Tír Na HiFi

Given the rapidly-changing plethora of options available to build computer audio products - and the increasing trend toward integration of 'smart' devices - the fourth generation of 'recipes' in a line dating back to 2008 suggests three different ways to build low-noise, transparent-sounding streamer/players.

The availability of higher quality power supplies and DSD-capable, Class 2.0 DACs has changed the game for a USB transport in a way that makes it easier than ever to DIY an open-platform computer source. Off the top of my head, here are the first five of many benefits of doing so:

1. Only an open computer will play any file from any source now and in the future. Any proprietary 'streamer' will be to some extent locked down, limited and one step behind. Future developments, such as the unheralded arrival of Qobuz as a major player this year, are easily integrated.

2. You choose your storage, and you upgrade it when you like. Many 'streamers' have no onboard storage. Onboard storage is cheap, convenient, obviates the need for a NAS, is faster, and sounds better.

3. You choose your interface. Most open-platform players for Mac, PC or Linux have several control apps for Android and Apple iOS. They can often be controlled from the browser of a Chrome OS or any other laptop/desktop machine, whereas proprietary players will lock you down to a single interface, sometimes committing you to a single mobile platform.

4. You save money. Seriously, anyone capable of wiring a plug can do this and save hundreds of pounds/dollars/groats.

5. It sounds better. Because you're using better parts than a mass produced streamer, and can configure your machine way beyond their spec, it will sound more like it's not there; less 'digital'; less like a computer.

In spirit, these recipes are indebted to CICS / cMS Memory Player who published the first computer audio recipes back in 2006 (see timeline here: http://www.itemaudio.co.uk/forum/viewto ... =15&t=2101). They owe nothing to Computer Audiophile - every generation of whose recipes post-date ours by several months and with which we encourage readers to compare/contrast!

Although those who know us will be surprised to hear it, most of the Phase IV recipes abandon linear power supplies. It was quite a culture shock for us, too. In fact, it took us three months to admit that the latest generation of off-the-shelf switching ATX supplies have finally reached the point where they are as good as the multi-rail computer-specific linears we've been recommending and building since 2009 - long before anyone else. This is great news for DIYers.

The venerable Pi offers further encouragement for DIY computer builders: in some respects it's a perfect device for audio; in others, not. More on this later. And finally, Gigabyte's announcement of motherboards built for USB output to DACs provides greater incentive to simply plug-and-play your own system. It's never been easier to get this right, the choice has never been wider and there's never been less of a need for 'special sauce'. You never had it so good.

Plus, six years of publishing USB-specific computer audio recipes has finally given me licence to name something after my favourite ant-based film. On with the show . . .

The P1:
P for Player; 1 for entry-level; P1 for Pi.

The Pi is too good to ignore and it makes a killer low-cost build, although it will involve a tiny bit of nursery slope soldering. It puts a big tick in the 'simple is good' box: running a 5V supply and offering great extensibility. Plus, it's cheap. On the downside, it's USB implementation is appalling for audio. On the upside, it's brilliant as an I2S source.

P1 Basic (from under £100)
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- Rev B Raspberry Pi: £30
- TekDevices ES9023 board: £35
- Stontronics T2526ST or Teradak Teralink T2 Linear PSU: £15/£50
- USB injector cable with Micro USB adaptor: £5
- Case from £5-100.
- A £30-40 interconnect
- SD card (from £5)

First, the trickiest bit: solder the eight P5 header joints that come with the TekDevices board to the Pi Rev B board. Desolder the RCA sockets from the TekDevices DAC board and solder your RCA leads directly to the board, after removing one set of connectors. This is crucial to obtaining the best quality output, and the best free upgrade you'll make.

Of all the low-cost daughterboards for audio, the TekDevices ES9023 one is currently the best-sounding/measuring and the ESS chip has built-in reclocking for I2S input - one of the most critical features of this build. Alternatives we played with during 'development' (the P1 barely qualifies for the description) that impressed us included the similarly-priced IQAudio PiDac based on the Burr Brown/TI PCM5122. Down the list a little way - and not requiring solder of the P5 header - are the Wolfson and HiFiBerry boards, which are both OK.

The Stontronics is the cheapest low-ripple PSU currently available, but it's only just capable of running the Pi + DAC. The 30W Teradak Teralink-X2 is a much higher quality device for a few quid more than has variable output that can be set to 5V. Please note however that this unit does not presently have CE certification. Retaining the Pi's 5V input (rather than bypassing it with 3.3V) enables you to use its HDMI output and multimedia functionality - plus, the DAC needs both rails. Alternatively, there are a number of open-frame linear supplies offering single-digit p-p noise figures for less than £50 for the braver DIY builder. Or, of course, you can make your own.

Assemble in your choice of case - I like these: http://www.barchdesigns.com

Grab an image of Raspbmc, plug and play. Airplay support is configurable out of the box.

Audiophile Upgrades
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If you want to get more serious about your Pi build . . .

Replace the ES9023 with an ES9018k2m-based I2S board like this this one and feed it with a 3 wire I2S signal connection from the Pi. Boards and power requirements vary.

Bypass the Pi's onboard 5 > 3.3V linear regulator and power it via a 3.3V LiFePo battery and upgrade the 19.2MHz with a Tentlabs or similar module fed with a separate clean 5V supply (ideally battery).

Hardwire better interconnects.

Install Volumio/MPD instead of Raspbian. This, and the 3.3V mod will rob the Pi of its ability as a multimedia player (no video output or playback), but it will fairly significantly improve its performance.

The P2:
P for Player; 2 for Better.
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For all that Pi is cute and cheap, it has fundamental limitations: we can't easily use multi-rail supplies or USB DACs (without making serious compromises), resample to DSD, or install drivers for DACs that don't support Linux (although these are becoming a rarer breed). Also, the Pi DAC boards are couth and tuneful but not exactly boxes of fireworks. For that we need more power - in every department.

The J1800 board is a neglected gem for audio: overlooked (as Celeron often is) between the glitzy new NUCs and the 'proper' i-Series models. However, compare the spec of the Gigabyte J1800N with a Beaglebone Black or Pi . . .
http://www.gigabyte.com/products/pro...px?pid=4881#ov
We get fast interfaces, fast memory (and more of it), 22nm fab, a much faster on-board dual core processor, proper SATA ports, proper USB (2 and 3), proper Gigabit Ethernet, proper expansion ports (mPCIe and PCIe), on-board passive cooling, industry-standard board size for wider case selection, etc, etc.

And the really scary thing is this: it's only £15 more than the Pi. It's cheaper than a Beaglebone. If you can live with a larger form factor, it's the perfect base for an audio PC - and it will even do 1080p video (at a pinch).

What mainly makes it suitable, though, is its multi-rail power input. The most important thing about a PC build for audio is its primary power supply. Previously that would have opened the door to inexpensive linear AC-DC supplies funneled through a Pico PSU DC-DC switcher (total cost: around £70). But then it all changed . . .

Early this year, a new range of - gasp - switch-mode ATX power supplies was released that finally rivaled the performance of the multirail PSUs we've been developing since 2009. About time. The knack, though, is to specify a PSU that's massively over-rated for our purpose.

A J1800N build, as recommended here, will draw around 20W at idle, and peak at 50W - depending on configuration. Why use a massive 750W supply then? Because when pulling less than 150W, these next-gen SMPs produce ripple figures on all rails between 6-9mV p-p.

For perspective, our best multirail linear PSUs deliver ripple figures ranging from 2-5mV in their sweet spot. But because they're rated for between 6-10A (depending on which model you specify), real-world figure rise into double figures as the supplies heat up and are called on to operate in the top half of their operational range.

Think of it like a pint-sized turbocharged engine screaming away at 7K revs, versus a big lazy V8, barely ticking over. Same torque: less stress.

A good single linear or battery like the Red Wine Audio Black Lightning recommended in the confused Computer Audiophile recipes produce extremely clean output, but if you funnel it through a PicoPSU, all the hard work is undone by a hot little switcher generating real-world ripple figures anywhere from 40-150mV p-p.

The benefit of cleaning up all those rails is considerable. Any good multi-rail supply will hugely outperform a £1000 battery jammed through a noisy £25 DC-DC converter.

The economic argument for the new SMPS is compelling. Since 2009, the cheapest multi-rail supply for a computer cost £400 including the ATX loom - and it was a big, ugly lab supply with variable output. The next most affordable multirail linear was £600 and it didn't work with all motherboards. From there up, the Teradak, Paul Hynes and Core Audio products all run well in quadruple figures: £1200-2400.

Now we have comparable levels of performance in a universally compatible, off-the-shelf supply for £120. Very happy days. Although this supply doesn't quite match the performance of exotic linears or - particularly - batteries, it is fantastic value, and effectively obsoletes a slew of middling upgrades. Basically, go for this, or go with batteries. Nothing else makes sense.

P2 Core Ingredients: £499
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Gigabyte Celeron J1800N: £50
Leadex SuperFlower Gold 750W (see bench tests here): £120
64Gb SSD: £40
4Gb DDR3 1600MHz: £40
Silverstone Grandia GD04 case: £95
SoTM SATA filter: £40

The Celeron has enough horsepower to handle DSD resampling from PCM, which is A Good Thing. However, Linux support for this is patchy. When it does come online, we will offer a free plug-and-play disk image for the P2. Meantime I recommend XBMCBuntu for a multimedia machine, or Volumio/Daphile for an audio-specific machine - all free. Airplay support is configurable out of the box. You can even install Windows if you have/want to pay for a licence.

Turning this platform into a 'Player' capable of streaming anything from anywhere is simply a case of adding a small form-factor D-A stage capable of playing DSD. Three, low cost, great-sounding DSD DACs can be installed in the Grandia 04 case for around £200:
- iFi Nano
- Fostex HPA4
- Light Harmonics Geek Out

It's hard to go wrong with either. Connect them via the J1800N's internal header and use one of the redundant PCIe slots on the back of the case for a one-box solution. Leave the DAC in its original casework, which will provide necessary shielding. Alternatively, run a dual-conduit USB cable from the USB3 socket to the external DAC of your choice - in which case, the P2 becomes a low-rent version of the T1.

The J1800N has a bonus rough-and-ready on-board DAC with 3.5mm outputs and a headphone socket.

Storage can be upgrade internally to 3Tb using dual 2.5" drives. The best alternative to the GD04 case (440 mm (W) x 150 mm (H) x 323 mm (D)) is the £20 more expensive Fractal Design Node 605 - better looking, and a little more robust, but 10-15mm bigger in all dimensions.

It goes without saying, like all our recipes, the P2 is completely silent running. If you can accommodate a CD-player-sized box, the P2 is the best bang-for-buck computer audio player/streamer/server currently available. More detailed build instructions will follow on our website for absolute novices . . .

The T1
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For many years, 'T1' has been associated with some of the best digital transports available. Since 2011, it's also been the name of the best computer audio recipe.

The 2014 edition takes advantages of some new developments that didn't exist last year, and we felt it best to recommend two versions: one, showing what can be done on a minimal budget that nonetheless offers a real improvement over an off-the-shelf PC for connection to a USB DAC - and the other a cost-no-object exercise chasing the best available performance . . . by which we simply mean 'transparency'.

T1 Basic Edition: c£625+
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Fractal Design Node 605 Case: £120
Gigabyte B85N motherboard: £65
Haswell G3420 processor underclocked to 2.4GHz: (£50)
Leadex 750W PSU: £120
64Gb SSD: £40
4Gb RAM: £40
Alpenfoehn Panorama or similar heatsink : £25
SoTM SATA filter: £40
3m 5100 RF material (1x sheet): £30

For non-DSD-resampling: Volumio or Daphile to taste.
For DSD-resampling systems: Windows 8.1 + Foobar (until JRiver improves) + Quad Core processor upgrade

A power-injecting USB cable (like the iFi Gemini, KingRex uArt/Craft or Lightspeed) is strongly recommended.

The Gigabyte B85N is the cheapest board to feature Gigabyte's 'DAC UP' technology that filters the outgoing 5V rail from the motherboard specifically for connection to external DACs. The combination of this board with the off-the-shelf Leadex Gold 750W is potent and very, very easy for a novice to build. It marks the first Haswell platform we've recommended. The G3420 processor and 4GB RAM under Linux is perfectly adequate for DSD playback and even (just about) DSD resampling. If not DSD resampling, I strongly recommend underclocking the processor to 2.4GHz.

Full build instructions are available on our website.

T1 Audiophile Edition Upgrades: to c£2500
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The basic T1 is a fine platform from which to build a state-of-the-art audio computer. For ultimate results, the board requires multiple clock upgrades, battery power supplies, mains isolation, ATX filtration, improved RF/EM absorption, non-ferrous case, vibration damping and - most crucially - clock-upgraded USB output stages.

There are three ways to step up from the basic Leadex SuperFlower 750W supply:
1. Top and tail it with the Core Audio 24 + 4 ATX filters and Trichord Isolation Transformer (£650)
2. Use the Red Wine Black Lightning PSU and HDPlex DC-DC converter (£1100)
3. Use a three- or four-rail linear PSU (from £750-2000)

The right one for your build will depend on:
a) What power filtration and isolation / ground loops you already have in your system
b) Budget
c) What other rails you require and what USB card you're using

In terms of measurable, delivered noise, the battery + DC converter is slightly higher than the other two, but does put you off-grid, and that has additional advantages in some systems. However, a full discussion of this is outside the remit of this already lengthy thread - see our website for further details coming soon.

Unfortunately, each DAC responds best to different approaches: typically, with opto-isolated USB stages, improved clock implementations such as the SoTM and JCAT cards tend to work best. On other DACs, the Adnaco fibre-optic system with a battery power supply tends to be favoured. The PPA USB card is also a good value option on a smaller budget. Some converters respond extremely well to software resampling to DSD; others not so much.

For the usual computer forum users...

Is this an advertisement and from a commercial provider? In which case ....

You might want to run a background check . . . we've freely published computer audio recipes since 2008. Everything in them is available from any good electronics retailer. No special sauce.

But hey - stay frosty!

item_audio wrote:You might want to run a background check . . .

I shouldn't have to... a polite introduction would save all that.

mark
did you ever test the passive seasonic atx supplies?
how does the pico + linear compare to the leadex?
im a little skeptical :)

the problem with the dac-up is that it still sources the +5v from the motherboard, its a sort of half way sort of thing and still requires all the further modding :(

fractal make lovely cases :)

were a bit of a divided bunch here
theres those who are really into ca and want the best and those that cant get far enough away from it
there is a couple trying it out low level style but not many

think the bbb and tp botic (properly implemented) will clean up the bottom half of the ca market (maybe more)mostly because of sq but also the simplicity and foot print it can have

Sorry to have caused offense.

Hi, I'm Mark. I joined TirNaHiFi last year. I thought it was a good place to talk about computer audio.
We've done a little bit to make it more interesting for the best part of a decade.

I run Item Audio. As well as selling stuff, we published the second detailed 'recipes' for audio computers back in 2008 for DIYers to build things that would help the DACs we sell to sound better - a bit like Computer Audiophile, but earlier and better. Hence Computer Audiophile.

We did the original Mac Mini mods, before Mach 2 came and went.

Right now, I'm quite excited/disappointed by the fact that higher quality off-the shelf IT components can give unprecedented results without faffing about too much with mad mods. Hence the update to the third generation recipe which featured parts now hard to obtain.

item_audio wrote:Sorry to have caused offense.

No offence taken or intended Mark.