Off-the-pedg PC as a music server

[fredster]

I see a lot of Mac users on this site using standard Apple computers as servers. Are there any PCs that offer the same kind of clean, RFI free output straight out of the box or would I have to build one myself ? It is my plan to go ASYNC USB DAC so I feel that in theory I should just be able to buy a PC, J River a DAC and off I go. Is life not that simple ! ? !

 

[SeeHear]

Yes, that should be all the hardware you need to go USB. Don't forget, your playback software is equally important.

 

However, if the machine's mobo has a decent digital output you might try using the coaxial output. I build my own machines, mostly from Asus mobos and have had really good results using the Realtek HD coaxial s/pdif out, especially when running Foobar under Win7. Even iTunes on XP sounds ok (with iTunes' volume maxed, appropriately sourced ALAC files activate the HDCD indicator - my unscientifc bit-perfect test)...

 

I've noticed that there is almost no chatter here about using s/pdif output, only USB. I have not had as good results using the one USB DAC I tried, the Music Hall. Using the coaxial s/pdif into my (really old) Adcom GDA-700 sounds much better than I ever got the Music Hall to sound! FYI, the coaxial output from a Creative Audigy 2 was really not good; the Creative's analog outs sounded better than using the digital. I'm guessing that's because the creative card re-samples everything.

 

I'm listening to the the HDCD reissue of Joni's Mingus album now. Decoded by the GDA-700, it really sounds good through my Sennheiser 650s :^)

 

James

 

 

[Audio_ELF]

The results with USB connected DACs vary very much depending on what the implementation of USB is. A large proportion of USB DACs utilise a basic TI (or similar) chip to provide a basic USB input - this is usually limited to 16/44.1 and 48kHz.

 

The next step up is to implement some higher level code such as the CEntrance code used by (amongst others) Benchmark and Bel Canto. This will support up to 24/96 but is still utilising adaptive USB mode where the clock is provided by the computer / USB interface.

 

The best USB link utilises asynchronous USB mode. In this method, the clock controlling the DAC is used to also control the transfer of data across the USB link. This can either be implemented within the standard USB protocols (e.g. as implemented by (amongst others) dCS / Arcam; Wavelength / Ayre and Audiolab) or the designer may choose to implement their own protocols (e.g. M2Tech, Wyred4Sound, etc).

 

With the first two methods, it's entirely possible that a SPDIF link via Co-ax or TOSLink/Optical would actually give an improvement. With async USB this should (at least in theory) be better than any SPDIF connection. Having said that, not all SPDIF outputs are created equal: if using the motherboard connection then the clock for this has to be synthesised which is not a very accurate method of clock creation, much better is to use a sound card with a real clock onboard - popular examples of such sound cards are ESI Juli@; M-Audio Audiophile 96 and 192; RME's HDSP(e) ranges and Lynx.

 

Eloise

 

[fredster]

I have been looking at the ASUS Atom 330 AT310nt-1 and the deluxe version mobos, being mini and fanless they seem ideal for building a music server. I do wonder if the deluxe would actually be a worse choice since it probably just adds potential RFI and circuitry I dont need. They both have SPDIF out according to the spec but I must say I cant see the SPDIF on the photo of the non deluxe model, but then I would expect to have to add a better soundcard for SPDIF playback anyway. Having done a lot of reading I fancy trying an async USB DAC and hopefully the signal from this mobo will be clean enough not to need to add a soundcard. If I dont get on with USB I can always add a soundcard and try SPDIF as an alternative later on.

 

My plan is to go Win7 and J River.

 

Ive found a Fortron Fanless PSU which seems ideal or maybe I can find a brick type PSU powerful enough to run the server since it shouldn't be drawing too much power.

 

I can get 4GB of RAM on that mobo so that just leaves me to sort out how I control things. With HDMI out I can use my TV and a USB keyboard & mouse for ripping from an external optical drive or downloading via ethernet, and it looks like xpTunes should give me several options for an iTouch or PDA type touchscreen control for playback.

 

That just leaves storage space, this machine will not be in the same room as my listening room so I dont have to worry about noise too much. Should I go internal hard drives or NAS ? Am I right in thinking NAS will give a cleaner output since it mean less going on within the mobo element and will reduce RFI ? If it makes no difference then internal drives are cheaper.

 

So what have I missed out ?

 

 

[fredster]

It is my plan to try a Wavelength since the ASYNC concept makes a lot of sense to me. Plus the sound seems laid back, and vinyl-like without the fatigue of some DACs.

 

If I dont get on with this then yes I would look to try SPDIF via an added soundcard of the type you suggest.

 

 

 

[ItemAudio]

There are now some specialised audio computers coming onto the market, and most of the bits you need to build a similar machine yourself are readily available.

 

By far the best sounding off-the-shelf machine I've heard or used was the Dell Mini 9. The poverty-spec version came with Linux and a little solid state drive: it was fantastic! Sadly, Dell hurriedly brushed thir underpowered embarrassment under the carpet within a few months. Great buy used on eBay, though: superb via USB.

 

[Audio_ELF]

And of course the face that you produce your own "specialised audio computers" commercially has nothing to do with the fact that you suggest one of these is better an off the shelf computer!

 

Sorry I wasn't going to mention your commercial interests which in other places were pushing the boundaries ... but this seams to clearly cross them!

 

Eloise

 

[ItemAudio]

I've always argued strongly against powerful computers for audio playback: Atom motherboards are ideal. It's quite a turnaround in mindset from the conventional IT thinking.

 

For music, low consumption and energy efficiency are crucial. The greater the voltage demand, the greater the problems with galvanic noise. In this case, less is more.

 

It's also helpful to think about shielding and vibration, and if at all possible to do without evil wireless transmitters anywhere near the motherboard!

 

[ItemAudio]

I said: “Most of the bits you need to build a similar machine are readily available.”

 

And of course the face [fact?] that you produce your own "specialised audio computers" commercially has nothing to do with the fact that you suggest one of these is better an off the shelf computer!

 

I suggested nothing remotely like that. I said nothing about anything I make or sell. In fact, I'm encouraging the OP to build something excellent himself.

 

He already recognises that off-the-shelf machines are badly designed for audio: the Dell 9 only sounded good by accident. The ingredients for a better sounding PC are available on the shelf: if you choose them wisely, and are guided by sound principles, there's no need to buy a specialised audio computer at all.

 

There's a slew of such products coming onto the market, just like tablet PCs: check any hi-fi magazine.

 

[fredster]

I guess it wont be too long before the mainstream producers catch on and start making lean, mean music machines at low cost, but for now I am happy to have a crack at building one myself. Partly for the experience of it and partly to give me the flexibility to change things as the world of computer music changes and develops.

 

Would you suggest any changes / improvements to the spec i set out earlier ? Should I be going NAS for the disk storage or is that unimportant and costly ?

 

Sorry Ive started a row by the way !

 

 

[I. G.]

"Are there any PCs that offer the same kind of clean, RFI free output straight out of the box or would I have to build one myself ?"

 

Why do you think that Apple computers offer "clean RFI free output straight out of the box" ?

 

[Audio_ELF]

Why do you think that Apple computers offer "clean RFI free output" straight out of the box?

Good point I.G.

 

They make good music servers, but nothing fundamentally makes them better than an off the shelf PC - except for physically quiet operation and running Mac OSX.

 

Eloise

 

[fredster]

The problem is I dont want Apple.

 

[Audio_ELF]

Not wanting to use Apple is fine. I think I.G.'s point is that there is nothing fundamentally special about a MacMini which makes it low RFI - yet it's still a good music server (if you want to go that route).

 

Used with a USB DAC, there is nothing special about the devices people sell as "audiophile computers". As Chris (site owner) has demonstrated before you can either build something yourself, or use an off the shelf computer to be your music server. I'm not sure how Chris feels it compares now, but he did write an article about adapting a cheep Dell for computer audio use...

 

The difficulty with off the shelf computers tends to be they are physically noisy with multiple fans. It tends to be (IME) cheeper and easier to build something from the ground up to be quiet than adapt something later. If you can keep the computer away from listening room this doesn't always matter. The other possible issue is that you could adapt the PSU to be cleaner / more audiophile based - how much this affects the sound quality is open to debate.

 

At the end of the day, put it this way - if an old PowerMac G5 is the best Apple computer for sound quality (which some people claim) then a Dell PC isn't going to have any more RFI bouncing around than that. This is on technical / abstract thinking - I've not seen anyone (independently) doing testing on this...

 

Eloise

 

PS. found another reference on building "audiophile" computer...

http://www.genesisloudspeakers.com/newsletter/Newsletter_RMAF2010.pdf

 

[Audio_ELF]

Sorry "ItemAudio" but (to me anyway) you implied if not actually stated it...

 

The question asked was...

Are there any PCs that offer the same kind of clean, RFI free output straight out of the box or would I have to build one myself?

 

Your first reply was...

There are now some specialised audio computers coming onto the market, and most of the bits you need to build a similar machine yourself are readily available.

 

Therefore (to my reading) you are saying (using different words):

No, you can't just get an off the shelf computer (though you did then mention a Dell which is no longer available); you need to buy a specialist computer of build it yourself.

 

That is just like Gordon coming on and in reply to the question How should I connect my DAC to the computer saying Oh you need a USB DAC. While the answer is not wrong by stating a USB DAC is needed he is promoting the kind of devices his company manufacturers / sells. (Note: I'm not suggestion Gordon does this).

 

No the other hand, I would suggest that (if RFI, etc is so important) then building a computer yourself is going to take testing multiple motherboards, cases, PSU, etc. so that is leaning in the direction of buying a pre-built "specialised" computer, or following a recipe such as Chris' C.A.P.S.

 

Eloise

 

PS. Maybe Chris would comment on if he accepts you comments are not self-promoting!

 

PPS. A challenge to Item Audio - if you are truly promoting people building their own audiophile computer and not trying to profit from posting comments on them here, then publish a list of parts that are in your DAT1 and DAT2 computers.

 

[ItemAudio]

Point taken.

 

It would be like someone asking: Is a computer a good idea for music? And someone from DELL comes along to the COMPUTER audiophile forum and says: “YES. And computers can be purchased READY-MADE.”

 

How grateful we should be to the vigilantes that stamped out THAT kind of nonsense!

 

Few computers sound right off-the shelf. For best results, buy or make an audio-specialised one: let's talk about how to make one. What's the problem?

 

If Gordon freely published detailed instructions on building USB DACs, would anyone be offended? If he said: “don't worry: anyone can do it: you just need this parts list and this recipe” would he be accused of anything worse than commercial suicide?

 

You appear to be promoting Apple and Genesis Loudspeakers: can you declare whether you are a shareholder in either company?

 

[ItemAudio]

1. Address galvanic noise

Start with a low-ripple power supply. Make the system as energy-efficient as possible (for instance, DDR3 memory, no extraneous peripherals, Atom CPU, passive cooling, no wireless). Avoid any direct mechanical connection to cheap switch-mode power supplies: that includes the ring main and any other devices in the system connected by conductive cabling, including the monitor.

 

2. Address mechanical noise

Avoid hard drives. Think about case dampening and isolation feet. Use an external optical drive.

 

3. Address EM and RF interference

Shield all internal drives and cables. Use wide-spectrum absorption materials near the motherboard and all components with regulators.

 

4. Address jitter

Think carefully about your choice of soundcard and cabling. Try to keep your audio signal path uninterrupted by other services: for instance, if your DAC is USB (not that I'm specifically recommending or proscribing USB as a protocol), try to avoid using USB for anything else. Investigate reclocking and buffering devices that isolate the computer transport from the DAC.

 

5. Get the software right

Audition player software. Disable all unnecessary processes and services. Ensure you have bit-perfect output.

 

There is no 'one size fits all' approach: you will probably need to tweak your computer transport (including the soundcard) to best match your DAC, which will likely favour one input if it has several.

 

Everything you need to address in broad principle is available off-the-shelf. If you're moderately competent with computer assembly, YOU NEED NOT BUY A SPECIALISED AUDIO COMPUTER!

 

Although Apple computers are very lovely, they fail several of these benchmarks, meaning that you have to spend a lot of money on the kind of DAC that minimises transport relevance (ie, more than the Benchmark) to get an uncompromised result.

 

[fredster]

Thanks all, I've got some really good input here, much appreciated.

 

I will put up a post of my final spec and design and then later how it compares to any other PCs and servers I can borrow from family and friends.

 

 

One last question, what material makes good shielding ?

 

[The Computer Audiophile]

Item Audio - You've been banned from the site once already. Usually I don't allow people to create new usernames and continue to post. I decided to give you the benefit of the doubt.

 

I highly recommend you error on the side of caution when posting. Also, people with commercial interests who post on the site do much better by laying back and only leaving a limited number of comments. Getting into arguments with readers, whether you're right or wrong, is a tough way to win customers.

 

[Audio_ELF]

Chris...

 

I remember a long time ago you posted details of a Computer Audio server utilising an off the shelf Dell. I'm not sure if you still have it ... but can you give some indication as to the SQ from that vs. what maybe considered an audiophile computer design, your C.A.P.S.

 

Eloise

 

[ItemAudio]

PPS. A challenge to Item Audio - if you are truly promoting people building their own audiophile computer and not trying to profit from posting comments on them here, then publish a list of parts that are in your DAT1 and DAT2 computers.

 

Glad you asked. I've already done that on my own site, but I'm not permitted to post the link. In any case, they were last year's recommendations.

 

Omitting anything we make or sell, I would recommend:

 

A dual-core Atom / Ion motherboard running DDR3 (I like the Zotac Ion L-E and Asus AT5IONT)

 

80W Pico PSU

 

A 12.5V power supply (more than 13V makes the PicoPSU explode)

 

Ideally, you're looking for a high rigidity non-magnetic case with copper shielding, but the next best thing is something like the Akasa Midas case which is plenty roomy (that's important), has mounting points for ITX motherboards, is well designed for passive cooling, and has a double-layer construction that you can fill with acoustic insulation and vibration damping.

 

Stillpoints fabric is the most commonly available absorption material: it's very adhesive and available in small quantities. It's not the best for wide-spectrum performance but it's better than nothing.

 

For cable shielding, try Hellerman Tyton.

 

If you can't do without a hard drive, I like Western Digital Caviar Green: quiet and energy-efficient.

 

This week, we're also liking the speed-ramped Marvell 88SS9174 RealSSDs from Crucial.

 

Anything not on this recipe I can't mention without contravening promotional guidelines!

 

[ItemAudio]

I highly recommend you error on the side of caution when posting. Also, people with commercial interests who post on the site do much better by laying back and only leaving a limited number of comments. Getting into arguments with readers, whether you're right or wrong, is a tough way to win customers.

 

Will do. Don't know if I can avoid disagreeing with anyone, though: is that a new guideline for trade contributors?! And I'm only interested in the discussion, not winning customers.

 

[fredster]

Well I for one feel you have been above all very open and helpful.

 

[ItemAudio]

I wasn't expecting Eloise to advertise quite so strongly on my behalf! I wasn't even going to mention our transports: no point if you're capable of assembling a computer yourself.

 

What is compellingly interesting is the entirely different design approach you need to take when putting together a computer for audio. There is an IT culture of 'bigger, faster, better' that puts audiophile PC builders on the wrong track from the get-go.

 

There is a persistent view among 'experts' that because all PCs open and close spreadsheets without errors, they will all sound the same.

 

A similar mistake was commonly made in the early days of CD: there was enormous skepticism about off-board D-A converters. Eventually it sank in that analog stages were hugely differentiated. Sometime later, after many 'experts' claimed it was impossible, people realised that there were good and bad transports, too: even though they were 'just emitting noughts and ones'.

 

History repeats: but unsurprisingly, all the things that really mattered to CD transports still matter to computer transports. Although there is an inherent advantage in unspooling data from memory rather than from a spinning optical drive, a general purpose computer is a far more hostile environment than that found inside a CD transport.

 

To make a good transport, you don't just lash together a few boxes from the local IT shop: you have to think like a CD transport designer. I suspect that most readers of this forum are quite capable of doing so. The rewards are audible.

 

[fredster]

I had been planning on an Atom AT310, have you tried the 310vs510 ?