Difference between digital outputs

[jupiters_palace]

Hi all,

 

I'm planning to build a music server simply because its a huge leap in convenience for accessing my music library.

 

Am considering linking the the Airport Express to a DAC (brand/model to be finalised later but heart is currently set on the Musical Fidelity DACv8) as it would give me the flexibility in positioning my music server. However, I'm very particular about the accuracy of the digital signal to the DAC.

 

Firstly, do different soundcards make a difference in the digital output signal quality (both TOSLINK & SPDIF)? I remember reading somewhere on this forum that jitter could rear its ugly head depending on the accuracy of the clock on the soundcard? If the answer is yes, and its not as simple as just streaming zeros and ones, it means I would have to very particular about the soundcard as well.

 

Secondly, does the computer's innards interfere with the digital signal?

 

Thirdly, and somewhat similar to the first question, does the TOSLINK output on the Airport Express differ in quality

from a similarly priced soundcard? I know there are many variables as many soundcards differ in quality even within the same price range. What i'm really curious is whether the Airport Express can be relied upon to match a DAC like the MF DACv8 or at least the CA Dac Magic, if not I'll rather spend the time hunting for a soundcard.

 

Appreciate the world's thoughts and expertise on this, as I obviously lack the technical understanding . Thanks!

 

[cfmsp]

 

JP,

 

I notice you still have no response. It's not becuase no one cares, but perhaps due to your questions being so wide-ranging, and therefore difficult to answer without a better understanding of your situation.

 

Let's take question number 2, for example. The answer is yes. But to say that doesn't help you much without understanding a bit about your current knowledge about such things, and the extent to which you even care to worry about it. We don't even know precisely how the computer's innards affects the sound. Some claim that it's not even possible so long as the digital bits are bit perfect upon arrival at the DAC.

 

The answer to your question as to whether there are better soundcards than an Airport Express (which is NOT technically a soundcard) is yes. But so what? Without some indication of how much you're willing to spend, and how much research you're willing to do to help make your own decision, it's hard to know where to begin to help you.

 

Let's take the Airport Express. It's a rather unique piece of gear - being a relatively expensive, but very portable/versatile, router, which also happens to stream audio from iTunes (via AirTunes), and provide wireless printer support via USB. If someone wants to play redbook CD (16k/44.1) music wirelessly, it's the best value going, in my opinion. I'm not even sure there is anything comparable unless one goes with the all-in-one wireless solutions like the Logitech devices or similar.

 

With an Airport Express, you could just plug in a Toslink DAC - like the Musical Fidelity V-DAC - and you're good to go. OTOH, there are people willing to spend thousands of dollars on DACs, who would never consider TOslink or Airport Express seriously, but would certainly recommend it to their non-audiophile friends. I know next to nothing about the Logitechs, etc., but I believe the next closest value to the AE is an Apple TV, but it costs a little over $200, twice as much as the Airport Express. The advantages, it can store AND stream music files, it uses a full-size Toslink cable (no mini-adapters or custom cables required) and it probably provides slightly better quality analog.

 

The easy recommendation to you is - buy a DAC with several inputs, such as the V-DAC, and a USB or Toslink cable, connect it to your computer's Toslink (or USB) port and listen. NO soundcards needed. It if meets your expectations, enjoy it. If you want wireless, then consider the pros and cons of the AE or ATV. Either one should work fine with a $300 DAC. For slightly more money - and with a Firewire port - you could try the Apogee Duet at $500.

 

The most important piece of advice I can give you is this: do not get sucked into the game of buying stuff becuase other people claim it sounds better. That's a never ending proposition. There is NO reason to pay for gear whose differences are more subtle than you can hear. This is a VERY common occurrence in the audiophile world as most of the differences that audiophiles pay a lot of money for are just that, subtle. To hear it reported, it's night and day. Trust me, in digital audio playback, it rarely night and day, and if it is, it's not likely the product's fault, most likely you've set something up wrong.

 

Now, go out and listen to the V-DAC and another DAC or two, and report back.

 

Hope this is helpful.

 

enjoy

clay

 

 

 

 

[souptin]

I use a couple of Airport Expresses, one of which feeds a dacmagic. In the context of the rest of my system (Cyrus integrated amp and speakers, Naim cdp) it sounds pretty good, it's certainly not a weak link.

 

I suspect that you are correct to say that using the Airport means that whatever sound quality degrading things go on inside the computer case are considerably less important, but frankly in the context of my system it's not a big issue for me. That doesn't mean it's irrelevant or for much higher end setups, just that I don't think there'd be much point in you building a computer out of gold plated circuit boards and massive power supplies. Although to finish off the line of thought, the Airport itself is crammed full of a power supply, wireless transmitter, dac, and toslink, so it has much of the same potential for sound degrading problems as a computer case.

 

One thing I have found with Airport Express streaming is that it's not easy to avoid dropouts - short moments of silence as the stream re-buffers itself or whatever, a bit like you may get from internet radio. Frustratingly, different generations of itunes and firmware can make this better or worse, without much to help the end user understand what's going on. Currently, after some fiddling with network setup, my dropouts are restricted to one or two, lasting no more than a couple of seconds, for a good two hours listening. Which doesn't bother me in the least, but when it was dropping out every minute I was seriously climbing the walls in frustration!

 

edit: I just read that back and though it sounded rather negative. It shouldn't be. In my fantasy ultimate listening room setup I don't visualise using one, but I'd still have one in every other room of my fantasy lottery winners house. If that makes any sense.

 

[Tog]

Nothing wrong with Airport Express - if you consider how much it costs its nothing short of a miracle and he sound is completely comparable with a squeezebox although to my mind a Sonos has the edge (at a cost). I often use a Macbook Pro / Cyrus Dac X streaming from my Imac's firewire connected external itunes library and unless the Oven is on full blast dropouts are few and far between. The issue over toslink has been debated in these forums endlessly and suffice to say those with bottomless pockets will recommend the use of re-clockers or asynchronous USB. The information coming out of the airport or mbp via toslink is 1s and 0s nohing wrong with it - couple it with a good dac and the rest is up to you.

 

Souptin is right - try it - enjoy our music.

 

 

yours, fully expressed, tog

 

[PeterSt]

If I may say so, there is more in your both posts than just some surface touching stuff. I mean, indeed how to answer such questions without not exactly knowing what one cares about (personally I'd climb walls with dropouts of a few seconds once per two hours, to give an example).

 

Sometimes someone comes around and asks for the best audiophile reproduction possible, via a PC. Then we'd know. But, then things like an AE should be out of the answers, and not just included because "you" don't hear a difference anyway, or are not bothered by dropouts each mintue for that matter.

 

I only want to say, like you both just did or implied : it is the most difficult to answer these questions, if you first don't know what the exact requirements are. Also, what about a first time PC user ... is he/she allowed to be stuffed with dropouts (to keep it to that easily understandable subject) ? Can the first time user use the SPDIF-out of the motherboard ? Can he use a $10 PCI card ? Should the first time user be advised about any wireless device because he/she just thinks wireless is convenient ? Or may it be better to just *not* advise wireless because it is a first time user who "obviously" won't know what to do when the dropouts are all over the place ?

 

So, my contribution to this thread is just nothing. I am 100% with Clay though that very often questions can't be answered because you don't know what the good answers for those putting the questions are.

The only thing which may really help to this, say, problem, is that those asking the questions are aware of this, and create the necessary context in advance. Of course this will result in a "and I don't want a single dropout because I won't be able to solve them !", which then incurs for answers/advises like "don't go wireless".

 

0.01c Peter

 

PS: The wireless was just an easy subject. 100 other subjects are each 100 times more complicated.

 

[jerryt]

I'm using a wireless Squeezebox Duet running into a DacMagic and am enjoying the sound immensely.

 

[cfmsp]

 

 

Dropouts vanished for me when I put the Airport Express on it;s own separate network (hanging off the 802.11N Airport Extreme) - meaning, no other users sharing the AE network.

 

Then I moved to Apple TV for wireless, again no dropouts. I do suffer the occasional dropped iTunes-AppleTV connection however.

 

clay

 

[cfmsp]

 

What OS - OS X, Windows/Vista/7 OR Linux?

 

Itunes OR some other player? iTunes recommended on Mac OS X.

 

Wireless OR wired? I assume wireless based on your OP.

 

Plug and play OR configuration guru? Assume plug and play.

 

MP3s, ripped CDs AND/OR Hi-resolution downloads?

 

Hundreds of dollars OR Thousands of dollars? We can assume hundreds for now.

 

Video integration? Only relevant if an Apple TV is under consideration.

 

Quality of your playback system - speakers, amps, etc.?

 

Technology background / interest? Assume low on background for now, what about interest?

 

Anything else you think might be important?

 

 

If most of your answers are as I've assumed, then the advice offered in the posts above is consistent with the context of your query. If, however, you're a tinkerer OR hate Apple OR want to listen to high resolution downloads, the answers would be different.

 

clay

 

 

 

 

 

 

 

[Fyper]

Hi,

I've had a MF XDAC V8 for some time and it's certainly a very decent DAC. Among other things, it has a buffer and a reclock system which reduces the possible jitter coming from the source.

You've to be aware though that it has only 3 Coax Digital inputs +1 USB input, no toslink, and I'm not sure whether AEs have digital coax outputs.

Other than this I'll say what most people are saying : the digital output of AEs are offering a very good quality. I've also tested some digital output of some motherboards which are simply impressive, and so are the Squeezebox products.

If you really want to look for superior digital output quality, you'll have first to make sure that you've also the rest of your system optimised and can actually hear that superior quality.

I'd suggest to start with, to try the relativley cheap AEs, or to connect your DAC to the S/PDIF output of you PC/Mac, or to connect it through the USB connection. You should already have very good results.

Then if you want to improve things, you'll always have the possibility to make a lot of changes at every level...

 

[iamimdoc]

What Clay said - I agree wholeheartedly, particularly his last long paragraph. Memorize it

 

My 2cents re: dropouts.

From Windows using MediaMonkey, Airport Extreme and Airport Expresses - > I have zero droputs. This using a plug in for MediaMonkey called RemoteSpeaker Output.

 

I tried Airfoil For Windows and was plagued by dropouts. I have not tried there latest iteration - accordingly, it might work better.

 

 

 

[faberryman]

I have two AEs - one in my listening room and one in my kitchen. The listening room one is wired, the kitchen one is wireless. I have never had any dropouts with the wired one, and the only time I have dropouts with the wireless one is when the microwave is on, which isn't surprising given that the AE is about three feet away from the microwave. I haven't experimented with moving it further away. Sounds like a good project this weekend. In short, fears over wireless dropouts may be overstated.

 

[rom661]

This is both on and off subject. A comment was made in an earlier post on this thread about just 0's and 1's, a comment I have heard hundreds if not thousands of time selling digital gear. In fairness the last post was not in that vein, although they were mentioned. I know that is not the case because for many years I have heard a clearly audible difference in transports and cables, particularly back when separates were first popular.

 

I have long been frustrated because I know what I hear and, although the issue seems to be 0's and 1's it is clear that something else is at play. Most would agree that "something" is jitter although until recently I would have been hard pressed to tell you more than that it concerns the timing of the arrival of those 0's and 1's at the DAC.

 

I finally decided to get off of my lazy intellectual ass and find out. (My regular ass can be lazy as well) I am now learning. I invested $40.00 in a copy of Ken Pohlmans "Principles of Digital Audio" at the urging of one of the engineering people at Sonic Solutions/Amarra. I'm not an EE. Some of it is over my head. However I understand the concepts so far and it goes a long ways towards explaining why I have heard the differences I have heard and what causes them. I highly recommend it. And I am now much better equipped to explain, both subjectively and objectively, why the 0's and 1's comment is oversimplified and misleading.

 

Thanks. And I'm sure most libraries would have it. The most recent edition also covers USB.

 

Rick

 

[peechus]

I too suffered the heartbreak of dropouts and rebuffering with airport express and extreme. Tried other wireless routers, range extenders and floobydust to no good end. Contractor to the attic, 100ft ethernet run, 200 bucks =sleep for the innocent. Novice smartted up...Peechus

 

[Audio_ELF]

Unfortunately I think you are out of luck using the Airport Express directly with the Musical Fidelity X-DAC v8 as (IIRC) the X-DAC has no TOSLink / Optical input. You could use a converter such as the M-Audio CO2.

 

Generally the X-DAC v8 is very good, though unfortunately I think it's been discontinued so only available second hand / ex-demo.

 

Eloise