Monday, November 21, 2011

Audiophile silliness, now on a motherboard!

A couple of weeks ago I got hollered over to the dismantle bench -- "you have to see this" or something of the sort. Here's what they had inside the case:

It's the usual mess of wires and junk -- but way at the back, there's something that you will probably never again see on a motherboard.

That's right -- my favourite dinosaur. A vacuum tube.

This is the AOpen AX4B 533 motherboard. It's marketed at the audiophile market; the vacuum tube is part of a built-in stereo amplifier. The fellow who bought this brought it in with the original manual, and part of the original cardboard box it came in was taped into the inside of the case. He or she was pretty proud of this one.

The manual is a catalog of hyperbole:

Driven by this premise [the lacking overall quality of PC audio], a group of geeks at AOpen's Motherboard Division began to think about a fusion of the latest technology with Thomas Edison's discovery dating back to 1880 -- the conversion of alternating current into direct current through a device called The Vacuum Tube.

For years audiophiles and musicians have appreciated the warmth and tonal quality that flows from sound that is reproduced with the utilization of the vacuum tube...
 ...and it goes on for pages, gradually working itself into a froth...
With tube technology, music is more musical! Jimmy Page strikes the guitar strings on "Stairway to Heaven" and Angus Young of AC/DC's "Black In Black" share one common attribute-- It is the vacuum tube that powers their guitars' souls that express what they want to sound like and what the listener likes to hear.
Sic et cetera. Yikes. Later, there's the 1970s-stereo-magazine-style centerfold:

Yup, I'm imaging a discerning consumer scrutinizing the graph of mA (milliamps) vs. V (volts) and determining ... what exactly?

Thanks for that, AOpen. And I'll spare you all of the marketing bumf on MultiCap(tm) coupling capacitors, Vishay high purity ceramic substrate resistors, the 24K gold-plated tube socket, and the "famous 'Silent Conductor'... Constant Q Stranding... reducing the internal rise in inductance... [incorporating] Cross-field Construction..." of the Cardas cable that I suppose was probably included in the box with the motherboard.

I have a few reasons to kick AOpen around.

First, they've cottoned on to the primary marketing mechanism of high-end audio equipment: confuse the customer until they're suitably impressed and will buy anything. It's annoying.

Second, the idea of sticking a tube amplifier onto a motherboard is inherently dumb. There's no way you can replace or upgrade one of the two. Motherboards aren't meant to be serviced and have a typical life of just a few years before they're thrown away. (Well, not if Free Geek has anything to do with it.) On the other hand, tube amplifiers are meant to be timeless, simple, long-lived devices -- a textbook opposite of a motherboard.

What else? Well, look what's behind the vacuum tube:

Those three white PCI slots, if used, will be pretty much guaranteed to send lots of jagged digital RF (radio frequency) noise right through the audio amplifier section of the board. Heck, even without them there's still ungodly amounts of noise running around inside a computer chassis. It's like putting a metal band in a nursery. Or putting Ayn Rand slogans on yogawear. The two should never be combined.

And I could go on forever about this, but here's the biggest disappointment with this motherboard:

If you've worked at Free Geek for long, you'll spot the problem pretty quickly: three bad capacitors. In total there were 14 blown capacitors -- every single one of the larger capacitors made by Lelon. (The three big ones above are Lelons; the row of similar-sized caps visible on the left-hand side are made by another manufacturer and weren't affected.)

The story behind these is actually pretty interesting. Several employees working for a Rubycon, a Japanese electronics manufacturer, left and took a stolen electrolyte formula with them to Chinese competitor Luminous Electric. But the formula they stole was incomplete or faulty. Many capacitor manufacturers -- including Lelon -- bought the bad electrolyte and sold it in their own capacitors. After a short lifespan the electrolyte breaks down and the capacitor fails.

And, just like that, your fancy audiophile high-end motherboard stops working reliably. But more likely than not, you don't care -- it's a year or two old and no longer exciting anyway.

Having jawed themselves rabid with all the promise of this motherboard, what AOpen actually sold was a time-bomb.

So I've ranted about the flaws of this motherboard for long enough, but I have to admit that I needed to see -- or should I say hear -- it in working order. I cycled up to Main Electronics and bought $15 or so worth of new capacitors. I pulled all the old capacitors with a soldering iron:

...and soldered in the new ones...

...and fired it up.

She works! If a little strangely -- it won't restart unless the power is forcibly toggled, so it may have sustained some minor internal injuries from its time with the faulty capacitors.

I can't say I noticed any difference in tone. But maybe I have tin ears.

(p.s. If you really want a high-quality vacuum tube powered stereo system with a computer as the audio source? Get a good-quality external audio card, get a vacuum tube amplifier, and plug the two together. Just don't expect garden-variety MP3s or youtube videos to blow your mind -- it's just top-quality lipstick on the same old pig.)


  1. wait you're using an external audio card so isn't the onboard audio not being used at all at this point???


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