Transports Vs Computers...is one superior to the other?

[Opusover21]

Can someone try and explain why a PC should sound superior to a transport given the same DAC and why.

Maybe I’m assuming too much and actually there is no difference? Or maybe its when HD data is introduced in which case a transport falls at the fence due to incompatibility?

 

Obviously some claim the superiority of the one over the other. I personally use the Weiss DAC2 and am extremely happy with it. Would a high transport produce the same results? No idea. I’m using the Mac mini connected by Apple’s stock 0.5m firewire cable and the results go beyond any traditional digital source I’ve owned before.

 

I’ve seen a similar post of another well know hifi forum which we didn’t really get down to resolving the debate.

 

Much appreciated!

 

 

[marconi barbosa]

Not exactly contributing to answer your question...but my 2cents here

 

I am personally not willing to pay more than the price of a macbook on a transport in the foreseeable future. To my knowledge you can find better performance today with a dedicated transport, but at a price. One reason, for example, the usb implementations that are evolving...

 

My guess is that a Computer based transport has the potential to be a less costly solution, for various reasons, including that it does other stuff too. I own two stello's dac and a macbook, very happy with this for now.

 

Another point is, just a thought: I reckon physical media (like CD's, SACD's) will soon disappear, I mean, CD will be the last widespread media type, will never die, but won't be replaced....(just my view), and hi definition war will lead to a software era, the master flac type era....

 

Cheers,

Marconi

 

 

 

[HarryHWombat]

You touch on what is becoming a very heated argument! We are in the "phony war" period before the battle and the eventual and inexorable victory of "computer" based sources. One group say that computer based sources produce a listening experience equaling or surpassing CD players costing many, many thousands of pounds, Others say this is not true. Some people say that only the DAC matters and make all transports sound the same and other say this is arrant nonsense.

 

The answer you get will depend 100% on where you ask the question. Ask it here and you will get one answer - ask it in a forums where members own CD players worth many thousands of pounds and you will get another answer. Hi-Fi has always been this way because the experience is ultimately personal.

 

The job of a transport is to extract all the bits stored on a piece of media and deliver them to the DAC, in order and in the correct timing. It is this last bit that allows people space for argumentation. There should be no discussion that a computer can read bits from media and send them somewhere else 100% correct and in the right order - this is commonly called bit-perfect - if it couldn't the world would end immediately - seriously, it would. Probably in a huge bang!

 

The space for arguments comes in the timing of the bits, whether a spreading or contraction of the wave representing a "1" has material effect on the eventual quality of the sound produced and/or whether a DAC can correct these timing errors. This is called jitter and is something I have been trying to understand and this is where the arguments can occur.

 

I do not believe that a computer should sound superior to a correctly set up transport - I do believe that it should sound better than an equivalently priced transport. If you ask the question in this way I think you may start to find more agreement. I think the reason for this is that reading and transporting bits is fundamental to every computer - it is a solved problem and is now subject to economies of scale (apple, for example, with only somewhere around 5% of the market sell many more computers than probably every single high-end CDP manufacturer put together).

 

So if you want to ask a less controversial question include "equivalently priced" and see what comes back!

 

[shenzi]

I think Harry nails it with economies of scale.

 

A computer/transport punches well above its weight in cost terms. There's also an argument that computer manufacturers have a better idea of extracting data from the disk. Where the audio manufacturers score may be the surrounding technology, how it hooks up to the rest of the system, keeping EMF and the like out of the chain. And a high end transport looks a lot groovier than most computers when placed in the living room (with the obvious exception).

 

The next couple of years are going to be interesting as the two come together. Watch out for the lazy manufacturers as they repackage computer components and charge a premium.

 

[HarryHWombat]

Shenzi --

 

Already happening!

 

[ldolse]

While the quality of a computer based transport and a high end cd transport may be arguable, I think there are a couple points that can't be argued. Jitter aside, a properly configured computer will get the bits right 100% of the time, every time. A CD tranport's success at that is highly dependent on the quality of the CD itself. An absolutely pristine CD will very probably deliver the same bits every time, but even that can't be guaranteed. As the CD is used and inevitably worn this becomes less likely.

 

The redbook format intentionally reduced error correction in the data structures in favor of increasing the amount of audio that can be stored on a CD. This can be proved quite easily by ripping a full 80 minute audio CD to a computer. This will produce 800 megs of data, only 700 megs of which can be put back as a data CD. That reduction in 100 megs of error correction data was then offset by designing a considerable amount of error interpolation into the playback routines so errors can be skipped without any obvious audible hiccups. This is all a non-issue with computer based audio.

 

Computer based audio also allows a user to easily step beyond 24bit/44khz into higher rez formats.

 

On a slightly more debatable point, I believe that a spinning silver CD platter is less than ideal as a jitter free source. There are many more options to substantially reduce jitter using a computer transport, and I think we're just beginning to see the fruits of efforts in that department.

 

[firefly0071]

For every war, there is a beginning..

 

I am actually referring to the CD players versus digital sources debate.

 

I am sure that digital sources will win (ipods, music servers etc).

 

However there will be a need for amps and speakers and hence I am not about to throw out my high end amps and speakers just yet.

 

 

 

 

 

[Opusover21]

Thanks for the comments...yes a bit of a tricky one this..but if you were to put in lay mans terms...a computer sounds better than a transport because....? I certainly dont know the answer i'm just glad that I've improved my home system and the sound it produces by instaling a Mac mini and Weiss DAC2...and probably saved a bunch of cash not to mention incorporating the ipod touch...but why does it sound better than my well regarded £3k player..cant answer that.

 

[firefly0071]

I don't necessarily think that a PC setup is better than a CD player based set up for anything under £1,500 if you made a wise choice of what you want to buy.

 

An Arcam Solo is likely to beat an equivalent costed PC music server (to use a UK manufacturer example)

 

However high end CD players are very good but not "value for money" for the additional increment.

 

For an audiophile cost is not the only issue.

 

Shanling CD players, for example, from China and upteen new tube players are very good value.

 

Ultimately it's all in the sound quality...

 

[Opusover21]

Thats food for thought..my experience has been a challenge..I'm happy with my Speakers and amps but the Digital front end was always a bit of a mystery. I've had a few players from Resolution Audio, Esoteric dCS to name a few..for the money I think computer audio is very well balanced...also the sound I am getting now is can compare at least...if my memory serves me correctly with the mentioned models. I am convinced that for example 96/24bit music etc goes beyond a conventional player. My thought are still in terms of the signal provided producing the 1's & 0's whats on what basis is one better than other...the lack of mechanics? error correction on the fly?

 

[HarryHWombat]

I am no expert but I am sure hard-disks are very much faster than CDs in retrieving and therefore transferring data. The best speed I could find in quick google was 3.6MB per second for CD and for hard disk the worst was about 40MB per second. So best against worst shows hard disks ten times faster.

 

If they are ten times faster they theoretically (again not a hardware expert, don't know how these things work) have that much more time to correct any errors in the read process. They could read the same data ten times more than a CD could before it had to be shipped out to the DAC.

 

Maybe someone with more knowledge than me can confirm or deny the theory.

 

[Wavelength]

Gang,

 

This is actually really easy. Transports read the data like it was originally intended. They cannot go back and re-read errored tracks instead they rely on error correction formula's to do this. The transport changes the speed of SPDIF to assure that the buffer going to the dac is full and that the buffer does not overrun or underrun thereby causes clicks and snaps.

 

There are a few transports such as Resolution and Ayre and I am sure others that read the CD like a computer does via ATAPI interface. Basically on the computer the stuff is read like it reads any disk with tracks. If there is an error it can re-read the track until it is correct. Though transports still cannot do this as there is no time for error recovery like this.

 

A computer has vast resources at it's disposal and can therefore be programmed to work in many ways that are far superior to a transport. A computer is not limitied by SPDIF alone it has many other means of outputing audio data.

 

But the biggest reason a computer is better is you listen to more music. #1 thing people tell me is they listen to more and different music than they ever did when they were banging cd's around.

 

Thanks

Gordon

 

[audiozorro]

Gordon well said. I am listening to more and different music than ever before. My music server is playing music at home 24/7. From the time I wake up to the time I go to bed music is playing and I generally hear something different or something I haven't heard in a while and because it's my music server it is always some music that I like. With the budget Audioengine 2 powered speakers I never think it a problem to play music continuously, though I do turn the speakers off when I’m watching TV or a movie.

 

For me this is great and there is so much good music out there, which should be good for the music industry. Nothing could be easier except perhaps for listening to FM radio at work.

 

 

[Opusover21]

Gordon I think you have some good points.. i am listening to more music..more variety...thing is most of it i listen to for 5 minutes at a time! that i pod touch makes you trigger happy...tongue in cheek i've only had it for 2 weeks so i'm sure thing swill settle down..certainly looking to grow my collection rapidly though..!

 

[tfarney]

"But the biggest reason a computer is better is you listen to more music. #1 thing people tell me is they listen to more and different music than they ever did when they were banging cd's around."

 

Yep. Organization and access. Even though I had all my CDs in binders, arranged categorically/alphabetically, which was much easier than jewelboxes on shelves, it didn't compare to the intuitive little database I have now. I find myself listening to stuff I haven't listened to in years.

 

Then there is internet radio. The drop-outs in streaming bug me, but the access is incredible. Pandora is a genius!

 

Tim

 

 

[Ashley James]

The first point I'd make is that CD player Laser mechs are very much less reliable than Computer HDs now and I've been told it's because they have to operate so slowly as they traverse the disc, that they quickly become sticky and don't read properly. We were certainly very glad to have stopped making them two years ago.

 

Vary simply explained, a CD transport is an old read mech that operates in real time. There is only one pass and if it doesn't get a read, it first guesses and then mutes until it does. This is for such a short time that you don't know it's happening (or do you?). This gets worse as the laser weakens and eventually skipping or mistracking occurs. If you import your CD to your computer with error correction on, it takes a careful read and stores the result. From then on you hear exactly the same every time because the HD is read and the information transferred to the RAM where a checksum is done. If it's correct the music plays and if not it doesn't. I hope I've got this right and that it's clear that a computer HD is a better bet. However I doubt you'd hear a difference, but if you consider these points and that most music, since the early nineties, has been at least in part made on a computer, it makes sense to use one.

 

As an experiment I'm using my Macbook Pro with an M-Audio Transit as a DAC and the results are astonishing. It's a superb and £50. I recommend buying one as a reference. If you're thinking of an expensive hi end DAC you can use this for comparison. It's a useful reference IMO.

 

Ash

 

[Opusover21]

Thanks Ashley for your input..to be honest the explanation of real time read and stored error corrected makes sense. Although how much difference to the sound it makes? does your point about if it plays it plays apply to both transport and PC?

 

[Lizard_King]

Be sure to set one up properly, use the right USB cable, power conditioner, etc.

 

[audioengr]

There are no particular advantages to either Transport method, except for those methods that are network-based.

 

In fact, the chips and implementation of either can make or break it.

 

Networked audio streaming has the MAJOR advantage that it is truly packet-based, with retry and flow-control built-in. There is no "audio stack" involved in networked streaming as with USB or Firewire. It is bit-perfect by definition.

 

As for the jitter of the various Transport solutions, disk and computer, this can vary widely. Some chips and implementations are better than others. The networked case allows for the best possible result using the simplest hardware, so it gets my vote. I'm taking about devices like Sonos and Squeezebox. The problem with these current devices is that they are not implemented like other high-end audio devices, so the jitter is higher than most high-end CD transports. This is just implementation though, and can be fixed.

 

Steve N.

Empirical Audio

 

[Ashley James]

Steve

 

People buy Sonos for its superb user interface, its very robust wireless network performance and they use the digital output if they want high sound quality. if they do this then the DAC it's connected to will re-clock or whatever. The UK Importers are good friends and they sell loads of our speakers with them.

 

We eliminate jitter completely by using SRC as do other Pro Audio and hi fi companies like Benchmark, but as Dr Chris Smith, Head of Research at Roke Manor (a division of Siemens) recently pointed out, I think on CA, jitter is dealt with very effectively in a number of different ways these days by DAC manufacturers. He'd modelled the Wolfson digital receiver and WM8741, as recently announced and showed no significant issues. This seems to be the trend, so in our opinion, jitter is no longer the worry that it was a few years ago.

 

Ash

 

[HarryHWombat]

Networked audio streaming has the MAJOR advantage that it is truly packet-based, with retry and flow-control built-in. There is no "audio stack" involved in networked streaming as with USB or Firewire. It is bit-perfect by definition.

 

Steve, you will need to explain this a little bit more! The data goes disk -> computer -> network -> wherever. The network being bit-perfect matters not a jot if the (disk -> computer) is not bit-perfect.

 

Are you saying that Firewire or USB are not bit perfect? This is not true as we would then have to throw out all out external drives.

 

I must have misunderstood what you meant.

 

[1975DCS]

In favour of the CD I do have to write that a lot of people compare CD-players out of the earlier generations, which are now equaled by average and much cheaper CD-players... I do believe that currently the new Accuphase DP-500 is the reference for a CD-player priced below the $10.000 mark. This has their new "non computer based" transport, coupled with their latest DAC series. So what if we index this at 100%, what could a computer based source do? I do have to mention that $10.000 buys you a lot of serious Audio/Computer gear...

 

In favour of the HDD based system will always be the massive collection at the touch of a bottom. This HDD based systems does however seems to reach Audiophiles only in the underground scene, well at least here in Holland! There is not a single store here selling serious USB/SPDIF converter, modified Squeezeboxes or Sonos's. The only thing I saw was a overpriced Hifidelio, modified by van Medevoort as an option.

 

Personally I only have some experience with an USB/SPDIF converter which is send back to Hawaii 4 weeks ago (but still hasn't arrived BTW), because I had occasional/several pops/clicks/dropouts with my Toshiba Satellite laptop that I couldn't fix (Foobar2000, settings, asio4all, taskmanager priority, etc, etc). I am now saving up to €1.500 and by that time (Spring) I have to be convinced to invest in either HDD based system, but if I am not convinced, I probably end up by buying an 2nd hand Accuphase DP-55 or DP-55V as source feeding my Accuphase DAC-20... As a bonus the CDP will hold it's value better too!

 

[Al]

I just want to watch this one.

 

[cfmsp]

 

"We eliminate jitter completely by using SRC as do other Pro Audio and hi fi companies like Benchmark"

 

how does use of SRC eliminate jitter?

 

edit: never mind, Steve explained in a separate thread - upsamplers have their own clock.

 

 

clay

 

 

[Ashley James]

The important thing to remember is that the music you're playing probably started on a Hard Disc in an Apple Computer and so the CD is just a copy of a computer file. Therefore it can only be as good at best, regardless of how much you spend on a player.

 

The problem facing anyone using a computer to play his music is finding the best possible DAC. Price isn't an indicator because parts aren't terribly expensive. However this is where gadgets like the M-Audio Transit can be very useful because they are good sounding if not cutting edge. They get you started and give you something to compare with your ultimate hi end solution to make sure it's better before you part with money.

 

I know that I will annoy Windows fans, but Apple's computers are preferred by Professional users, their Music Production Software, Logic Studio 8, in the opinion of Sound On Sound magazine (probably the World leader) is the best. Their computers are high end, they are better made, more easily serviced and have better residuals than PCs and Front Row, their Media program is hard to beat. I'd urge anyone to look hard at Apple before buying a PC for home media.

 

Ash