Audio Console (Work in Progress)

Introduction

Some things in life just take longer than they should. I started this project quite a while ago when I picked up a FlexATX motherboard from an internet surplus dealer. The concept was simple. Build an extremely cheap computer, make it as compact as possible, treat it like a console device (like a CD player for instance), place my entire music collection on a hard disk in MP3 format, and place the unit in the bedroom so I can listen to my favorite tunes.

From the outset, there were a few obvious challenges. My ideal box would be standalone; it would not require a TV or monitor for video output. Ideally, it wouldn't need a keyboard either since those take up too much space. It had to have built-in amplifiers so that I wouldn't need a seperate stereo amplifier. And it had to boot quickly and be silent. And let's not forget that it had to be dirt cheap.

As luck would have it, I just didn't have the time to work on this thing. When I finally made some headway in early 2004, the results were dissapointing. Here's what I had come up with:

Here are two pictures; one with the drawer closed and the other with the drawer open. I liked the drawer idea for the keyboard but the entire case was just too bulky. Not shown is the rest of the box, which rose a few more inches to enclose all the hardware. Made of MDF, the case was heavy and ugly. The straw that broke the camel's back was the hum in the amplifiers I installed (also not shown). Back to the drawing board.

New life for an old VCR

If there's one nice thing about old VCRs, it's that they are fairly deep. I had an 15 year old Sharp VC-A607U whose belts finally bid farewell last year. A little measuring confirmed that I could fit my FlexATX system into this plastic case if I was willing to strip my system requirements to the barebones. Given how long I'd spent on this project (I hate having stuff sitting about half-finished) any compromise seemed like a good idea.

The new console will start out as nothing more than a computer. It'll have a single hard disk, a power supply and motherboard. The keyboard is wireless (infrared) so it's not tethered to the box. That's pretty much it ! Anything else I may add to the box will depend entirely on the available space in the box. For expansion, there will be at least one exposed USB connection for either a wireless network adapter or mass storage device.

Of course, the entire unit needs to be cheap; otherwise I'd just buy an iPod and be done ! The simple truth is that the single most expensive item here should be the hard disk drives. Everything else is either recycled, taken from my spare parts bin, old/used "stuff" or obtained at a steep discount. Here's the bill of materials.

The total cost comes out to about $91, not counting miscellaneous hardware. Now for a quick look at the guts of this system.

The Motherboard

The ECS motherboard I'm using has several features that made it an ideal candidate for my console. It has a built-in wireless keyboard interface so there's no umbilical cord dragging about a keyboard. The FlexATX form factor is smaller than microATX through bigger than mini-ITX. The price was great, especially since it included the mid-sized keyboard. Since I don't meed a lot of CPU power, a socket-370 processor gives me lower power dissipation and therefore less fan noise than a faster more modern CPU. Integrated graphics, network and sound removes the need for add-in cards thus keeping the height down to a minimum. The TV-out feature means I can drive a standard television and don't need a computer monitor - perfect for use next to a TV. In short, I couldn't ask for a more suitable motherboard for the money.

On the down side, the particular version of this ECS motherboard didn't have the audio I/O connectors installed on the motherboard so I had to wire them up seperately; not that big a deal.

An 800 MHz (6.0 x 133FSB) CPU is more than enough power for decoding MP3 files. To reduce power consumption and heat, I can underclock the processor in the BIOS by running the front side bus at 66 or 100 MHz.

Cooling the CPU requires two parts - a socket-370 heatsink and a fan. The heatsink is nothing special. The fan is a squirrel cage slot fan (photo left) with the I/O bracket removed. It is mounted to the underside of the case lid with double-sided foam (photo right). The exhaust blows over the disk drive and the power supply heatsinks. To reduce noise, a 33 ohm 1/2 watt resistor is added to reduce the voltage from 12V to 8.5V.

VCR Case

After gutting the VCR of its internal components (photo left), I removed most of the plastic obstacles with a Dremel tool (photo right). The differences in the photos are subtle. The most obvious change is the removal of a wall 2/3 of the way back on the left half of the box. I left some of the plastic in place to help stiffen the box. The resulting unit contained two basic areas. The motherboard sits on the left and towards the front. I would have liked to push it back further but it just didn't fit that well back there. Furthermore, the ATX power cable would be trickier to install without removing more of the plastic ribbing. The power supply and disk drive sit on the right side.

On the front, I mounted a push-button on/off switch behind the flip-down access panel.

Inside, I mounted a green power-on LED and the IR keyboard sensor.

The original door for the VHS tape well has not been installed yet. This gives me easy access to the secondary IDE connector which I still need to hook up a CD-ROM drive - it's still the easiest way to get data on and off the unit.

11-March-2005

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