Category Archives: Music Servers

If one format is better than another, why doesn’t the music always sound better?…

So here’s the deal….  DSD recordings are the gold standard of high definition digital audio.  They are not always the best digital recording of any particular album, but they have the opportunity to be.  Just because a title is released on SACD (i.e. DSD recording) doesn’t mean that the recording engineers did everything else possible to provide the best quality.  Sound quality varies title by title, and I’ve listened to many DSD recordings and found that  some are better than others, just as I’ve found some vinyl recordings are better than others.  A perfect example of a dismal DSD formatted release is the SACD version of U2’s “Achtung Baby”.  The fault isn’t in the DSD format, but rather in the fact that the original master tapes were 16 Bit DATs (Digital Audio Tapes – The “Dark Ages” of High End Audio).  So the SACD version faithfully reproduced the totally flat (lacking dynamic range) and lifeless sound quality that the original 16 Bit DATs were limited to.  Garbage in, garbage out syndrome and, as much as the purveyors of such releases would like you to believe that upsampling performs some kind of voodoo magic, it doesn’t.  You simply can’t make chicken salad out of chick shit.

The very highest quality DSD recordings are those made “direct to DSD”, meaning that the artist’s were assembled in the studio for the purpose of “cutting” a DSD master recording.  Since “direct to DSD” recordings have only been around for less than a decade, they are limited to new and relatively unknown (though often very talented) acoustic artists.  The “direct to DSD” concept is analogous to the “Direct to Disc” recordings put out by Sheffield Labs in the 1970s, where the artists would record direct to the vinyl cutting lathe without interruption.  That’s right, at the time “disc” meant vinyl record.  Not only did the artists have to perform flawlessly for an entire record side but, perhaps an even more amazing feat, so did the recording engineer who was continuously adjusting and mixing the levels of up to 24 tracks simultaneously.  Screw it up and everyone starts over, not from the beginning of the song but from the beginning of the 20+ minute LP side.  Painstaking to say the least, but these releases eliminated one more link in the recording chain, the analog master tapes – the recording went straight to the LP cutting lathe and the recordings were used industry-wide to showcase what audiophile quality sound was all about.  In fact, Dave Gursin’s “Discovered Again” direct to disc recording was one of the reference LPs (What is a “reference recording”?) of choice for the loudspeaker designers at Audionics of Oregon when I worked there back in the late 1970s.

Second to DSD digital quality is PCM with a resolution of 24 bits, at a sampling rate of 96 kHz or 192 kHz.  I’ve found that the 24 bit depth resolution to be the key factor, and the sampling rate to be far less significant.  This makes perfect sense when you think about it – 24 bit sampling offers a resolution that is 256 times greater than the 16 bit that “Redbook” CDs offer.  Since digital is binary, we are talking about 2 to the power of 24 (16,777,216 bits) vs. 2 to the power of 16 (65,536 bits), whereas a sampling rate of 192 kHz is only 4.3537 times greater than that of 44.1 kHz.

And not all titles are available in all formats.  That’s why I’ve got a mix of different formats and have several titles in more than one format.  Interestingly, DVD-As are going way up in price since the format is dead and they are becoming more collectable.  A sealed copy of Steely Dan’s “Gaucho” on DVD-A sells for around $120 vs. $15 for a sealed SACD copy, even though the SACD release has superior sound quality.  Go figure.

Online downloads are getting better all the time and are perfect for those who prefer the convenience of having a music server.  But be careful as many tracks are just up-sampled and resold as being higher definition.  In case you are wondering what a music server is, just think of iTunes.  It is the most ubiquitous music server in existence and remains the ultimate example of convenience over quality (as for audiophile quality music servers, see DSD Music Server project).  The files sold on the iTines Music Store are grossly inferior to even Redbook CD quality (16-Bit/44.1K), and useless for high definition audio playback, though useful for other listening (What I love about MP3s).

Online downloads of high definition audio files come at a premium price.  For example, the cost for a PCM 96K/24 bit download of Eric Clapton’s “461 Ocean Boulevard” (a fantastic recording) costs $25 and the better quality DSD version on a sealed SACD costs only $16.  But listening to the SACD means you need to get  out of the listening chair and insert the SACD disc into your player whereas with the PCM 96k/24 bit file on a music server you can buy individual tracks, make playlists,  and sit on the sofa and change your mind, all iTunes style.

And… the techies love the gadgetry that the music servers offer, “Hey, check out what I can do with my iPhone remote”, and are willing to compromise quality for it.  Some will argue that is not the case but they are likely spending more time discussing it on the forums than sitting down and listening to their music.

I’m of a different cloth, where sound quality is paramount and everything in my system is selected to that end.  That isn’t to say that I won’t connect my iTunes server to my high end system and put on background music.  But when I do my “sit down and listen” sessions, I want the best quality possible.  As I write this I am listening to DSD off my music server and warming up my amps for a vinyl session.  Not many people sit down and listen to music anymore, and that’s fine.  I just happen to be amongst those who still love doing so.  Over… say, watching TV or listening to NPR any day.  I suspect few with high-end music servers sit down and listen to their music much, where they do nothing else but enjoy the music.  And that’s fine, they have some of the finest quality background music playlists the world will ever know.

Linn has been leading the charge for good quality high definition digital audio with their SACDs and music servers.  This is ironic, since they established their name based upon their venerable LP-12 turntable, which is still sold to this day for several thousand dollars.  More importantly, they are “all about the music” and go to great lengths to get the recording right in the studio.  And, when they put one of those recordings on a SACD the results are astounding.  The first time I sat down and listened to one of their reference recordings simply redefined what I considered digital audio capable of.

DSD Music Server project

As many of you know, I’ve been working on a DSD Music Server project for neigh on a year now. Still a work in progress but I just couldn’t resist making some initial comparisons and evaluations that have been a long time coming. I based my purchase decisions for music formats over six years ago based on auditions and comparisons of the formats on a high end system in a shop in Seattle, but now I finally have my own (even better) systems to compare and contrast.

First, the Canada system used for listening evaluations:
Vinyl – Pioneer PL 530 running a Denon 103R MC cartridge
SACDs – Marantz DV-7600 SACD Player
DSD Streaming – MacBook Pro into a Teac UD-301 DSD DAC
Preamp – Threshold FET 9
Power amp – Nakamichi PA-7
Speakers – Magnepan MG-12s without Attenuation
Interconnects – Zu Audio Wylde
Speaker Wires – Heavy gauge hardware store copper, terminated with banana plugs, haven’t upgraded yet (see later post where I upgraded and evaluated the results here).

Ok…  So I’m gonna avoid a lot of the B.S. and cut straight to the chase.  But first, one major caveat.  Since I have no remote control (Why audiophiles don’t get to have a remote control…).  I used the source selector switch on the preamp and therefore wasn’t in the sweet spot.  Before you say, “all bets are off then!” let me explain.  My Maggie’s like to be very far out from the rear wall in my listening room.  That, combined with the fact that they are bipolar speakers and radiate in an equal and opposite fashion back towards the octagonal bay windows (three big panes of glass) I actually discovered another sweet spot behind the speakers, where my amps are.  It’s very small and goes away if I move or tilt my head even inches, but is unmistakably there 🙂

So here are the results of the A/B/C tests (yes, I went to the trouble to sync all three sources and even volume match DSD DAC to SACD Player).

Vinyl – dramatically different, another flavour entirely. This is the first time I’m not going to call it “better” just “different”.  That’s how good my DSD has become.  So the vinyl has a rich, warm, full bodied sound.  My Maggie’s aren’t big in the bass department but I also know from my Maui Kefs (best bass I’ve ever heard) that that is another area where vinyl kicks ass. The high frequency response doesn’t seem as crystal clear as SACDs or DSD DAC, but I’m wondering if that is because it’s less pronounced due to the full dynamic range that vinyl offers.  TBD…  Will need to do more listening and will need to be in the sweet spot, the one in front of the speakers, to evaluate further.

SACDs – The gold standard of digital audio to be sure.  Crystal clear highs, amazing transient response, fantastic imaging. And exemplary during quiet passages due to very little noise.  Sounds just a bit thin compared to the vinyl, but now we are talking pros and cons in that regard since it sounds so amazing in other areas. Although not part of the comparison, I heard Tubular Bells like I’ve never heard it before listening to it from the DSD DAC later in the sweet spot, and that says a lot!  Of course, my Maggie’s LOVE that album, it plays into all their strong suits and I’ve only played the vinyl on my Kefs on Maui.

DSD DAC – almost indistinguishable from the SACD but I’ll give the SACD the edge, which came as a surprise to me since the DSD DAC doesn’t have any issues that come with the transport and therefore if anything should sound better. I’m not saying it sounded harsh or harsher cause neither of the sources sounded that way, they were both amazingly not so for digital (thank you DSD). What I will say is that the SACD player sounded more analogue-like.  Just a very small amount smoother and warmer.   I’m guessing that is due to the OpAmps in the output stage of my DSD DAC (Op Amps are holding back my digital quest) vs the very high quality discreet circuitry in the output stage of my Marantz SACD player. Can’t be sure without other DACs to compare of course, but that would be the logical conclusion, which I came to after doing some further investigation and finding that the DSD DAC uses OpAmps, which make sense for the price – still trying to get champagne taste on a beer budget and I’m doing really well so far!

When I sit down to listen to music, I want the best quality possible, which means DSD, 24 bit PCM and vinyl.  I had loaded up around 5,000 tracks in 44.1k/16 bit PCM (Redbook CD quality) onto my music server, thinking that I’d listen to them if that’s the only format I have them in.  But I never did.  I guess that shouldn’t be a surprise, that when I sit down and listen to music Redbook CD quality just isn’t going to be on the menu.  At first, I did lots of A/B testing of the 44.1k/16 bit albums to the same album on DSD and/or 24 bit PCM.  The results weren’t surprising, very drastic differences in sound quality.  I finally figured, “what’s the point?”, and removed the 44.1k/16 bit tracks from my music server.  Not because they were taking too much space, the inferior bit depth and sampling rate results in very small file sizes, but rather because I didn’t want them cluttering up my selection of high definition digital music with files that are sub-par.

Postscript – I later discovered that it was in fact the OpAmps in the Teac DAC that was infecting my digital music server (Op Amps are holding back my digital quest), so I replaced it with a Marantz that uses discrete circuitry (Marantz DSD DAC).

Mac Mini as a Music Server

I’m not an Apple fan.  All the less so for the limitations of OS X for handling high definition digital audio.  And trust me, if there’s a way to screw up your audio quality, iTunes will find it.  So I’m also not a fan of claimed audiophile software that uses iTunes as the user interface.  And native DSD playback isn’t possible with such iTunes-structured programs, that are PCM based.  If the volume control in iTunes changes the volume on your system, you’ve been PCMed (Why audiophiles don’t get to have a remote control…).

But the obvious and most ubiquitous choice  for a dedicated computer as a music server is a Mac Mini.  So a friend gave me a not-so-old Mac Mini and it’s now my Music Server on Maui.  And I subsequently purchased a new one for Canada.  So a few thoughts after listening to the Mac Mini’s so far…

First off processing power is virtually irrelevant to sound quality.  Anything in the last few years is plenty.  Why?…  Remember, this is a dedicated computer so you are only running your high definition audio software on it, right?  This software uses less than 10% of the processing power any relatively new Mac Mini offers.

Second, RAM could make a difference depending on your hard drives.  The most demanding requirements will be playing 5.6 MHz DSD files and 392 KHz/24 bit PCM files.  You may run into occasional buffering issues with these files, but it’s not insidious to sound quality, more glitchy in nature.  In other words, you won’t hear a sonic difference due to insufficient RAM, but if a song suddenly stops playing then catches up, you need more RAM to buffer your files.

Third, your power supply doesn’t make a hill of beans of difference to sound quality.  Sonic benefits claimed my the vendors of upgraded power supplies are borderline fraudulent.  It doesn’t require a physics degree to grasp this, but if you have one you will immediately realize that the vendors selling upgraded power supplies for the Mac Mini to improve sound quality are claiming to defy the most basic laws of physics.  I’m all about high quality power supplies in amplification circuits, but EMI (electromagnetic induction) simply doesn’t effect the sound quality of digital circuitry.  If it’s “bit-perfect” than the job is done and it ends there.  And all the Mac Mini is responsible for is digital file delivery… you’ve got an external DAC, right?

Fourth, hard drives can make a difference, especially for music with soft passages.  Go fan-less!  (What are the best external hard drives for a music server?) Which unfortunately precludes all NAS (Network Attached Storage) devices.  I have yet to find one without a fan.  And, ethernet is a noisy, high-traffic, and relatively slow cabling solution anyway.  Noisy to the point where it can effect that “bit perfect” pass-off you’re looking for.

Which brings to mind the fifth requirement, a USB DAC.  Not toslink or digital coax, both of which are the legacy of Home Theatre audio.  And… if you have a USB DAC, you may want to keep your hard drives off the USB bus as it will already have it’s hands full if playing 5.6 MHz DSD or 392 KHz/24 bit PCM files.  So put your external drives on the Mac Mini’s Firewire 800 bus, which is latent anyway if your Mac Mini is a dedicated music server.   You could also use Thunderbolt but I see no benefit over Firewire 800 and two possible detriments, the first being high cost and the second being the possibility of having to share it with a monitor.

Speaking of monitors, the video circuitry in your Mac Mini won’t effect sound quality at all.  This is very different from an SACD player that has video circuitry in it, where the SACD player is performing the DAC (digital to analog) conversion internally and therefore has analog circuitry that can in fact be effected by video circuitry and therefore the possibility of sonic degradation exists.  Having said that, why not use screen sharing from your laptop in your listening chair and not have a video monitor hooked up at all, then you have the ultimate remote control!  (still no volume control for native DSD playback however).  Or if you’re using JRiver for your music server software you can use the very capable JRemote iPad app.

I’m not going to point any fingers here, but I will say there are a few vendors selling “upgraded” Mac Minis in excess of $10k.  Don’t go there, stick to the the basics and spend all that cash saved on good quality music!


DSD DACS… affordable at last.

23Jan2014 – “I won’t (spend $1.5k on a DSD DAC).  I guess you didn’t read through my email, where I suggested to wait for the DSD/PCM combo DACs to come down to $500 or less, which they will within a year:)  It’s highly unlikely I’ll spend more than that on a USB DAC for my digi signal path.”

Review of the UD-301 here


17Feb2014 – and, i now have nearly 100 titles of my SACDs for the time when the DSD music server becomes a reality.  i would estimate that to be at least a year away since it will take that long for DSD DACs to become main stream and hence more reasonably priced.  once again, worth the wait for the pursuant quality.  shootz, i’ve already waited over 20 years for quality music again (i.e. since the day when 44.1/16 bit CDs took over), what’s a little more?…