Slashdot Mirror

← Back to Stories (view on slashdot.org)

AOpen Debuts The Funniest Motherboard Ever

Posted by chrisd on from the if-this-is-real-i-will-buy-it dept.

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.

51 of 473 comments (clear)

  1. Oh that's what I need... by spoco2 · · Score: 4, Funny

    More heat in my PC Box... that's a top idea. In fact, along with a couple of valves, let's throw in a few radiator elements, then you could have a PC case that you can cook mashmallows on.... mmmm, sweet, sticky goodness.

    1. Re:Oh that's what I need... by squarefish · · Score: 4, Funny

      it's only a matter of time before some mod bastard figures out how to water cool the tube!

      --
      Creationists are a lot like zombies. Slow, but powerful and numerous. And they all want to eat our brains.
    2. Re:Oh that's what I need... by Phork · · Score: 5, Informative

      umm, there are water cooled tubes, uasualy they occur in RF amps, some older FmM broadcast stations used water cooled tubes in their finals. Water cooling a tube will let it work at a higher current than it is rated for. Basically the water cooling is to keep it from getting any hotter than it is supposed to get. The water cooling doesnt take it down to 50 deg F, it keeps it at the ideal operating temperature.

      --
      -- free as in swatantryam - not soujanyam.
    3. Re:Oh that's what I need... by HerringFlavoredFowl · · Score: 3, Interesting

      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.

      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 ... and was in 1995.

      Check out Harris for more information on high end RF systems. Hmmm... looks like they do have solid state high power AM transmitters now ... amazing

      --
      TastesLikeHerringFlavoredChicken
  2. My dad says... by ColGraff · · Score: 4, Insightful

    My dad claims that some people like the sound of vacuum tube amps, so maybe this isn't nuts. But how do they deal with unfortunate tendency of vacuum tubes to burn out?

    --
    I'm the stranger...posting to /.
    1. Re:My dad says... by Russ+Steffen · · Score: 3, Insightful

      Yeah, but tubes don't automatically mean better sound. Junk is junk with tubes or without. There are plenty of tube amps that sound like crap.

    2. Re:My dad says... by RadioheadKid · · Score: 3, Informative

      Most classical concert halls use tube amplifiers.

      As someone who has worked in the sound re-inforcement business, yes tube amps sound great, audio-philes love them, but well designed transitor amps can sound great too, and are much more practical, power efficent, smaller and cooler (temperature) I'd like to see some evidence to back up your vague statement.

      --
      "Karma can only be portioned out by the cosmos." -Homer Simpson
    3. Re:My dad says... by ShinGouki · · Score: 3, Informative

      same way you deal with tubes in amps when they burn out. simple 3-step process:

      1) buy new tube
      2) remove old tube
      3) insert new tube

      entire operation takes about 30 minutes (assuming you live 10 minutes from a music store with tubes ;P)

      i've got an ampeg bass head (1200 watts (!)) that i can re-tube completely in about 10 minutes total...not really that hard an operation :)

      --
      -dk
      Dream with the feathers of angels stuffed beneath your head.
    4. Re:My dad says... by norton_I · · Score: 5, Informative

      Well, there is a difference between a guitar amp and a stereo amp. For a guitar, the amp is really part of the instrument. Tube amps definately do mess with the sound, but the player desires that to get the sound they want.

      For stereo use, the goal of the amp is (or should be) to reproduce with the highest fidelity possible the sound as recorded. There, while tube amps tend to be better than "cheap" solid state amps, a high end SS amp is at least as good as a high end tube amp.

      I do know people, however, who prefer tubes on their stereo for whatever reason (mostly snobbery, IMHO). A lot of audiophile companies make ones with tube pre-amps and a SS final stage and/or all tubes. I haven't found these systems to sound particularly better than some high end SS amps.

    5. Re:My dad says... by phliar · · Score: 3, Informative
      And my dad says tubes suck, smoke signals made by an authentic wool blanket and damp mesquite is the only way to go. I bet my dad can beat up your dad.
      Most classical concert halls use tube amplifiers.
      Classical concert halls use no amplification -- what you kids would call "unplugged." (I am a musician. I also have season tickets to the San Francisco Symphony.)

      You can design a solid-state amplifier that has exactly the same distortion and non-linearities of tube amps (but why?) -- that's not good enough for golden-ear audiophiles though. They'd rather listen to their "Test LP" on their custom turntables and talk about sound-stage separation and the "special warmth" added by the special green CD markers and about how analog is obviously better than digital because what if the signal changes between those digital samples? Me, I'd prefer no distorion, and in any case I'd rather spend my time and money on music, not equipment.

      (There are a couple of reasons to use tubes, where solid state devices don't work very well: very high power applications, like broadcast radio and TV transmitters' final stage RF amplifiers; and microwave tubes, like klystrons and magnetrons.)

      --
      Unlimited growth == Cancer.
    6. Re:My dad says... by ninewands · · Score: 3, Insightful

      Quoth the poster:

      It's common knowledge with audiophiles and professional musicians that vacuum tubes are better than solid state technologies at reproducing sound.

      It's common knowledge (among audio engineers, because MOST "audiophiles and professional musicians" don't understand the electronics involved) that a vacuum tube power amplifier operated in a push-pull configuration and biased for Class A operation produces less distortion than the designs commonly used for solid-state power amps. HOWEVER, a solid-state PA operating under the same conditions will produce just as clean an output and waste just as much power and generate as much, if not MORE heat.

      That being said, I read the tech specs on the board and find it a woefully inadequate attempt to cash in on the "coolness factor" alleged to apply to tube amps for audio.

      The tube on the mobo is a dual triode. Since it's being fronted by a stereo sound circuit, push-pull design is out of the question. It's just a straight-up dual-channel, single-ended power amplifier. This coupled with the fact that (IIRC) most multi-section tubes are directly-heated (the filament IS the cathode instead of just a heat source), indicate that improvement in perceived audio quality will be minimal at best.

      Without seeing the schematic for the amp, I can't give an opinion about it's stability, but triodes tend to be fairly susceptible to parasitic oscillations if they are operated at more than moderate power gain without HEAVY bypassing. This hefty use of capacitive filtering is what gives tube amps their reputation for "warmer sound". The fact is that a lot of the higher frequencies are bled off by the bypass capacitors.

      Class A amps typically have a plate efficiency of 35 percent or less. This, coupled with the existence of the tube's filament (heater, for the Brits among us) indicate that the tube is going to produce PRODIGIOUS amounts of heat for a minimal improvement (if any) in true audio quality.

      In short, I see it as a "gimmick" mobo.

      --
      utter rubbish
    7. Re:My dad says... by JabberWokky · · Score: 3, Insightful
      But it's not-so-common knowledge that solid state technologies can reproduce the exact same sound as tube amps. In fact, digital equipment can reproduce any sound with any quality distinguishable to human ears.

      I'm on the whole "solid state is good for music" wavelength with you, but guitar amps are kinda a special case - they are designed to be driven past the "normal" limits, and it's that breakdown in fidelity that a tube provides (and which is unique to each variant of tube) that you're after. Sure you can model the whole thing, but at a certain point, getting the sound right when you're laying down a strong bass with harsh pops with your thumb while going up and down the high treble hammering and sliding... well, it really just is easier to use an "analog" devide like a tube. It's the subilty of the extremes that tubes get right - or rather, they get it wrong, and that's what's wanted. And to 99.9% of people who listen to the music, it makes no difference whatso*ever*. But, when you're performing, you can hear the difference between your fingernails at one length and 1/16th of an inch longer, and for a musician, it's all about the tiny little details. Hell, I play almost entirely acoustic nowadays, and I like listening to the sound slowly alter in the morning in the woods as the humidity changes as the sun burns off the fog and dew. Does that mean that I care? Hell no... I just *notice* - that's what musicians do when they play. Each musician cares about different things... some *really* care about their amp sound. More power to them.

      You can hear all sorts of things in high fidelity headphones while listening to Zeppelin or the Beatles - talking off to the side, older demo tracks, etc. They were never *intended* to be played on high quality speakers with a recording as good as the master. (And if you're listening _solely_ for those little things, you're doing what someone up above pointed out - audiophiles listen to noise, not music) Kinda like how SciFi props for TV shows look like painted crap in real life - they are intended to be shown on a really fuzzy NTSC or PAL screen. Fidelity is great to a point - movie soundtracks are much more clean than most albums simply because they *know* they are going to be played in a digital theater, whereas albums are (usually) meant to be enjoyed for the music.

      Let the musicians be anal about the sound - it's your job to get laid with the music going on in the background, or blare it while driving down main street with your buddies singing along, or sob into your beer about how that guy on the jukebox is singing about how she left you, or otherwise just make part of your life. I've spent my time in darkness in a comfy chair, eyes closed, listening to good headphones... the goal is still the same: Enjoy your music.

      --
      Evan "First got laid to Grateful Dead, was listening to the Brandenburgs when I found out about 9-11, listening to Crowded House, Kill Eye right now".

      --
      "$30 for the One True Ring. $10 each additional ring!" -- JRR "Bob" Tolkien
  3. Re:w00t by TheProteus · · Score: 3, Informative

    I bet you've got a 12AX7 on there, considering they said it had a 'dual triode' tube in there. They're also some of the cheapest valves out there.

    --

    Detachment 3 Media
    Exposed, Exploited, Exploded

  4. who are they kidding? by hifizen · · Score: 5, Insightful
    As an audiophile and electrical engineer, I can tell you that no serious music (tech) lover will take this seriously. It's common knowledge amongst audiophiles that high quality audio can only be reproduced outside the electrically noisy environment inside a PC case. But more than that, audiophiles are a particular, fussy lot, and they all have their own preferences for this tube type or that.

    Who are you kidding, AOpen? Leave the high-end audio to the specialists, and leave it off your mobo!

    Websurfing done right! StumbleUpon

    1. Re:who are they kidding? by User+956 · · Score: 5, Informative

      I can tell you that no serious music (tech) lover will take this seriously.

      Most musicians are not engineers, and vice/versa. (I happen to be both, so I'll be glad to translate). Musicians are interested in sound production, and everyone else in sound REproduction. These are two totally unrelated things. A guitar amp is SUPPOSED to add distortion and tonal coloration to the signal. In fact tests for frequency response and distortion as applied to Hi-Fidelity equipment mean nothing when done on a guitar amplifier. We WANT to modify the original sound. That's exactly what the designers at Martin were doing from day 1. An acoustic guitar has a resonating chamber, a sound hole, and a front and back surface that act as diaphragms. If we could plot the frequency response of a single string played back on a good acoustic guitar, we would see all kinds of nastiness. Violins... the same thing. Saxophones... ditto. Pianos... of course. The sound quality of an instrument, what we call timbre (pronounced tam'ber) is a highly desired characteristic. It's what separates the Steinways from the Wulitzer uprights and the Martins from the Hondos, you get the idea.

      In an electric instrument, there are no resonating chambers to add flavor, so we add it with distortion instead. Distortion, the crux of the biscuit..... sometimes we want it, other times we don't. That's what always bugs engineers and audiophiles alike. When you're trying to REproduce an already distorted sound, you don't want to add any additional distortion from the amplifiers. And you certainly don't want to add transistor distortion products. Sometimes tube distortion on a clean signal is OK. What, did I just contradict myself? No way, Jose'.

      Here's the point of this whole exercise:

      TUBE AMPLIFIERS SOUND DIFFERENT FROM TRANSISTOR AMPLIFIERS PRIMARILY WHEN THEY DISTORT!

      You can see it on a o'scope, hear it with your ears, and prove it on paper, so I know it's true. And here's why: Transistors and tubes use different principles of physics for operation. Valve amps (the original name for tube amplifiers) are basically voltage driven, so when they distort, even-order harmonics are produced (2nd, 4th, 6th, etc...) while transistor amps are current driven and produce odd-order harmonics (3rd, 5th, 7th, etc....) When you look at them both on an oscilloscope, the transistor amp flattens out the waveform, while the tube amp sort of makes a triangle wave. If we look at the inherent resonances of acoustic instruments we find that things like violins make lots of even order harmonics, while things like clarinets make lots of odd order harmonics.

      Now, do we want our guitar to sound more like a violin, or a clarinet? Ah yes, the violin is much more "sweet" sounding. That's because the human brain likes and will tolerate much more even-order distortion than it will odd-order. One of the great distortion boxes in recent history is the Aphex Aural Exciter. The guys who designed this thing were marketing geniuses. The original units were sealed boxes with tamper proof hardware. They were leased to studios for final mix down. Once a few big artists like Linda Rondstat and Fleetwood Mac used and liked them, their place in audio gadgetry was assured. Of course they just use a clever method of picking out the fundamental note of say a human voice, making a little distortion, and adding it back to the original signal. This adds "warmth" or "depth" to the sound that can be, well, exciting. Our theory about odd vs. even distortion holds up because while the first units made lots of odd harmonics, several years later I remember an engineering release that hyped a new distortion circuit with increased the 2nd order distortions, while reducing the 3rd order products. Sound's very interesting doesn't it? They made a way to produce "tube" sound in a device that's basically used on vocals and strings. Again, the brain likes even-order distortion while finding odd-order somewhat irritating.

      There's some tricks to be used for making distortion. You can get transistors that are voltage driven called MOSFETS. In my opinion, they can be made to sound like tubes if properly designed. Also, once a signal is digitized, it can be made to sound like anything in theory, if the proper algorithm is applied. The problem is, they've been working on the sound of a Strat going through a Marshall for a long time. It's hard to beat the sound of a well designed tube amp, but they're beginning to learn how. Some of the new Multi-EFX boxes like the Quadraverb do an amazing job at processing a guitar. But I've found that they still need to go through a speaker to smooth out the sound. (There's additional distortion, coloration and bandwidth limiting produced by all loudspeakers)

      Now for all you guys and gals who like their transistor amps and fuzz boxes, there's nothing wrong with what you do. Sometimes odd-harmonics are needed to cut through the mix. I sometimes purposefully loop a guitar track back into an overdriven channel on my board just to "dirty" it up a little. It can make a bland lead really stand out at times. But it's just a matter of taste. I really like the even-order distorted, bandwidth limited, compressed sound of a traditional tube amp for guitar.

      But REproduction is a different story. I've got preamps that are rated in parts-per-million distortion. I tweak all my tape decks for the flattest response possible, and work hard to get the best signal-to-noise ratio possible. That's because I like the final sound to be as faithful to the original as possible.

      --
      The theory of relativity doesn't work right in Arkansas.
    2. Re:who are they kidding? by Chasing+Amy · · Score: 4, Interesting

      > 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
  5. What kind of tubes? by cporter · · Score: 3, Insightful
    The important question is, what kind of tube is it? There's only one, judging by the picture. Is it an output tube? Another question: cooling. Tubes get damn hot.

    A lot of audiophile tubes are sourced from Russian or Chinese factories. It would suck to blow the tube playing GTA3 and have to wait 12 weeks for a shipment from the far east!

    1. Re:What kind of tubes? by AJWM · · Score: 3, Informative

      From the pictures on harcop, it looks like a Russian-made Sovtek 6922 (aka E88CC aka 6DJ8). Here's the specs on a 6DJ8. Basically a dual triode like the 12AX7 but somewhat different characteristics.

      --
      -- Alastair
  6. audiophiles rejoice! by Moosifer · · Score: 5, Funny

    As a once snobbish, now reformed ex-audiophile, I cannot resist but slip back to the affected, bombastic days of my youth and exclaim "It's about freakin' time! Now when are we going to replace these markedly inferior CD-ROMs and DVD-ROMs with the gloriously mellifluous LP-ROM?"

  7. More interesting reading... by Incongruity · · Score: 3, Informative
    ArsTechnica ran a bit about this recently and they have some interesting discussion over there as well.

    You can also check out a IEEE story they link to about vacuum tubes and their uses in modern audio.

  8. New disk drive also in development for this board. by DaedalusLogic · · Score: 5, Funny

    It uses physical forms actually cut into a vinyl disk to reproduce sound. Rather than a traditional 5 1/4 disk bay it will be a USB 2.0 periperal and look something like these devices. Analog audiophiles rejoice! I play guitar and I do have to say I enjoy the sound of a classic tube amp. I wonder how odd and expensive will it be to say... Uh yeah I need a vacuum tube replacement for my computer.

    Still, could be interesting for your HTPC

  9. Re:Don't see how it's possible.... by jhines · · Score: 5, Informative

    No, that is for a CRT, standard audio tubes work on a few hundred volts.

    And it is the plate of a tube that gets the B+ high voltage, the grid regulates the current flow, and uses a modest voltage.

    A tube amplfier has 3 power supples:
    A- to power the filaments (6 or 12v AC)
    B- Hi voltage DC, in the 300 volt range
    C- Low voltage DC, to power the grid circuits

  10. Re:Ahhh... by edrugtrader · · Score: 3, Funny

    [Timeout expired]

    uh... so it the odbc connection timed out, or the time it allows to timeout expired?

    i think [ODBC fuckup] explains it much better.

    --
    MARIJUANA, SHROOMS, X: ONLINE?! - E
  11. What exactly will this tube be doing? by handsomepete · · Score: 3, Insightful

    I'm honestly asking. Would a single tube of that size after digital processing really have a major effect on sound quality? I thought the neat thing about tubes were the warmth and natural distortion they provide (in the same way as analog recording). If it has already gone through digital processing with the inherently less forgiving limits and peaks, wouldn't that actually hurt the quality? And what's the deal with that power input near the tube?

    This whole thing seems kinda skimpy on details... I hope this doesn't give Creative any ideas. The last thing we need is a PCI SB Live card with this stuff on it:
    This quality Creative Sound Blaster(tm) product requires the space of four PCI slots and a special attachment for your power supply.

  12. Why your dad says that... by fmaxwell · · Score: 5, Interesting

    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.

    1. Re:Why your dad says that... by Shelled · · Score: 3, Insightful

      Dual tubes aren't rare, and they are usually small (proper term: receiving tubes, probably from the original use in radios.)

    2. Re:Why your dad says that... by Tiroth · · Score: 3, Informative


      Two notes:

      1) many line level tube circuits do not pass through trannies. There are many reasons tube circuits do not clip "hard", but the most common one is that tubes are low gain devices, operated with low (or no) negative feedback. It is NFB that "squares up" the clipping, producing the high order (nasty) harmonics.

      2) I couldn't get to the site, but the most common tubes are dual triodes, which is quite sufficient for a stereo buffer.

    3. Re:Why your dad says that... by ncc74656 · · Score: 4, Informative
      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.

      It's probably a dual triode...a 12AX7 or something similar. 2 sections of 3 pins each (cathode, grid, plate) plus three for the heater (center-tapped so you can run it on 6V or 12V) makes 9 pins total, which was fairly common.

      (I looked for clues that this might've been an April Fool's joke, but didn't see anything to say that was the case.)

      --
      20 January 2017: the End of an Error.
    4. Re:Why your dad says that... by ncc74656 · · Score: 3, Informative
      I wonder if we can change out the stock tube (if it is a 12AX7) to maybe.. an old coke bottle sylvania or a squeeky clean russion SovTek tube :)

      The pix at HardOCP include some closeups of the firebottle...turns out it's a Sovtek 6922, an industrial-grade equivalent of the 6DJ8 twin triode (the European equivalent is ECC88). Here's a page about the 6922 and friends from what sounds like an audiophoole perspective. (The historical info is interesting, though.)

      --
      20 January 2017: the End of an Error.
  13. Well... by cirby · · Score: 5, Funny

    Compared to a high-end Pentium IV, a vacuum tube probably counts as a heat sink...

  14. Only one tube? by ktakki · · Score: 4, Interesting

    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
    1. Re:Only one tube? by blair1q · · Score: 5, Informative


      It's lower down on the page.

      The tube is a dual triode, basically two tubes in the same package. It's got one or two cathodes, likely a common heater filament, two grids and two plates. The input signals go to the grids and the output signals are taken from the plates. Common cathodes would be fine, they'd both be connected to the same supply anyway. A common filament is an advantage, because it ensures the cathode(s) get the same heat, since thermodynamics plays a significant role in tube operation.

      Answer your question?

      --Blair
      "Reading is fundamental."

  15. Analog Computing? by lostchicken · · Score: 3, Interesting

    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
  16. Does the Case Have a Window to See the Tube? by John+Hasler · · Score: 3, Funny

    "...wondering about the ability of a switched psu to properly drive a tube amplification stage..."

    Five volts will make the filament glow nicely. That's all it will take to convince the tube enthusiasts that the sound is better. No need for the tube to actually do anything.

    To be somewhat less sarcastic, a small switcher could supply 100 volts or so for the plate, or they could use one of the 12 volt tubes that were developed for car radios.

    --
    Warning: this article may contain humor, sarcasm, parody, and perhaps even irony. Read at your own risk.
  17. Tubes=Distortion by occamboy · · Score: 3, Informative

    I'm a real live electrical engineer with a degree and everything. And, I listen to lots of music, mostly classical. And I have a pretty good ear -- I can often accurately identify the conductor when listening to a piece. Here goes: Properly designed transistor amps produce distortion that is below the threshold of audibility (0.1% THD). This is really easy to accomplish -- even $200 receivers routinely do it. Tubes produce very audible distortion, and they clip softly. I'm sure that it would be pretty easy to design a circuit to reproduce this distortion and the soft clipping for the fine folks who enjoy it.

    1. Re:Tubes=Distortion by Animats · · Score: 4, Interesting
      I'm sure that it would be pretty easy to design a circuit to reproduce this distortion and the soft clipping for the fine folks who enjoy it.

      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.

  18. They're all harmonics! by Mr+Z · · Score: 5, Informative
    Absolutely, the thing is that tubes distort harmonically while solid state amps tend to distort rather dissonantly and horribly.

    Huh? They're all harmonics. Tube and certain kinds of FET (field effect transistor) based amps have a "soft limiting", so when they get close to clipping, they tend to generate even harmonics. Three of the first four even harmonics are exactly 1, 2, and 4 octaves away (2nd, 4th, and 8th harmonics), and so this form of distortion tends to be more melodic and pleasant. The 6th, 10th and so on aren't so melodic, but since the amplitude of the harmonics drops as you go to higher harmonics, you're ok.

    BJT (bipolar junction transistor) based amps (and other types of solid state amps) tend to clip rather hard. No soft-limiting, they stop right at the rails. This clipping action creates a boatload of odd harmonics. These harmonics are fairly dissonant, giving the harsh sound most people complain about.

    But they're all harmonics.

    --Joe
    --
    Program Intellivision!
    1. Re:They're all harmonics! by mesocyclone · · Score: 5, Interesting
      Errr.... harmonics at clipping are all fun and that, but only if you have one sine wave in your amplifier. With real music, you have lots of signal in there. Then, any kind of nonlinearity, whether tube or solid state, will produce intermodulation which consists of sum and difference frequencies. Intermod is infinitely annoying and the real problem with distortion in amplifiers.

      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.

    2. Re:They're all harmonics! by sigwinch · · Score: 3, Informative
      But honestly, you could be bullshitting the entire thing, and about 4 people on slashdot would know it.
      I'm one of the 4. ;-) The description of how nonlinearity causes "interesting" intermodulation in complex signals is spot on. BTW, RF engineers deal with multi-signal intermodulation all the time (cell phone base stations, cable TV amplifiers, etc.)
      Then one day, an electrical engineer came in and flat out proved to me with numbers, resistanace, etc, that you don't need anything more than 16 gauge wire for anything any amp we sold at best buy could put out into any pair of speakers we sold.
      And even if it did make a difference, heavy speaker cable should only cost a little more than jumper cables. You could even make an (almost) impedance-matched 8.3 ohm coax by putting six 50 ohm coaxes in parallel, and it still wouldn't cost as much as the ridiculous audiophile cables.
      --

      --
      Kuro5hin.org: where the good times never end. ;-)

  19. Ding Ding Ding.... by Silver222 · · Score: 3, Insightful
    We have a winner!


    The most common argument the tube lovers trot out is that the best guitar amps use them. They seem to forget that when you are listening to music, you want something that accurately reproduces the sound on your source, you don't want something that changes the source.


    "Audiophiles", flame away.

    --
    "It's not a war on drugs, it's a war on personal freedom. Keep that in mind at all times." Bill Hicks
    1. Re:Ding Ding Ding.... by scumm · · Score: 4, Insightful

      I'm not a semi-serious guitar players, I'm a pretty overly serious guitar player, and these guys are almost entirely correct.

      Since the late 70's (for the most part - some have never bothered to change) venues have tended to use solid state amplification for sound reinforcement, for the reasons listed above - more efficient power consumption, more reliable, etc.

      For guitars, tube amps just sound better. Digital modelling, etc., all try to REPRODUCE the sound of a tube amps, not best it. That's fairly telling. The reasons tube amps sound better for guitars are varied, but are mostly centered around overdriving the amp. The distortion comes on very smoothly as you roll the volume up, and responds to dynamics much better.

      For home stereo? Some of the best audiophile home stereos I've heard have been tube (mid 70's Marantz gear), and some have been transistor (late 70's Marantz gear). But tube amps are just NOT cost effective anymore, and almost all of the supposed advantages are just audiophile snobbery.

      Another problem with current tube amps is the downright sorry state of tubes. You have to search REALLY hard to find a really high quality 6L6, 12AX7, or EL34 nowadays, and those are the most common used in amplifiers. Hell, the only place to find really high quality ones, like Mullards or Telefunkens I've found is eBay. And they're expensive.

      Remember, audiophiles don't listen to music, they listen to noise, and therefore souldn't be taken seriously.

  20. Re:basic electronics by unitron · · Score: 4, Interesting
    "...a normal computer power supply could not put out the voltage needed to even warm up such a tube..."

    Well, actually it's current that heats up a tube, not voltage, although it's the voltage that shoves the current through the tube's filament. Depending upon design of the tubes filament, the voltage necessary to deliver the filament current (A+) can range from 2 Volts for some "nuvistor" itty-bitty little tubes once used in TV tuners to 35 or 50 Volts for some tubes intended for "hot chassis" radios and TVs that have the various tubes filaments in series across the AC line so that you can drop 85 Volts across a couple of tubes and use the remaining 30 or so Volts for some 6 or 12 Volt tubes.

    Most of what are known as "receiving" tubes (tubes used in radios, TVs, and audio amps, including musical instrument amps, tend to use filaments designed for 6 or 12 Volts. If all the tubes in an amp use 6 Volt filaments and/or 12 Volt center-tapped filaments, you can heat 'em all with one secondary winding on the power transformer that they're connected in parallel across (sometimes with AC to DC rectification and filtering in between the secondary and the filaments).

    Perhaps you were thinking of the tube's plate voltage (B+), which can run from 40 or 50 Volts up to several hundred. However, not only can you build a switching regulator on a motherboard to change 5 Volts DC to 3.3, but you can also include one that'll step up the voltage. It may not amount to a lot of amperage (current), but it doesn't have to. You can use a transformer on the tube's output to change high voltage, low current to low voltage, high current because power = voltage times current on both sides of that transformer, although a little bit of the power does get used up in the transformer (turns into heat). That output transformer also provides isolation from the high-voltage plate supply.

    I only saw the top-down shot where you can almost fail to notice the tube, but it looks a little bit fat to be a 12AX7 or 12AU6 size envelope. I'd go find my old RCA tube manual and try to guess what they might be using, but it's old and falling apart (just like its owner :-), and doesn't need any unnecessary mileage put on it and besides I disremember just what it's currently buried under.

    --

    I see even classic Slashdot is now pretty much unusable on dial up anymore.

  21. AC97 was Re:its a waste! by foonf · · Score: 3, Informative
    BUT useing the ac 97 codec??? i have never heard very good sound out of one of them, and i have always found it to be just that codec, if they would do it with a good audio chip, it would be much better.
    just my thoughts...

    Really, what kind of sound card do you have? If you are using your computer for high-end audio production or music composition and are talking about truly high-end sound cards, that statement has some merit, no commercial AC 97 codec can probably produce what you would consider "good sound".

    Presuming this is not the case, its probable, unless you have in fact a very obsolete or low-quality sound card, that it in fact uses an AC 97 codec similar to those used by many onboard sound interfaces. AC 97 is just a generic standard defining an interface between the sound codec (which actually produces the sound) and the controller (which attaches it to the bus, and provides DSP and synthesis functionality is some cases). Even expensive consumer sound cards like the Creative ones and the Hercules Game Theater use codecs which are AC 97 compatible. Most of the criticism of motherboard audio either has to do with the lack of features (which given that even expensive consumer sound cards don't do hardware MIDI synthesis anymore, isn't terribly relevant except for video game players) or the poor sound quality (which doesn't have to do with the AC 97 standard per se, but low quality of individual codecs and poor electrical design. None of these things are universals, I have a notebook which uses the AC 97 codec interface of its motherboard chipset, but a Crystal codec (identical to the one used by most of the CS4630 cards like the Santa Cruz, Game Theater, etc.), and produces very nice output.
    --

    "(Man) tries to live his own life as if he were telling a story. But you have to choose: live or tell." --Sartre
  22. Pictures by CaptainSuperBoy · · Score: 5, Informative

    at HardOCP

    1. Re:Pictures by n6mod · · Score: 5, Informative

      Ahh, excellent link. From the photos, we can see that the tube is a Sovtek 6922. Google tells us that thetubestore.com calls the 6922 "Sovtek's premium version of the 6DJ8." Which everyone should recognize as a dual triode. Data here tells us that it has 6.3V filaments (perfect for coexistance with any 25120's that may be required by future DRM schemes), wants 90V B+ (plate voltage) and has a max Plate Dissipation of 1.8W.

      This is a preamp tube, which is appropriate, actually. Get those nice GloFET harmonics and then feed it to some decent SandAmp for actual power.

      Interesting concept. Twisted, and I don't think I want my preamp tube in the same faraday cage as my P4, but it is interesting.

      -Z

      --
      You have violated Robot's Rules of Order and will be asked to leave the future immediately.
    2. Re:Pictures by n6mod · · Score: 4, Insightful

      For the less tube savvy out there, that means it is a preamp that can drive six channels.

      Uhh, no. It's a dual triode. That means it has two sections each of which have three electrodes. Those three electrodes are Plate, Grid, and Cathode, which map roughly to Emitter, Base, and Collector. (I think...it's been a while) Actually, I suppose Source, Gate, and Drain are more appropriate, this being a GloFET.

      In any case, there are two devices, not six, so you get two channels, not six. In fact, I'm pretty sure the 6DJ8 was designed for balanced operation, not stereo. For the less tube savvy out there, that means it was designed for one channel, not two.

      --
      You have violated Robot's Rules of Order and will be asked to leave the future immediately.
  23. Firebottle, but not Firewire? by n6mod · · Score: 3, Funny

    Now, I was almost ready to buy one of these, GloFET and all, but there's no Firewire. And since that lovely firebottle takes so much room, there are only 3 PCI slots... One for FW, One for the HD tuner, One for Gigabit, One for SCSI... oops, no more slots.

    On the flip side, I've never been much for case windows...but this board NEEDS a window!

    -Z

    --
    You have violated Robot's Rules of Order and will be asked to leave the future immediately.
  24. Re:For embedded market? by GoRK · · Score: 3, Interesting

    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.

  25. Obligatory pun jokes... by tcc · · Score: 3, Funny


    VACUUM tubes? isn't that the new name for Rambus memory that sucks even more?

    --
    --- Metamoderating abusive downgraders since my 300th post.
  26. How they came up with this idea... by evilviper · · Score: 3, Funny

    (Sitting around one day)

    Bean counter: "You know, people are only willing to pay about $6 for a soundcard. How can we get back to the good old days when people spent great gobs of money replacing high-priced disposable components?

    Engineer: Let's stick a tube in there. Everyone likes the nice fuzzy sound that comes from tubes. Hell, that's why "Turbo Bass" and equalizers are so popular.

    Bean Counter: Sounds good, as long as we get the most outlandish design, so they can't just get parts or repairs from anywhere. We want them to come back to us.

    Engineer: Got it!

    --
    Slashdot gets worse every day... Pipedot: News for nerds, without the corporate slant
  27. CD Player in BIOS by p3d0 · · Score: 3, Interesting
    Now this is cool:
    Another interesting software feature that will be shipped with the board is CD Player software. While this does not seem to be anything new, AOpen's solution can run the CD player without booting into a Windows OS. The CD Player loads immediately after the BIOS.
    --
    Patrick Doyle
    I mod down every jackass who puts his moderation policy in his sig. Oh, wait a sec....