There are some hardware projects where the interesting part isn’t making an old component work again. The interesting part is finding a use for it that its manufacturer never quite intended.<\/p>\n\n\n\n
This is one of those projects.<\/p>\n\n\n\n
At its heart is a Creative Sound Blaster X-Fi Platinum Pro \u2014 a product originally designed as a PC sound card accompanied by an external control and I\/O unit. In this project, however, the X-Fi becomes something closer to a dedicated digital audio processor, with a small computer built specifically around it.<\/p>\n\n\n\n
The idea started with a simple question:<\/p>\n\n\n\n
What if the computer existed primarily to serve the sound card?<\/strong><\/p>\n\n\n\n The computer is built around a GIGABYTE GA-J1800N-D2PH<\/strong>, an extremely compact Mini-ITX motherboard based on Intel’s low-power Celeron J1800 platform.<\/p>\n\n\n\n It is hardly an impressive specification by modern PC standards. That is precisely why it works so well here.<\/p>\n\n\n\n There is no need for a powerful processor, discrete graphics card, large storage subsystem or conventional ATX power supply. The computer’s job is relatively modest: provide a Windows XP environment for the X-Fi and its associated software while also allowing the sound card to perform the audio processing for which it was designed.<\/p>\n\n\n\n The system uses an SSD containing Windows XP SP2<\/strong>, together with the appropriate Danile_k X-Fi drivers.<\/p>\n\n\n\n The choice of Windows XP is deliberate. This is not a case of putting a modern operating system on old hardware simply because it happens to run. The operating system is part of the hardware’s identity.<\/p>\n\n\n\n The X-Fi belongs to the Windows XP era.<\/p>\n\n\n\n So does the software ecosystem surrounding it.<\/p>\n\n\n\n The GA-J1800N-D2PH is a Mini-ITX board, while the X-Fi is a conventional PCI card. The physical arrangement therefore presents an immediate problem.<\/p>\n\n\n\n The solution is a 90-degree PCI riser<\/strong>.<\/p>\n\n\n\n Instead of mounting the X-Fi vertically as it would be in a conventional desktop case, the riser allows the card to lie horizontally inside the custom enclosure.<\/p>\n\n\n\n This seemingly small change is important to the entire design. It makes it possible to build a very shallow chassis around the dimensions of the X-Fi’s external unit rather than designing a conventional PC case and trying to fit the audio hardware afterward.<\/p>\n\n\n\n The sound card is therefore not an expansion card that happens to be inside the computer.<\/p>\n\n\n\n It effectively determines the computer’s physical architecture.<\/p>\n\n\n\n Power is another area where conventional PC hardware doesn’t make much sense.<\/p>\n\n\n\n The system has extremely modest power requirements, so a normal ATX or SFX power supply would be excessive both electrically and physically.<\/p>\n\n\n\n For the current prototype, a PicoPSU<\/strong> is being used.<\/p>\n\n\n\n The long-term goal, however, is to find a small, good-quality OEM-style power supply from the kind of compact Dell, HP or Lenovo office machines that used similarly low-power hardware.<\/p>\n\n\n\n The ideal supply would be physically small, quiet and capable of providing considerably less power than a conventional desktop PSU.<\/p>\n\n\n\n There is little point in putting a large, high-power SFX supply into a computer whose processor was designed to run at only a fraction of the power consumption of a modern desktop CPU.<\/p>\n\n\n\n A custom power supply would certainly be possible, but designing a proper ATX-compliant supply is considerably more work than simply generating the required voltages. Startup sequencing, protection, standby power, PWR_OK, transient behavior and mains safety quickly turn a seemingly simple project into a substantial engineering exercise.<\/p>\n\n\n\n For this build, that effort is better spent elsewhere.<\/p>\n\n\n\n The most interesting feature of the system isn’t actually Windows XP.<\/p>\n\n\n\n It is the way the X-Fi itself is used<\/strong>.<\/p>\n\n\n\n In addition to its normal functions, the sound card can accept a digital signal through its S\/PDIF input and perform hardware decoding of Dolby Digital and DTS<\/strong> signals.<\/p>\n\n\n\n That changes the character of the project considerably.<\/p>\n\n\n\n The computer can function as a conventional Windows XP audio machine, but the X-Fi can also act as the processing stage for an external digital audio source.<\/p>\n\n\n\n Conceptually, the signal path can therefore look like:<\/p>\n\n\n\n S\/PDIF source \u2192 X-Fi \u2192 Dolby Digital\/DTS decoding \u2192 analog multichannel output<\/strong><\/p>\n\n\n\n The PC becomes a host for a piece of early-2000s PC audio hardware that contains capabilities which are surprisingly relevant to a modern DIY audio system.<\/p>\n\n\n\n It isn’t trying to replace a modern AV receiver.<\/p>\n\n\n\n It is doing something much more specific:<\/p>\n\n\n\n preserving and repurposing a particular piece of PC audio technology as a dedicated appliance.<\/strong><\/p>\n\n\n\n The enclosure is being built from aluminum, using a combination of bent aluminum sheet and aluminum profiles.<\/p>\n\n\n\n Its dimensions are determined primarily by the X-Fi Platinum Pro external unit.<\/p>\n\n\n\n The computer case underneath has the same width as the external X-Fi box<\/strong>.<\/p>\n\n\n\n The front of the computer uses a black acrylic panel whose width matches the black section of the X-Fi’s front panel. The intention is not to make the two units merely match.<\/p>\n\n\n\n The intention is to make them appear to be one continuous piece of equipment<\/strong>.<\/p>\n\n\n\n From the front, the lower computer should visually continue the X-Fi’s fascia.<\/p>\n\n\n\n That is an important distinction.<\/p>\n\n\n\n This isn’t an old PC placed inside a nice case. The enclosure is being designed as though Creative had originally manufactured the computer as part of the X-Fi system.<\/p>\n\n\n\n The result should look less like a desktop computer and more like an unusual piece of period hi-fi equipment.<\/p>\n\n\n\n None of the individual components is particularly exotic.<\/p>\n\n\n\n The motherboard is a low-power Mini-ITX board.<\/p>\n\n\n\n The X-Fi is a sound card.<\/p>\n\n\n\n The SSD is an ordinary storage device.<\/p>\n\n\n\n The PicoPSU is a conventional compact PC power solution.<\/p>\n\n\n\n But their combination produces something that none of these components was originally intended to become.<\/p>\n\n\n\n The J1800 is no longer being asked to be a general-purpose PC.<\/p>\n\n\n\n The X-Fi is no longer merely an audio peripheral.<\/p>\n\n\n\n The external Platinum unit is no longer simply a breakout\/control box.<\/p>\n\n\n\n Together, they become a small, dedicated Windows XP digital audio appliance<\/strong>.<\/p>\n\n\n\n And that is exactly what makes the project interesting.<\/p>\n\n\n\n The hardware isn’t being preserved simply because it is old.<\/p>\n\n\n\n It is being preserved because, when its original components are rearranged around their particular strengths, they can still do something worth building.<\/p>\n\n\n\nThe Core Hardware<\/h2>\n\n\n\n
Making PCI Fit<\/h2>\n\n\n\n
The Power Supply Problem<\/h2>\n\n\n\n
More Than an XP PC<\/h2>\n\n\n\n
The Case Is Part of the Project<\/h2>\n\n\n\n
Why This Is “Off-Label”<\/h2>\n\n\n\n