Updated: 2016-10-11

History

Some time ago (say, December 2013) sources of DSD downloads that we knew about could be counted on the finger of one finger. Now (December 2014) they’re all over the Internet, a new one every few days. And some of them even sell content that is DSD along the entire chain! (Note that some SACDs use PCM source material and/or PCM processing, which rather gets in the way of the advertised benefits of Pure DSD.) 

Up until Logitech Media Server 7.7.x., making a DSD fit to play on Squeezebox involved using Foobar2000 to encapsulate the DSD in a FLAC container as a kind of Trojan Horse to move the DSD stream from the server through the player. Not so hard, but … Since March 2014, Linux server version 7.8.0 has included the plug-in ‘Play DSD Audio Files’. Now Windows and Mac servers have DSD capabiltity with version 7.9.x, using the plugin DSDPlayer. (Thanks to George M for providing this update info to us.)

At one time, consumer DSD DACs  were somewhat  rare outside the confines of an actual SACD player. Now many high-end companies like Mytek, Lampizator, Playback, Benchmark and others sell DACs with genuine bitstream converters. Note that some DACs advertised as DSD capable do exactly what Squeezebox does: they convert the DSD stream to PCM and then processes it in the normal PCM way. Caveat emptor.

Also, at one time, the only way to suck the DSD content out of a standard SACD disk was to find an ancient Sony PS3 machine, load a new operating system on it, and use an esoteric process to rip the files. The few machines that Sony issued without realizing that they had allowed this loophole out into the wild are now quite valuable. But today … well, actually that hasn’t changed. But we do have downloads. See above.

So now you can play your DSD files on Squeezebox (restricted to stereo just now). If you have a DSD DAC, then you can hear the files in the way they were intended to be heard. Even if you just have a traditional DAC then it can still play the music very nicely, providing your DAC can handle 176.6/24 files.

Finding DSD files.

(Completely optional step) You can still rip your SACDs. SACDs are just a container for DSD files, so all you need to do is pull the file out of the container. That is not as easy as it sounds, because the inventors of SACD technology had as a guiding principle that to rip an SACD should be very, very difficult. At Easysqueezebox ‘easy’ means both conceptually straightforward and not a whole lot of fuss and bother. For that reason, ripping SACDs is not something we want to spend time on. If you must, this might be a good place to start:  http://www.computeraudiophile.com/f11-software/sacd-ripping-using-your-ps3-part-2-a-7495/. In theory not so hard, but good luck finding a working version of the right variety of PS3.

Probably many of us, if we're interested in DSD at all, will prefer to simply download the DSD files. We recommend DSF files if you can get them, rather than DFF files. They both play on Squeezebox, but DSF has some tagging capability which allows Squeezebox to display the usual album and track information.  Several DSD download sites are included in the list in this Easysqueezebox article.

If you want some sample files before you commit to the enormous expenditure of buying a real DSD DAC and a drive-full of DSD downloads, then here are some sites to try:

(Optional step.) If you plan to use a DSD-capable DAC and if you want more sophisticated tagging than DSF can handle, then consider putting the DSD file into a FLAC container. Seems like a lot of work for not much payback, but then, we’re lazy.  We’ve tried a couple of Mac/Linux apps, and no doubt smarter people than us can make them work. If you want it easier, use the excellent Foobar2000 on Windows, plus the relevant plugins as described in the instructions at this location.

Once you’ve downloaded your files, transfer them to your Squeezebox server in the normal way, and rescan the library.  

Setting up the Squeezebox Server and Players on LMS 7.8.x Linux

  • Make sure you’re using Logitech Media Server 7.8.0 or later. You can download it here or as part of a Vortexbox new installation. See our other articles for installation tips. Note that the official 7.7.x version from the Logitech website does not have DSD capability.
  • In the LMS 7.8.x server web interface, go to Settings / Plug-ins and find the 'PlayDSD' plugin (7.9.x) or ‘Play DSD Audio Files’ plugin (7.8.x). Check the box to make it active. (If you can’t see it, you may need an updated version of LMS.) Click Apply.
  • You may have to restart your server for the plugin to become active.
  • In the LMS server web interface, go to Settings / Advanced and select File Types in the dropdown. The defaults are probably OK but if necessary change the file type settings as shown, and click Apply.

DFF – DFF – native
DFF – FLAC – dsdplay
DSD Audio file – FLAC -  dsdplay
DSF – DSF – native
DSF – FLAC – dsdplay
FLAC – FLAC – native
FLAC – PCM - flac

  • In the LMS server web interface, go to Settings / Player.  Use the first drop-down to select one of the players you plan to stream DSD to. Then use the other drop down to select ‘Play DSD Audio Files’.
    • PCM option: If you plan to use a PCM DAC with this player leave the check box ‘Enable DSD-over PCM’ unchecked (Squeezebox will convert DSD to PCM before sending it to the player). 
    • DSD option: If you plan to use a DSD DAC that can handle DoP (most can) then check the box ‘Enable DSD-over-PCM’ (Squeezebox will send a DoP stream to the DAC which will extract and convert the DSD content). 
    • While you're in the Settings / Player tab, use the dropdown to select 'Audio'. It is essential that the DSD bitstream does not get altered in any way by the server or the player. So configure these important settings as follows:

Crossfade: None
Volume Control: Output level is fixed at 100%
Bitrate Limiting: No Limiting
Volume Adjustment/Replay Gain: No Volume Adjustment

  • Repeat for every player you want to use for DSD playback.

Setting up the Squeezebox Server and Players on LMS 7.9.x Linux, Windows, Mac

  • Windows and Mac users have to update to 7.9.x. to play DSD files directly.
  • In 7.9.x use the plugin 'DSDPlay'. In the LMS 7.9.x server web interface, go to Settings / Plug-ins and find the 'PlayDSD' plugin (7.9.x). Check the box to make it active. (If you can’t see it, you may need an updated version of LMS.) Click Apply.
  • You may have to restart your server for the plugin to become active.
  • You should find that all your players have defaulted to the correct option. For devices that cannot handle DSD files natively, the default setting should show: "DSDPlayer will transcode DSD to PCM for this player". This is exactly what you need for devices that include or output to a conventional PCM DAC. 
  • For each player, go to Settings / Player / Audio and make sure these settings for digital output are correct:

Crossfade: None
Volume Control: Output level is fixed at 100
Bitrate Limiting: No Limiting
Volume Adjustment/Replay Gain: No Volume Adjustment

  • At this point we have not tested the ability of DSDPlayer to send a DSD-over-PCM stream. 

Now enjoy your DSD-based music. We have heard DSD (but not, admittedly, via Squeezebox, yet) and it sounds good. But then, we have also heard high-definition PCM and that sounds good. Your experience will vary according to your ears, equipment, taste in music and the way your music was recorded and processed. Do your assessment and then just crank it up and enjoy the music.

Our Test Results - So Far

Work is still in progress. We have tested various devices in PCM mode (conversion from DSD to PCM) but so far we have not tested the 'native DSD' option. (We need to buy or borrow a genuine bitstream DAC.)

We tested using the sample DSF tracks from Ayre streamed from LMS 7.8.0 (Vortexbox/Fedora Linux) from LMS 7.9.0 (Vortexbox) and LMS 7.9.0 on Mac.

External DACs were PCM only: a Benchmark DAC, a Classe SSP and an Onkyo SSP. We have had successful results with:

  • Logitech Squeezebox Boom, built-in DAC
  • Logitech Squeezebox Touch, coax out to external DAC
  • Logitech Squeezebox Touch, built-in DAC
  • Squeezelite on Pi (PiCorePlayer), HDMI output to SSP 
  • Squeezelite on Pi (PiCorePlayer) built-in HiFiBerry DAC
  • Squeezelite on Pi (PiCorePlayer) built-in HiFiBerry Digi, coax digital out to SSP
  • Squeezelite on Pi (PiCorePlayer) built-in HiFiBerry Digi, coax digital out to external DAC
  • Squeezeplay software on Macbook, OS/X, optical out to external DAC
  • SB Player (Angry Goat) app on Amazon Fire, digital coax passthrough (24/48) to external DAC

Since we know that not all players can handle the highest sampling rates, we would not have been surprised to find some problems. However in every case Squeezebox successfully downsampled the PCM streams from their original rates to match the max rates available from these players.

When comparing the playback of the Ayre PCM files against the Ayre DSD files converted to PCM by Squeezebox, we heard no obvious differences, which is not really surprising. When we move on to comparing the PCM files with DSD decoded using a native DSD decoder, we might hear some difference one way or the other. (Still looking forward to doing that!)

We also tried some DFF files, which also worked. Although DFF files can play just fine, we prefer DSF because DSF can contain some basic tags, which avoids the need to enclose the file in a FLAC container just for tagging purposes. Moreover, we also see a trend in download sites moving to standardise on DSF. 

Note 1.

There are a number of DSD DACs that work by converting the DSD stream to PCM and then using a conventional PCM DAC to do the conversion. If you have a DAC like this, try it both ways: (a) deliver DSD to the DAC and let the DAC do the DSD to PCM conversion, and (b) convert to PCM in Squeezebox and use the DAC as a normal PCM DAC. Listen and choose the method that sounds better.

Note 2.

The very good people at Ayre have done a wonderful thing. They have prepared fragments of music in both DSD and WAV (PCM) formats for you to compare. They used a vinyl source so they could have complete control over the production chain, so the signal-to-noise ratio might be slightly inferior to CD quality, but the frequency range might reveal more higher order harmonics than CD would. The importance of this is that as much of the process chain as possible is common, so if any differences are discernable, you will be reasonably certain that the format has something to do with it. More details on the Ayre website. Please provide your feedback to Ayre once you have made an honest comparison!

 

Copyright, Liability, Privacy  •  Contact Us  •  Contribute