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AOpen Debuts The Funniest Motherboard Ever
Anonymous Coward X-11 writes "Has AOpen gone flipping nuts by putting vacuum tubes on its motherboards?
AX4B-533Tube
No, it's not replacing logic ICs with discrete components. The tubes are part of the on board audio. Not sure if they are serious about this. April 1 was two months ago." As an owner of a tube headphone amplifier I applaud AOpen's move to accomodate the high-end audio enthusiast, while simultaneous wondering about the ability of a switched psu to properly drive a tube amplification stage cleanly. There's no way this is for real, right? Right? Here's a link that seems to work pretty well. And this looks pretty, well, real. Update: /. reader Jedi1USA noted that HardOCP has more pics of the board.
Tubes tend to produce even-order harmonics when they distort. Transistors (except MOSFETS -- others?) produce odd-order harmonics. Of the two, odd-order harmonics are much more annoying from a psycho-acoustic standpoint and lead to what many describe as a "harsh" sound. Tubes also have the advantage of not clipping hard (producing a DC output) because they have to run through transformers to drive speakers and, as we all know, transformers don't pass DC.
That's a gross oversimplification that leaves out much that I know, some that I think I know but don't really, and stuff other people actually know that I don't know at all. But that's the gist of it.
Is it of any use on a motherboard? Sure. It's great gimmick to sell to idiots. So how do they get stereo out of a single tube? It looks too small to be the two-tubes-in-one variety.
I see only one tube and, considering the specs mention 5.1 surround sound, I can't see how this tube could be part of the pre-amp/power amp signal chain. I've owned a few tube amps in my time (stereo, guitar, and bass) and usually there's a couple of 12AX7s in the pre-amp stage and a few 6L6s or EL-34s in the power amp stage per channel. This is one small tube for six channels.
k.
"In spite of everything, I still believe that people are really good at heart." - Anne Frank
I was really hoping for this to be for analog computing.
In the field of chaos theory, and cryptography, and countless others, analog computing is great. To have an analog accelerator, much as one has a 3D accelerator, or floating point module, would be great. The tubes could be rewired on the fly, like an FPGA, allowing the programmer do all kinds of things. Imagine if the programmer could work in voltages, with chaotic effects giving true random numbers. Using this chaotic data, you could form clouds and other random events for games, perform neural network calculations and countless other things.
The analog systems helping the digital ones would be quite a revolution.
-twb
To recap what's said a bit further down, a normal computer power supply could not put out the voltage needed to even warm up such a tube (do you really want to wait an hour for your audio to get up to speed? Consumers are impatient; they want everything NOW, which is why they have big capacitors in TV sets for this so-called instant-on that we take for granted.)
:)
As someone who's worked in music stores for years, and with computers even longer, i can say with some authority that a small onboard tube of the kind shown here (looks like a 12AX7) would be useless for output; you see this kind of thing more often in tube preamps for input, so it doesn't seem logical. others have noted the RF interference, and the fact that a *single* tube would only result in mono audio - a one-tube solution would be more suitable for an AM radio or a guitar distortion unit. I would point out the sheer size of the component (about 3 inches tall) and the fact that it gets as hot as a light bulb as factors that would mean *something* in the computer would start melting (even presuming the use of ceramic sockets) - it'll certainly put a damper on your overclocking.
When it comes to audio and computers, the best solutions are high-end external A/D/A converters- the kind that support multiple sample rate options (the higher the better). If you want tube "warmth," you're not going to get it from one measly, underpowered preamp tube; you'll need a good tube *power amplifier* - not for loudness, but to provide more headroom before distortion sets in. These are about the size of 4U rack units and start at $3000 a pop....check www.audiogon.com for some listings
More useful would be native support for super-high audio resolution formats like SACD; with over 100KHz frequency range it eliminates a lot of the audio artifacts present in 44.1KHz (current CD) audio, reproducing transient highs with exceptional fidelity, bringing back a lot of the "air" missing from consumer digital recordings. That and multi-channel ADAT Lightpipe i/o.....
>Most tubes are going to require abot 16,000 volts to the grid
Wrong, that is the voltage enough for arcing
and kill most living creature nearby.
In addition, it is the plate(anode)
needs high voltage(Preamp tubes 80-250V,
output tubes 200~500V). Grid always needed low voltage(2V ~100V inmost case). Anything needs
more than six thousand volts will be as large
as a street lamp, and rated to few hundred Watts.
This isn't evidence, per say, but as a semi-serious guitar player I can tell you that solid state guitar amps tend to sound harsh and sterile, while tube amps have a warmer sound to them. Modern effects processing can simulate tube amps quite well, though. I've never heard of anybody prefering a tube amp in their home stereo.
The math of this is simple - and applies to RF as well as AF. Take two of the signals in the systemm and approximate them for as sin waves. The nonlinearity can be modeled as a power series, so you have terms of the form:
f(a,b) = A*(a + b) + B*(a + b)^2 + C*(a + b)^3...
Substitute
a=sin(w1*t+phi)
b=sin(w2*t)
And do the trig and you can see that you end up with all sorts of neat frequencies such as
w1-w2, 2*w1-w2, etc.
Now, instead of f(a,b), imagine f(a,b,c,d,e,f,g...)_ and you can see the mess that intermodulation makes. It basically mixes (in the frequency domain) all of the signals AND all of their harmonics in all possible combinations!Tube amplifiers *do* sound different because their distortion curves are different than solid state amps. Why audio "purists" prefer one distortion curve to another is what I don't understand. What I want is minimal distortion overall!
But then, audiophiles also buy gigantic cables because they imagine that their speakers will sound better attached to them... etc.
Technical note: The coefficients on the various terms of the power series tend to go down with the order of the term. And, some configurations approximately cancel out all odd or even terms.
The only good weather is bad weather.
Dude, probably about 50% of all new desktop/server/etc. computers have a watchdog timer in them these days. Every new Intel chipset has one including the 845E that this motherboard uses. Some of VIA's chipsets have one. It's really hardly any work at all to put a watchdog into a chipset.
This board is about as useful to the embedded market as a 440hp straight-8 engine would be to a compact car manufacturer.
Why would they go to so much trouble as to put tubes on a motherboard for quality audio output then use the super crappy Realtek ALC650 AC'97 CODEC. Maybe their engineers know something I dont, but that was a big dissapointement when I saw it.
Tis better to be silent and thought a fool, than to open your mouth and remove all doubt --Abraham Lincoln
> high quality audio can only be reproduced outside the electrically noisy environment inside a PC case
Not strictly true--just use adequate RF sheilding. I use my PC for everything, including sound that would even be pleasing to audiophiles who didn't know where it was coming from. I use a modified high-end soundcard sheilded all around down to the sides of the PCI slot, and I've made a DIY Corda-type headphone amp (thanks, Head-Fi.org and Headwize.com!)inside a sheilded drive-bay box. Nothing is truly "external" to the PC, though it may as well be because the effect of the sheilding is the same.
RF sheilding and Faraday cages, people! It *can* be done, with a lot of elbow grease.
Chasing Amy
(We all chase Amy...)
"The more corrupt the state, the more numerous the laws"-Tacitus
I own an Antique Sound Labs MG-SI15DT stereo tube amp (2x KT88 and 2x 12AX7).
When I got it from a friend it had some nice Svetlana KT88 tubes which had a pretty hazy blue glow inside. So pretty.
Well... I was cleaning off stuff in my room one day. And I was using windex. I guess I didnt wait too long before I had switched off my amp before I wiped stuff down because I heard a *crack*.
Anyone ever set down a hot flask on a cold counter in science class?
Well, I turned on my amp and a lighting storm was going off inside that tube! And it made a horrible noise. Freaky thing was my PC was turned on about 10 feet away and when I turned on my amp my computer started beeping nonstop and it froze up until I turned off my amp again.
Some sort of freaky radiation.
Anyway, with a crack in the glass your vacuum tube ceases to be a vacuum tube.
I reccomend against water-cooling very strongly.
Very true. And there's a great story about it. Bob Carver, the amplifier designer, once took one of the much-touted High End tube amps into a test lab and characterized its transfer function. He then built a transistor amp designed to match the transfer function of the tube amp. In blind testing, listeners, even fanatical High End types, couldn't tell the difference.
It didn't sell.
So, partly as a joke, he designed the Carver Silver 7, the most overdesigned tube amplifier ever built. $25,000. All tube. Separate power supply, preamp, and power stage chassis. For each channel. Everything chrome-plated.
It sold. Got great reviews. "Amplifier of the Decade" from The Absolute Sound. Carver must have laughed all the way to the bank.
Genuinely curious: what's not solid state about a tube amplifier?
Patrick Doyle
I mod down every jackass who puts his moderation policy in his sig. Oh, wait a sec....
Water Cooled Tubes are in many high power modern RF transmitters ... I have yet to see a solid state high power AM transmitter. Semiconductors can just not take the power load.
... and was in 1995.
... amazing
Water cooled tubes are designed and built to be water cooled. When I did college radio we had an Old Harris transmitter that use to melt the tubes on us (as in the tube would come out as a glob of glass). We replaced it with a prototype first generation Harris Solid State FM transmitter
Check out Harris for more information on high end RF systems. Hmmm... looks like they do have solid state high power AM transmitters now
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