsive and smooth) with 16/44 media and Tidal. I was glad to find a use for it. :confused:

What does this mean? Sorry :grimacing:

That’s certainly on my mind now, thanks. I just want to be sure that this is the problem before I splurge my new speaker savings on a new one unnecessarily.

Roon has published minimum specs here

Note ivy bridge was released into the Mac platforms around 2012 so anything more recent should be better than where you’re at right now.

I suggest you try running the core on a more recent Mac or pc you have available now to see if the situation improves. Also run your dsd files off of local drive not over the network.

Re windows the driver for windows can support the denafrips dacs at higher rates than the Mac/Linux drivers will support.


Thanks for your suggestions. It is beginning to dawn on me that I may need to upgrade the hardware and/or OS for Roon. My Windows machine is an old iMac of the same era as my Mac Mini and is too slow.

I was considering a new MacMini with the M1 integrated CPU. I’m sure that would work fine. However, I’m interested in your comments re: Windows and my DAC.

In your opinion, does Roon work better with Windows machines?

Hi @Robert_Borley

In your setup, what stands out is definitely the CPU of the Mac Mini. It definitely falls below our recommendations and a more powerful machine will likely help here. All audio is processed by the Core first, so being underpowered could definitely cause the issues you’re seeing.

Thanks. Along with the recommendations above, I will try placing the core on a more powerful and up to date machine. I’ll report back with my experience. Just in case someone else is experiencing similar issues trying to play DSD audio files.

Taking into consideration the audio equipment and network setup I have, apart from a new machine to run my Roon core, what do you suggest my setup should look like for DSD files, in terms of the chain for music playback (as mentioned by @Patrick_Van_Osta earlier)?

With a more powerful machine for the Roon core should something like this work for DSD playback…?
New MacMini/NUC/MiniPC => ethernet=> Switch => ethernet => Sky Router => Ethernet => Switch => Ethernet => Innuos zenmini as media file storage, file server and roon endpoint (though not Roon Tested/Ready?) => USB => Denafrips Ares II DAC => Analog RCA => Rega Amp …

When you try to play dsd files what do you see for processing speed?
If you look at my screenshot you can see I’m on the edge at 1.3x at dsd512.
That’s about bottom of acceptable processing speed although works very well for me.
Just would be another good indicator that your cpu needs an update to handle dsd.

Great point. This is what I see…

It managed to playback about 20 seconds (sounding great by the way!) before the dreaded “Audio file is loading slowly- this may indicate a performance or hardware problem” message.