'Build a Better Audio Computer'

edited November 2012 in Digital
The following is from the FAQ section at Item Audio's online shop. Mark has put together a guide to self-build a computer audio transport that he puts together and sells.

This knowledge obviously has taken a while to put in writing, but that's nothing compared with the time and effort (and expense) that must have gone into gaining this experience. I like the fact he is sharing this with the wider audio community, that he puts his ideals where his mouth is and is pushing computer audio forward.

He has already posted the same thing at pfm, and it got a pretty heated response from those who can see no good motive or sound logic here. "Bits are bits, all computers are good enough", etc. However, while I cannot comment on whether this approach has merit due to my own lack of experience, it still seems a generous step to publish instructions on how to build your own audio computer, based on the Item T1 computer transport.

Hopefully the benefits of this approach will come full circle; more people will engage with a controversial subject, more people try it for themselves, knowledge increases, audio quality may increase also. Computer audio is the future, so why not smooth the way a little? Mark is definitely to be applauded for this step in my opinion, and though he may lose a few sales of built units he hopefully will make up for that in component sales as newbies have a go. Although I am still to finish modifying my Apple mini, I am very interested in following the T1 recipe next year, which has superseded the CAPS as my preference for a self build.


  • edited November 2012

    From Item's FAQ section:

    Our Second Generation recipes, dating from late 2009, proved
    extremely successful in extracting the best possible performance from
    Atom-based motherboards, culminating in the award-winning DAT1 with its
    tri-linear power supply. We remain committed to advancing the quality of
    computer audio playback, and are happy to announce our Third Generation
    recipes enabling customers to build their own versions of our 2012
    T-Series computer transports.

    So what's new? Well, the Third Generation recipes focus squarely on
    the computer as a USB device, in step with the groundswell of movement
    toward asynchronous hi-res USB DACs. For the first time, we also move
    away entirely from the low-power Atom platform: leveraging Intel's new
    32nm 500-Series Celeron processors in the Model 1 transports, and even
    lower-powered systems in the Model Zero transports. More on this, and
    the Model 2 transports later. Crucially, also we're pleased to announce
    the availability of the world's first commercially-available computer
    transport featuring full fibre-optic PCIe isolation - solving many of
    the problems arising from the plethora of noisy regulators populating
    modern motherboards. We have retained the operational cornerstones of
    the first and second gen transports: silent, upgradeable,
    tablet-operated, and only ever primary linear power. We now also have a
    recommended Linux solution that runs from a very small footprint as an
    alternative to Windows XP, which remains our OS of choice - although we
    do now recommend the combination of JPlay + Windows 8.

    The use of the Adnaco fibre-optic PCIe/USB system in particular makes
    possible the use of one machine as a high end USB transport, and a
    BluRay and HD home theatre system with up to 9Gb on-board storage. For
    the first time, the requirements of audio and video players can be
    combined without compromise.

    The advance from Atom to Celeron offers no penalty in terms of power
    consumption, but brings major improvements in processing power (see
    below) which has significnatly reduced 'software jitter' and DPC
    latency: we're now effortlessly achieving baseline figures in the 2-5
    microsecond range - even with Gigabit ethernet in play.

    Also, for the first time, we've made available all the parts needed
    to build your own T1 as a complete kit to which you can add your choice
    of case and further optimisations. The core components are are follows:


    Intel DH61DL Mini ITX motherboard: £65
    Not only
    is it one of the cheapest Mini ITX / socket 1155 boards you can buy, it
    is one of the simplest and cleanest-running: drawing less than 1.25A
    idling (including processor and RAM). The Intel SATA drivers (although
    limited to 3Gb) are very stable and do not affect latency – an issue
    that plagues many SATA6 implementations. It's USB3 port is driven by the
    Renesas chipset which has proved to be one of the best-sounding
    implementations available. The mini PCIe slot allows for the ultimate
    energy efficient and high speed startup drive (mSATA) to be installed -
    but it also has a PCIe 2.0 4x slot which is essential for the Adnaco and
    SOtM add-ins. There is a DVI digital video port for high quality
    monitor connection. Tucked away inside is an SPDIF header waiting to be
    tapped. It has a proper 24+4 pin ATX input and, perhaps most crucially
    of all, it plays nicely with dumb multi-rail linear PSUs. At the time of
    writing, we believe there is no better board for an audio build.

    Intel Celeron G550T processor: £39
    Although rated
    at 35W, in reality, this 'T' designated G550 draws no more power than a
    dual-core Atom. The closely-related G530 is currently ranked by CPU Benchmark as the second best value processor (performance v tray cost)
    currently available. Despite the previous stigma attached to the Celeron
    brand, the latest 32nm G500 series are outstanding examples of
    low-cost, high efficiency design. Basically, OOE trumps HyperThreading.
    But as well as Atom's failure to handle out-of-order execution, the
    DH61/Celeron platform offers a number of key advantages over the Atom
    architecture - even the latest and most powerful D2700:

    Bus speed - Atom: 2.5 GT/s |  Celeron: 5GT/s
    Cache - Atom: 1Mb L2 | Celeron: 2Mb SmartCache
    Memory type - Atom: single channel DDR3/1066MHz | Celeron: dual channel DDR3/1333MHz
    Memory bandwidth - Atom: 6.4GB/s | Celeron: 17GB/s
    Max memory - Atom: 4Gb | Celeron: 32Gb

    To reiterate: these benefits, specifically those targeted at improved
    memory performance (important given that chosen apps use memory
    playback) come without meaningful power or cost penalties. Despite
    Intel's conservative rating, in reality this board/processor pairing
    draws no more current than any other integrated Atom board – many of
    which are more expensive. The additional horsepower of the 2.2GHz dual
    core Celeron enables - for the first time - the same platform to be used
    for a low-power Linux appliance, as well as a high-demand JPlay/Windows
    OS system.

    This processor includes integrated Intel HD graphics which has proved
    to be more smoother and more reliable when handling video sources up to
    720p - including Flash and BBC iPlayer HD. It will cope with 1080p but
    only when using VNC, and not without the occasional stutter. However,
    this platform is a much more capable multimedia companion that the
    second generation models, and of course has a full-spec PCIe 2.0 slot
    for the addition of upgraded graphics.

    Pico PSU 80W (yellow) ATX DC-DC converter with 12V input: £27
    the cheapest and best value way to tackle the primary supply problem.
    The cheapest - and silent - 80W Dc-DC converter version is actually the
    best, with lower noise figures and less tampering with the 12V rail to
    be supplied by a linear bench PSU. However, please note that if your PSU
    cannot be fettled to deliver less than 12.5V, you will need the red WI
    (wide input) version for an extra £10 or so.

    Linear Bench Power Supply: from £40
    There are
    many suitable models to choose from. Mandatories are: quiet transformer;
    passively cooled; low ripple and sufficient capacity. You will never go
    wrong by choosing an over-rated PSU: the lower its output relative to
    its maximum, the less noise it will generate. However, the Pico PSU is
    only capable of handling 7.5A at 12V, so don't go crazy. The basic model
    supplied in the T1 kit has a continuous capacity of 45W, and is capable
    of handling peak demand of 70W - and has a very low peak-peak ripple
    figure of 3mV. However, a system comprising of a single SSD or HD, with
    no attached USB peripherals other than a DAC or converter, should draw
    no more than 18W idle, and peak at around 30W when playing full-screen
    video. Bear in mind that every attached USB device requires up to 500mA
    at 5V, and that HDs draw up to 1A, whereas SSDs typically only require
    500mA. Most supplies of this type are designated as 13.8V, but have
    internal pots to bring the voltage down within range of the Pico PSu
    80W. All bench supplies we supply are preset to 12.2V. If you use a
    variable supply, set the voltage to precisely 12.0V.

    DC Cable: DIY from £15
    Terminate shotgun coaxial
    satellite cable having at least 1mm solid core connectors with good
    quality banana plugs at one end. At the other, strip the coax cable
    desolder the black and white power connectors from the Pico PSU (taking
    careful note of polarity) and solder the 1mm internal connector only
    (not the shield) to the freshly vacated input connector cups. This gives
    you an inexpensive, fully shielded, minimal connector DC lead direct to
    the PSU. Alternatively (easier, but worse) connect the 2.5mm input
    connector of the Pico PSU to a 2.5mm DC cable terminated with bare-wire
    or banana-plugs at the PC end. The T1 kit comes with a 1m length of
    suitable cable and high quality banana plugs.

  • Xigmatek Loki tower cooler: from £18 (case permitting)
    third generation recipes places greater stress on lower operating
    temperatures on the motherboard: cooler = less noise. Our preferred
    cooler on a budget is Xigmatek Loki which combines true copper
    heatpipes, good quality construction and excellent passive cooling
    properties at a bargain basement price. There are better coolers at
    higher prices that are easy recommendations, but we know of nothing that
    offers better value. The cooler comes with a fan – remove it. The Loki
    measures 134mmin height - a midget among tower coolers - but still
    requiring significant headroom – hence our case recommendations below.

    Corsair M4 Solid State Drive: from £35
    brands of SSD have poorly implemented drivers of firmware that create
    significant spikes in DPC latency and hard pagefaults. The Corsair M4
    has been the most reliable we've tested. The Intel DH61DL has a Mini
    PCIe slot that can be used to house an M4 mSATA drive if you're using a
    very small footprint case, or are on the tightest budget. However, the
    increased bandwidth and option to use a SATA filter makes our preferred
    choice a conventional 2.5" filtered SSD drive.

    SOtM SATA filter II: £45
    Each drive should be
    fitted with an SOtM SATA filters: even SSDs generate noise injected back
    into the signal path (see product page for details). The Mark II model
    contains several improvements over the Mark I.

    2Gb DDR 1333MHz memory: £12
    Use the lowest
    latency memory you can find or afford. For a Linux, JRiver or
    Foobar-based install a single stick of 2Gb DDR3 will suffice. For
    JRiver, Signalist or Phasure running under Windows 8, 2x 4Gb is

    Stillpoints fabric or better: from £30 per sheet
    case is already a pretty good screen: and gaps in the screen are
    necessary for ventilation. The aim here is to absorb reflections that
    would otherwise radiate back into the case, and shield critical parts of
    the signal path. Place patches underneath the CPU and graphics
    chipsets; above, below and to the side of the ATX socket, and around the
    USB output socket. The absorption characteristic of Stillpoints fabric
    are not hugely impressive: a number of specialised (thicker) materials
    are available that are considerably more effective - and expensive:
    starting at around £100 for an A4 sheet.

    Chassis: from £39
    Ideal low-end cases for the T1
    include the Coolermaster Elite 200 and CIT MTX003B: both are 'shuttle'
    format HTPC cases designed for Mini ITX boards. Both also accommodate
    higher quality full size optical drives and a full-sized expansion slot
    for PCIe cards (ie, Adnaco, SOtM or HDMI video). Crucially, both cases
    have headroom for the 134mm Xigmatek Loki cooler. If this format doesn't
    appeal (it's hardly a looker) the Streacom FC5, FC8, FC9 and FC10
    chassis are highly recommended: in this case, you don't need the
    Xigmatek cooler: all cases have integral heatpipe cooling - effective
    turning the whole aluminium chassis into a heatsink - like our Mac Mini
    modification. The Plex cases offer similar functionality, but aren't as
    attractive, don't have full-size expansion slots (horizontally disposed
    on a PCIe riser) - and are more expensive.

    Operating System: from £0
    Windows XP remains our
    OS of choice: it is compatible with every DAC, and always comes up with
    the goods via ASIO or Kernel Streaming. Our pre-stripped and optimised
    XP build, complete with authentic hologrammed licence pack is available
    for £40 as an option with the T1 kit. During JRiver playback, and
    running Task Manager and full network services, the OS is reduced to
    fewer than 140 active threads. Alternately, we can supply or recommend
    Linux MPD which works perfectly on the T1 platform. Dual-booting with
    XBMCbuntu gives a neat and fully-featured multimedia platform.

    Adnaco USB: £375
    We strongly recommend the Adnaco
    PCIe/USB system for USB3 output. It effectively firewalls all residual
    gavanic noise behind a battery or linear-powered USB socket. For further
    details, please see the product page.

    SOtM USB: £299
    The PCI-based USB 2.0 output that
    formed the centrepiece of the DAT1 and second generation recipes has now
    been upgraded to PCIe and USB 3.0. In certain instances, this may
    outperform the Adnaco system: if in doubt, try before you buy in our
    free home loan programme.

    SPDIF output: from £150
    The highest performing
    on-board SPDIF solution currently available is the new PCIe version of
    the stalwart ESI Juli@ card. It benefits significantly from two minor
    modifications: first, tapping the PCIe connection to inject a clean
    linear-generated supply and, second, hardwiring a BNC or RCA digital
    interconnect directly to its output - bypassing the DIN multi-connector.
    Full instructions are available to anyone purchasing this card from us.

    Northbridge cooling: from £10
    The pre-built T1
    comes with an upgrade Northbridge cooler and thermal paste that lowers
    the operating temperature of this chipset by 8-10°. After the Xigmatek
    or case heatpipe upgrade, the Northbridge chipset will be the hottest
    point on the motherboard and therefore the weakest link with regard to
    lowering temperature-related system noise

    Power Supply
    Upgrading the T1 to a tri-linear PSU
    brings bigger gains than any other single upgrade. If you have
    sufficient patience, we'll happily supply you 3m of shotgun coaxial
    satellite cable, six banana plugs, ATX shells, a linear power supply and
    full instructions for £299. Alternatively, we can supply a pre-built
    loom with  upgrade PSU and bus-bar ATX connector with breakouts for PCIe
    and USB for £399. Taking it up another notch for serious modders, we
    can supply the above with two dual-rail linear power supplies and
    instructions for injecting a fourth 1.5V rail directly to the memory.
    Alternatively, if you've opted for a silent Seasonic ATX supply, the
    addition of Core Audio ATX filters is a very effective way of lowering
    input noise on all rails, and breaks the 120W ceiling imposed by the
    Pico PSU.

    Optical Drive: from £40
    A few home truths first:
    slimline drives are generally fragile and unreliable. Full-sized optical
    drives (DVD of BluRay) can draw as much current as the rest of a
    well-specified PC put together and generate a larger EM field, as well
    as greater acoustic disturbance than anything else in the system.
    Furthermore the SM 'bricks' that power the external drives are typically
    of very poor quality in terms of ripple noise. It pays, therefore, to
    treat the administration of your music library as a different process to
    playback of your music library. The simplest solution is to buy a high
    quality Samsung or NEC drive, rip your discs, then unplug it. Or even to
    rip your CDs on another machine and transfer them via ethernet or
    sneakernet. Unless your machine is intended as a one box BluRay player
    it's hard to find a good reason to include it in the same chassis as the
    'transport'. Again, use of the Adnaco will mitigate some of these
    objections: if you have to build in an optical drive, provide it with
    its own PSU by cannibalising the SATA/PATA connector from an external
    caddy and unplug it when not in use. On no account should the optical
    drive be powered by the 12/5V section of a Pico PSU loom.

  • edited November 2012
  • That's very interesting. Thanks for posting it Alan. 

    I wonder how it running XP and JRiver compares to Audirvana+ on our Macs?
  • I wonder how it running XP and JRiver compares to Audirvana+ on our Macs?
  • Thanks for spreading the love, Alan! This recipe has taken a long time to arrive at, and in one or two crucial respects is significantly more sophisticated than other recipes out there: for instance tackling the primary power supply with one, three or four linear rails - and finally giving us the option of high-speed fibre optic isolation of the motherboard without truck with high jitter USB converters.

    We tend to agree with the HiFi World review of a Mac Mini modded to the max (tweaked OS + Audirvana + SATA filter + SSD + Paul Hynes linear PSU + passive cooling conversion + de-wireless): sounds good (five stars, no less!), but not as good as the best Windows / Linux builds. I'm quite depressed about it, because I'm a lifelong Apple fanboy.
  • No worries Mark, I like what you're doing and the way you're doing it even more. I will be following up with some kind of build next year, I hope.

    You and Dave (Uglymusic - resident Apple fanboy) should get together and weep into some latte at a posh coffee bar in your black roll-neck sweaters...
  • I'm looking to replace my ageing and increasingly noisy White MacBook when I've paid HMRC what's due to them over Christmas and the New Year.

    Maybe I should wait until you've (Alan) done your self-build before buying a new Mac mini.

    I do have one real stumbling block with a Windows-based machine, though. There's just one piece of software - JRiver - like it or lump it. The Mac playback marketplace is competitive and there is real potential for innovation.

    @ItemAudio. What's the situation with Linux these days? Is there a viable playback app, one that competes with JRiver and Audirvana+?
  • i do have one real stumbling block with a Windows-based machine, though. There's just one piece of software - JRiver - like it or lump it.
    I think you'll like it Dave. It's very usable, but also eminently tweakable for us folks.
  • I've seen it and played with it, haven't tried it here. 

    I do like the idea of having competing products to choose from.

    And, as much as I don't really like it, iTunes is the heart of my media sharing. I'd have to work out all the implications of replacing it.
  • Fair enough, that will/would be a hassle.
    Is it the fun of trying different products or a belief that competition drives up standards that appeals?
    I don't know iTunes very well. I use it to manage my iPhone and that's it really, so can't compare with JRiver.
  • I like to have the choice of more than on piece of software. Imagine a TT with only one cartridge available for it.

    On my Mac I have Audirvana+ for playback and iTunes for library management and media sharing.
  • edited November 2012
    I like to have the choice of more than on piece of software. Imagine a TT with only one cartridge available for it.
    You mean no fiddling...? no doubt...? no chasing my tail...? No endless spending...?
    Invent it Dave! manufacture it! Sell it! I will be there.

  • Or get yourself some Araldite and glue your current one in place.

  • There are loads of windoze options, I am no expert but I can think of JR River, Foobar, JPlay, XXHighend for starters.

    There was an interesting comment on pfm by a chap who builds very high end audiopooters, to the end that IF you get all the hardware considerations right, then a Windows OS sounds better than Linux and OSX. Mark echoed the comment, and endorsed it by saying he knew many system builders who had found the same.

    I doubt there are any absolute truths out there.
  • Thanks Alan. I was under the impression that Foobar wasn't really at the high end, and I didn't know the other two at all.
  • I asked a friend of mine to build a computer dedicated to audio, he chose the mother board the linear power supplies the fan les case, we used SoTM USB and SATA filters, chose JRiver And Jplay for playback, it works well Jremote on the IPad as a remote, but it didn't sound any better than my MacBook. SSd /Amarra in fact it didn't sound any different to my wife's standard Dell, using the same Weiss 202 dac.
  • That's a strange one, Keith.

    I would have thought with all those pints of difference across the three machines, there would have been some difference. What do you think is going on? Is the Weiss insensitive to what feeds it? Or some other reason?
  • Daniel Weiss always says that the important part is that bit perfect data reaches the dac chip, Weiss stuff is well designed and implemented, even the new Weiss Network Player the MAN 301 doesn't sound better than my MacBook into the Dac202, it is far more convenient to use though.
    As always keep an open mind and compare everything I your system to a known reference.
  • edited November 2012
    Keeping an open mind doesn't equal accepting everything at face value ;-)

    So really, the Weiss is the key here, not the player?

    Have you tried the different players into a different DAC to see if they still sound the same?
  • So has anyone had any further thoughts on building a minimalist windoze music server?  I wasn't going to, but having bought a Samsung laptop for work recently I tonight tried J River MC18 and JPlay.  The J River interface is very nice indeed and I like the idea of using it for displaying photos as well.  Too early to make a judgement on sound quality but I'm tempted to build a CAPS v2 server to see what all the fuss is about.  

  • I'm afraid not...
    I love JRiver though. It's a cracking piece of software that just keeps on giving!
  • So has anyone had any further thoughts on building a minimalist windoze music server?  I wasn't going to, but having bought a Samsung laptop for work recently I tonight tried J River MC18 and JPlay.  The J River interface is very nice indeed and I like the idea of using it for displaying photos as well.  Too early to make a judgement on sound quality but I'm tempted to build a CAPS v2 server to see what all the fuss is about.  

    I think - had I time and money, that I'd surely build the Item 'recipe' linked in this thread, for several reasons:
    • Support & advice from Mark
    • Split power supply to mobo

    That just about wraps it up for me. The new CAPS designs don't appear to offer much over & above (if anything) the Item design, and whichever road you go down, you need to throw a fair bit of dosh at it to do it 'properly'.

  • Yes it seems building the PC is relatively inexpensive, but adding linear power supplies, particularly with something like the Red Wine Audio battery unit significantly increases the cost.  There are cheaper PSU's available but this will be sitting in our lounge so can't look too industrial.

    I also wonder whether I have the technical knowledge to put together a 'puter and am baffled by the power supply part and how this connects up to one or more places inside the case.

    Lots more research required.

  • I like the thought of a Babbage engine sounding better with MP3 not that anybody would notice as all modern music sounds like clanking and screeching metal. ~X(
  • The CAPS design is frankly mental: why spend all that money on the very beautiful Red Wine battery, and funnel it through a single-rail input on the motherboard?

    For context, it's worth remembering that for three years, the creator of the CAPS recipe claimed that the primary power supply made no difference. Now, suddenly, it's essential to have a £800 battery. I would recommend anyone interested in doing a DIY build to examine the T1, CAPS and cMP recipes carefully.

    The beauty of the T1 is that you can start cheap and build on it, whereas the CAPS is a dead end. You can even switch approaches entirely from the standard, lean, XP-based version to the JPlay Way: adding memory, upgrading the processor and running W8: all on the same hardware platform. There's really no reason to use an Atom processor for audio in 2012, and especially 2013.

    Some DAC manufacturers see it as a badge of dishonour to admit their products reveal any differences in input cabling or transport specification. Others, like Wadia, dCS, Perreaux, et al have recently changed their tune, acknowledging that such things matter.

    A recent series of articles in HiFi Choice focused on differences between USB > SPDIF converters, and different versions of the Mac Mini - quite easily mapping measurable factors to audible outcomes. The DAC on which all their tests was based was the Weiss 202 . . .

    There's plenty of controversy around this subject, but it's interesting!
  • Item - your T1 design does look interesting.  Are there any linear PSU's that don't look like they've been stolen from a lab?  The T2 case looks nice and could happily sit in amongst my kit, but the PSU needs to look nicer or I suppose be hidden out of sight. Can the RWA battery be used with the T1?  If so, how does it compare to the linear PSU's (judged solely on sound quality) shown on your site?

    As I mentioned a few posts back, I spent a limited amount of time last weekend using JRMC and JPlay on a Win 8 laptop - didn't expect to like JRMC but was quite impressed with its flexibility.  Lots more listening required but my initial impression is that this combo sounded slightly better than Audirvana on my MBP.

  • There are many options: first, you can fit the PSU in the T2 case, but it sounds worse.

    When it comes to off-the-shelf linear PSUs there's a pretty strict cheap / good / WAF triangle to draw a line through: you can have good and cheap, but not pretty; if you want good and bling, it won't be cheap.

    It's fairly easy to recase the innards of a lab PSU, and hardwire the DC outputs while you're at it. Or, you can step up to the Paul Hynes / Fidelity which (from us) ranges between £350-600 depending on capacity.
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