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Technology Hardware Science

Happy 100th To The Vacuum Tube 431

williamw83 writes "Today, November 16, 2004 has been declared as the centennial of the birth of modern electronics by the American Vacuum Society. As the AIP Physics News Update reports, this marks 'British scientist John Ambrose Fleming's 1904 invention of the first practical electronic device. Known as the thermionic diode, this first simple vacuum tube, containing only two electrodes, could be used to convert an alternating current (AC) to a direct current (DC).' Today's celebration takes place as part of the AVS's 51st Annual Symposium & Exhibition in Anaheim, CA. Being a guitar player myself, I've come to truly appreciate the technology of the vacuum tube every time I crank up my amplifier. This 100-year-old grandfather of electronics, used by musicians and audiophiles across the world, has proven that profound advances in technology do not always render old technologies obsolete."
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Happy 100th To The Vacuum Tube

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  • Relays (Score:5, Insightful)

    by spike hay ( 534165 ) <blu_ice&violate,me,uk> on Monday November 15, 2004 @10:01PM (#10826484) Homepage
    Vacuum tubes, as big as they were, were a huge improvement of the mechanical relay-powered early computers.
  • by Roguelazer ( 606927 ) <Roguelazer@NospAm.gmail.com> on Monday November 15, 2004 @10:01PM (#10826485) Homepage Journal
    Yes, amplifiers are definitely the most important uses of vacuum tubes. I can't think of a single more important use in all of history that I would put down on the article had I written it...
    • *mmm* Marshall amps cranked to 11.
      • umm.. that's funny, people. or is Spinal Tap on the do not watch list here at slashdot?

        and i agree.. nothing like a warm, over driven glowing tube. i prefer fender, though.
    • Re:Amplifiers... (Score:2, Redundant)

      by GrpA ( 691294 )
      Because CRTs obviously aren't an important use of a very LARGE vacuum tube for us geeks now are they???? Let alone people who watched TV's long before plasma sets were available...
    • Re:Amplifiers... (Score:3, Interesting)

      by nate nice ( 672391 )
      I think he is referring to the fact that amplifiers are one technology that is better by the use of tubes, over the transistor, to this day. Anyone who plays guitar, for instance, knows the warmth and crunch a tube delivers is generally superior than that of a transistor.

      Can you name a more widely used application of tubes now days?
      • Can you name a more widely used application of tubes now days?

        Practically all high power radio transmitters use vacuum tubes.

        All your atom smashers use klystrons and their kin to goose those particles along.

        As others have pointed out, most computer monitors are *still* vacuum tube devices ... although that status is now eroding rapidly.

      • Re:Amplifiers... (Score:5, Informative)

        by calidoscope ( 312571 ) on Monday November 15, 2004 @11:23PM (#10826944)
        Can you name a more widely used application of tubes now days?

        High power RF amplifiers. Tubes have several advantages here, better high frequency response, can run a LOT hotter and are typically more electrically rugged (i.e. a tube can recover from an arc).

      • Re:Amplifiers... (Score:3, Interesting)

        by ncc74656 ( 45571 ) *
        Can you name a more widely used application of tubes now days [than guitar amps]?

        How about the microwave in your kitchen? It uses a magnetron to produce the RF that heats up your leftover pizza. There's probably not a kitchen in the country that doesn't have one.

    • AT&T's amplifying vacuum is the reason that radios work/worked as long range as they do/did. It is the reason that ship-to-shore communications worked. It is a large part of the start of broadcast media. It happened before TVs, the CRT is a special tube and was developed MUCH later. Without amplifying vacuums driving radio, there wouldn't have been as big of a 'drive' for TV.
    • Re:Amplifiers... (Score:5, Insightful)

      by Wouter Van Hemel ( 411877 ) on Monday November 15, 2004 @11:01PM (#10826848) Homepage
      Clearly, you don't play guitar, or you would know that the raw, warm sound of a guitar crying through a tube amp close to meltdown is as sweet a sound as a woman close to orgasm.

      But please, PLEASE, do tell us about those other undoubtedly equally interesting applications you had in mind. ;)
      • Re:Amplifiers... (Score:3, Informative)

        by nolife ( 233813 )
        I believe the generally technical accepted reason for the "raw warm sound" is:

        Tube amplifiers have much more total harmonic distortion when compared to a typical transistorized amplifier but, the distortion generated by tube amps is even order harmonic distortion and much more tolerable by the ear then the odd order distortion created by transistor circuits.
        2% of even order harmonics is typically not noticed or considered displeasing by many people but 0.5% of odd harmonics is. You can get much lower then
  • FireBottles rule... (Score:4, Interesting)

    by CptTripps ( 196901 ) on Monday November 15, 2004 @10:02PM (#10826498) Homepage
    It's a shame that more audio electronics don't use tubes. the warm sound simply can't be beat...

    It'll be a shameless plug, but here are some pics of some REAL nice tubes in action...

    http://www.firebottles.com/

    Enjoy...
    • The vacuum tube sound,
      Warming to the ears and puts
      Solid state to shame.

      Yes old technology at its best, but there is a price to pay for quality. Until I can afford such amps of vacuum tubey goodness, I will have to settle for my current amp. Which sounds pretty good. (Well pretty darn goo for my system) The tube amp upgrade would require me to upgrade just about everything to get the ooh so sweet sound.
    • Oh stop (Score:2, Funny)

      by Gothmolly ( 148874 )
      "warm" sound - let me guess, for the times when you MUST listen to a CD, you put green marker on the outside to reduce jitter? Are you a gentoo user too? This just just more Rice [funroll-loops.org]
  • Who cares? (Score:5, Funny)

    by Lobo ( 10944 ) on Monday November 15, 2004 @10:02PM (#10826499) Homepage
    Vacuums suck!
  • PC World side-note (Score:2, Interesting)

    by PMJ2kx ( 828679 )
    In the December 2k2 PC World mag (page 88), they had a preview of AOPEN's AX4B-533 Tube board. Aparently, the sound card had an integrated vacuum tube for quality sound, and it's supposed to be great, but I never bought one myself. Has anybody else?
  • I hope the demand for guitar amplifier tubes keeps manufacturing going for a few more years.
    I for one, welcome my EL34 and 12AX7 overlords that glow red hot inside my Marshall.

  • Posted by timothy on Monday November 15, @09:59PM

    Couldn't wait another 2 hours, could you?

  • by Dancin_Santa ( 265275 ) <DancinSanta@gmail.com> on Monday November 15, 2004 @10:07PM (#10826531) Journal
    What with the current crop of professional mixers so intent on recording at levels well above the maximum range of the media the music is written onto, it hardly seems necessary to invest in such outdated devices in an effort to recapture that unique sound of yesteryear.
    • I think people going for hardware that plays the sound of yesteryear are probably going to be playing the *sounds* of yesteryear as well.

      Living in the past has never been more stylish.
  • ...sounds like my old Vox AC30 with JJ/Tesla vacuum tubes. Thank you Slovakia or whichever former bloc country makes these things. And thank you too the enviroment, which lets yourself be destroyed by the hugely enviromentally unfriendly production practices in place to makes these things.
  • by InfoVore ( 98438 ) on Monday November 15, 2004 @10:08PM (#10826539) Homepage
    here [joyoftech.com]

    - I.V.
  • by maeka ( 518272 ) on Monday November 15, 2004 @10:08PM (#10826542) Journal
    This 100-year-old grandfather of electronics, used by musicians and audiophiles across the world...

    As a musician I resent being in the same sentence as an audiophile.
    • Re:Please don't! (Score:3, Insightful)

      by a whoabot ( 706122 )
      This I agree with. People obsessed with the fidelity don't even listen to the music. They always say, "I just want to hear the music like it's supposed be heard!" But total fidelity make the music disappear. Like a collector. What he collects disappears into the collection, which all follows a model inside his head.
    • Re:Please don't! (Score:3, Insightful)

      by swordgeek ( 112599 )
      Heh. Agreed. Tubes are excellent at producing sound, but not necessarily great at reproducing it.
  • by Jrod5000 at RPI ( 229934 ) on Monday November 15, 2004 @10:09PM (#10826543)
    i find it interesting that vacuum tubes are considered _modern_ electronics. wouldn't the transistor be a better first milestone in modern electronics? what sort of electronics existed before 1904 anyway?? i would suggest that vacuum tubes marked the beginning of electronics in general.
    • Well, by modern I think they mean signal processing, prior to the vacuum tube what type of electronics did we have? anything better than a carbon arc lamp and a few side show effects.
    • i find it interesting that vacuum tubes are considered _modern_ electronics. wouldn't the transistor be a better first milestone in modern electronics

      You couldn't have the transistor unless you had a pair of diodes.

      what sort of electronics existed before 1904 anyway??

      Just a few of trivial things like the telegraph, telephone, and radio.
    • by steve_l ( 109732 )
      yes, tubes were the core of electronics.

      I have my grandfathers 1938 AM radio; all valves inside. It still works. No PCB; just valve sockets hand wired, thread to go from the tuning dial to the variable capacitor. Its fascinating that a piece of tech from nearly 70 years ago still powers up (and that after 30 years in an attic).

      Some amusing features of it

      -you have to manually set the voltage of AC power to one of three taps: 240, 230 or 220. (this is the UK BTW). Power must have been less consistent in th
  • I love my tubes!!! (Score:2, Interesting)

    by al701 ( 617447 )
    I can't believe the tech is 100yrs old. I knew it was old but 100. For those that say tubes are dated clearly havn't listened to "good" stereo equipment. Might I suggest Audiogon [audiogon.com].
  • by Malluck ( 413074 ) on Monday November 15, 2004 @10:11PM (#10826558)
    Lets not forget the single largest use of vacuum tubes today, the CRT (cathod ray tube). There in your old TVs and moniters.

    Also every radio station and high power transmission you listen to is transmitted by large vacuum tubes. Silicon may never be able to replace these 10KW+ monsters.
  • Aah, vacuum tubes (Score:5, Interesting)

    by bigberk ( 547360 ) <bigberk@users.pc9.org> on Monday November 15, 2004 @10:14PM (#10826576)
    Our only hope in case of an EMP (/nuclear). Vacuum tubes may be ugly and power hungry, but they are much more likely to withstand huge electromagnetic pulses (malicious or otherwise).
    • Our only hope in case of an EMP (/nuclear). Vacuum tubes may be ugly and power hungry, but they are much more likely to withstand huge electromagnetic pulses (malicious or otherwise). ...but far less likely to survive a fall of 6 inches.
      • ...but far less likely to survive a fall of 6 inches.

        Obviously you haven't read up on the history of the proximity fuze. Deak Parsons and team found out how to make a vacuum tube survive in the nose of a 5 inch naval shell - with initial acceleration of several thousands g's.

    • >Our only hope in case of an EMP (/nuclear). Vacuum tubes may be ugly and power hungry, but they are much more likely to withstand huge electromagnetic pulses (malicious or otherwise).

      Widely believed, but when the ARRL did tests in military EMP simulators they found the opposite. Put a high surge current into a low input impedance solid state device, and it goes "oh, another current". Put the same current into a high input impedance vacuum tube device and you get an enormous peak voltage.

      More important
  • Posted by timothy on 11-15-04 21:59
    from the vacuums-don't-suck dept.
    williamw83 writes "Today, November 16, 2004 has been declared as the centennial of the birth of modern electronics by the American Vacuum Society.

    Timmy couldn't have waited another 2 hours to post this?
  • by PotatoHead ( 12771 ) * <doug@NoSpAM.opengeek.org> on Monday November 15, 2004 @10:15PM (#10826583) Homepage Journal
    cool.

    They glow. Seriously, that's why I think they are cool. Anything that warms up has a nice feel to it. Old radios sound very interesting as they come to life. After the click of the power switch, first nothing, then a low hum that is replaced by subtle noise as it drops, then finally the audio creeps into the foreground. Soon after comes the smell of dust burning..

    I had a chance to build some vacuum tube projects in the late 80s. (We had lots of tubes and nothing else to do.) Made a power supply for the older speakers that featured electromagnets on the back to revive an old tube radio.

    Tubes forever!
  • by Thai-Pan ( 414112 ) on Monday November 15, 2004 @10:20PM (#10826615) Journal
    As a guitarist who is a tube nut (currently own a Mesa Mark IV and a Rivera TBR-1SL), I'm a bit disappointed to see that nobody has improved the vacuum tube at all since it was abandoned in the mainstream for the solid state transistor. It's a well known fact that guitar amplifiers produce more pleasing sounds when the tubes run hot, but amps which are known for running the tubes hot (such as the Vox AC30) are also known for blowing tubes. Why haven't we made tempered glass (Pyrex?) tubes built to run at higher temperaturesr. Why haven't we applied newer technologies to produce better tubes? It also seems odd to me that tubes made today don't seem to last any longer than tubes made 50 years ago.
    • Because for everyone of you, there are 23 of me; a solid-state guitarist all the way.

      That being said; I'm sure you can convince some rich audiophiles/venture capitalists to plunk down some money to finance a pyrex-like tube.
      You would be the king of a niche industry.
    • I think they already have - ever see a modern day vacuum tube used in the PA stage of a RF amplifier? Aluminum and ceramic tetrodes, cooling fins - casually looking at it you probably wouldn't even know it was a tube.

      Here's a 15000 watt 4CX15000 [coutant.org] show me a transistor that can do that.
    • Not much money in it (Score:4, Interesting)

      by Sycraft-fu ( 314770 ) on Monday November 15, 2004 @11:09PM (#10826884)
      More money is made in selling replacement tubes :) Seriously, most tube people are to drop the cash on it. Those that aren't switch to transistor. It used to be you couldn't get that nice warm sound with transistors, they just don't distort the sound in teh same way as tubes. Well, DSPs have changed all that. You can get quite a large amount of signal processing for quite a small amount of silicon. The tube modeling amps are really quite good these days.

      As an example of one that just rocks (albeit impractical for stage), check out Native Instrument's Guitar Rig. It's software for the PC. Unprocessed (as in no amp, mic or anything) electric guitar goes in, great sound comes out. Clean, distorted, whatever you want. Build a virtual rack of amps, EQs, speakers, mics, etc and it models them to a high degree of accuracy. It's quite impressive.

      So for most people concerned about money, something that models a tube amp is good enough. The purists, well they'll spend the money on the tubes.

      Also, though I'm not 100% certian, I think that part of what gives that nice warm fuzz is running a tube up past it's limit. Unlike transistors, which are basically linear to a point then just stop pasisng more power, tubes are fairly linear then start curving off more and more, and increasing in distortion. So to get that real warm sound, you run them past their linear phase.

      So if you built a tube with better characteristics, stands to reason you'd just have to drive it that much harder to get what you want. As I said, not sure on this, but I'm guessing it's part of the reason.
      • by N3Bruce ( 154308 ) <n3bruce@gmail. c o m> on Tuesday November 16, 2004 @12:17AM (#10827200) Journal
        In all seriousness, the tube market today is relying on the sale of tubes that for the most part were made 50 years ago, or with tubes imported from the former Soviet Union or China. The Soviet/Chinese tubes have become a mainstay for hams running 1KW class linear amplifiers, and there is a steady market for types such as 4CX500, 3-500Z, and so on.

        Sadly, for many antique radio restorers, the prices and lack of availability of certain tube types keep many promising projects on the shelves, and many of the radios that used those tubes are usually found stripped of them. A late '20s or early '30s console will almost always have the type 45 tubes stripped out.

        At the same time, just about anyone who has acquired box lots of tubes will tell you that 90 percent of the tubes will never get used. A lot of these tubes were manufactured as replacements in 1960s era TV sets, and in a way were the first "integrated circuits", but have little use outside these roles. They were made by the tens of millions, but were made obsolete by the quick adoption of solid state circuitry in the 1970s. Few people collect or maintain 1960s era TV sets, but the old tubes stay around just as the 1mb memory sticks collect in many modern day geeks junk boxes. Other tubes, such as the combinations used in many '40s and '50s radios are available in adequate supply, either with tube vendors at hamfests or online for the forseeable future, or could be pirated from undesirable radios.

        It is just too expensive to do small scale tube production to satisfy the needs of a few thousand antique radio collectors and amplifier restorers. Inquiries were actually made to one of the Russian manufacturers to start producing new Type 45 or similar tubes. A run of a few thousand would satisfy the needs of collectors for years, but the unit costs are as high or higher than buying New Old Stock where it can be found.

        I have been somewhat inactive at the restoration game for a few years, but I remember when a major antique radio club looked into having one of the Russian or Eastern European manufacturers build some new highly sought after types, the combination of minimum quantities and unit cost would have risked tens of thousands of dollars, for a product that has a very limited market. Perhaps the ability to sell to a worldwide market easily, ala eBay might make it feasible today, but it would still be a risky proposition.

        There are other tube types that would be welcome if they could be produced economically with a limited run, such as 7360, 1L6, and probably a couple of dozen other types. Perhaps a modern cottage industry could pick up the slack.
  • by Bilestoad ( 60385 ) on Monday November 15, 2004 @10:23PM (#10826642)
    Actually solid-state does render vacuum tubes obsolete, to the rational mind. Once you've admitted that the sound you really like just involves lots of second order distortion it's no big deal to make a processor using opamps or discrete transistors to add that distortion to a reliable, efficient, cheap amplifier. As many manufacturers have done! Boss, Line 6, and Roland to name just 3.

    You're also forgetting that the biggest contribution to the sound comes from the cabinet, speaker and transformer. Like I say, the valve just adds some nice distortion.

    You're not one of these people who believes in gold-plated connectors and $2500 power cables too are you?
    • by Anonymous Coward
      Pyrex glass contains traces of uranium which provides a heavy-element lattice in which the glass can form. This is what provides it with the extraordinary strength. It's also why Crystal, which is formed with lead, is very brittle but glows compared to normal glass.

      The uranium, as you know, is not stable and the excess electrons emitted when the element decays interferes with electric devices (it's also what protects the glass from breaking in the microwave. The pyrex actually heats up when nuked). So
      • by Anonymous Coward
        Normal (kitchen) Pyrex does not contain traces of uranium. Pyrex is a basic borosilicate; the additive element is boron. Certain commercial applications do add uranium to Pyrex, but these are usually identified as Uranium Pyrex.
    • Dude, you are supposed to paint the tubes with a green magic marker. Everyone know that makes them sound better.
    • No Way! Valve amps sound great and look great. They are also fun and interesting to build (unlike solid state amps). No Gold plated connectors or $2500 power cables required!

      I am in the palnning stages of new valve amp to build during short days of the winter.

    • by antiMStroll ( 664213 ) on Monday November 15, 2004 @11:04PM (#10826867)
      From the back panel of the near 50 year old McIntosh MC250 sitting on my floor:

      Total Harmonic Distortion less than 0.5% at rated power (40 watts) 20-20,000 Hz

      Intermodulation Distortion less than 0.5% at peaks twice rated power.

      Distortion at normal listening levels of under 1 watt is well below 0.1% . Point me to any auditory studies which claim this is audible. Tube preamps do much better still.

      Incidentally, the 2nd harmonic argument is generally incorrect applied to most mainstream audiophile tube components. An amplifier's harmonic envelope is determined by the linearity of the base amplifier and the amount of feedback applied. More feedback eliminates even order harmonics (that would be the second) faster than odd. It's a good bet the bulk of the MC250's distortion is odd-order.

      On the other hand, maybe I should just shut up. It was another "rational mind" who told me I could have this amp gratis almost 20 years ago. The solid state receiver and 50 watt Bryston amp I had at the time have little to no value now, this one still commands well over $1000 US on the international market. You know, you're right! Toobs do suck!

      • by mveloso ( 325617 ) on Monday November 15, 2004 @11:13PM (#10826900)
        Funny, I remember someone doing a blind test with a tube amp and a solid state amp with a bit of distortion.

        When they didn't know which was which, the group of audiophiles ranked them equally.

        When they knew which one was the tube, they rated the tube higher...even if it was the solid state amp.

        I wish I remembered where I read it. It was back in the early 90s, pre-web.
      • by Sycraft-fu ( 314770 ) on Monday November 15, 2004 @11:35PM (#10827005)
        Well, let's see. Given that I could get a used Hafler P1500 or P3000 for about 1/10th the price which has 0.2% THD at rated power (75 and 150 watts per channel in 8 ohms respectively) or a new Rotel RB-1080 for the same price with 0.03% distortion, I'm thinking solid state does look to be a bit better deal if we want to play the numbers game.

        Of course the thing is, THD is talking about the average distortion, nothing about the shape. Generally speaking, tubes are more overall and a peak down in the 1khz range or so. Transistors are generally lowers with a peak more in the 10-20khz range. Thus the distortion, at a given THD, is usually more audible on a tube, if often plesant.

        But just because a tube amp holds it's value doesn't mean it gives good bang for the buck. You can easily get cheaper, better perforing, more powerful, more rugged transistor amps.

        It's kind of like a vintage car. An orignal Model-T restored and in excellent condition will sure as hell cost more than a new Subaru WRX. However it doesn't mean it's a better car for driving around in, the WRX will outperform it in basically every way. It's the fact that the Model-T is special, not better.
        • by antiMStroll ( 664213 ) on Tuesday November 16, 2004 @12:12AM (#10827177)
          No one's playing "numbers games". You miss the point entirely, which once again is: neither amp is 'scientifically' audible at normal listening levels. The grandparent post's claim that tubes are prefered for their high second harmonic content is wrong, even at face value. Most tube amps are push-pull, a topology which cancels even harmonic distortion quite effectively.

          Your statement about distortion spectra is a funhouse mirror of the facts. Harmonic distortion is harmonically related. Transistor amps, having much higher open loop gain and therefore much higher feedback (which is how they achieve those low distortion numbers, some of the most linear simple gain devices every made are low gain 1930's direct-heated tubes) will have a harmonic distortion content shifted much higher because of it than typical tubes but it's still based on the excitation signal. Bass signals don't magically generate distortion between 10 kHz and 20 kHz. And this is far from an advantage, the least audible distortion is second harmonic. Higher odd-ordered harmonics are audible at levels much, much lower than second.

        • by Grendel Drago ( 41496 ) on Tuesday November 16, 2004 @02:37AM (#10827770) Homepage
          I gotta wonder---do I sound like this when I'm geeking out about discovering a whole nifty set of panorama-stitching tools, going on about Laplacian pyramids, control points, barrel distortion and such?

          No wonder the non-dorks I talk to get such a glazed look in their eyes when I tell them what I'm currently interested in.

          --grendel drago
    • by T-Ranger ( 10520 ) <jeffwNO@SPAMchebucto.ns.ca> on Monday November 15, 2004 @11:16PM (#10826910) Homepage

      Are you talking about sound PROduction, or sound REproduction?

      If you are talking about production, what you say is true. Electric guitars sound "better" with tube amps, because thats how they sound. The player is not "distorting" the sound, the guitar+amp is the sound. A harmon mute "distorts" a trumpet sound, but when you are trying to make that sound, kick ass.

      If you are talking about sound REproduction, bullshit. Discrete transistors distort the signal less, and you are trying to play back the recording AS CLOSE AS POSSIBLE TO HOW IT WAS RECORDED. Transistors will do that better then tubes, and have done so for decades. Tubes will fuck up the signal.

    • by Lisandro ( 799651 ) on Tuesday November 16, 2004 @12:46AM (#10827349)
      There's more to "amplifier sound" than just adding harmonics. If you like that sound, theres's a gadget called exciter that would do it for you. The distortion discussion is long and i feel, IMHO, than an amplfier that adds excessive unwanted distortion can't be called Hi-Fi to start with. But still...

      Valve amplifiers have a number of design implementation characteristics that make them desirable for audio. For starters, almost every single valve amplifier is transformer-coupled at the output, which gives it a distinctive sound "coloration". Valves have much better slew rates and open-loop freq. response than transistors, which are desirable characteristics in audio devices. And, for a number of reasons, valve amps usally drive speakers much better, resulting in, yes, better sound. Class-A amplifiers (specially the so-called "single ended ones", where just one device energizes the speaker) exhibit a similar behaviour, which is why they are usually agreed to "sound more valveish" than regular ones.
      Of course, valves have limited life, become microphonic over time and require manteinence. But that's part of the fun of it...

      The truth is, most valve amps DO sound better. It might not be by much, but the difference is appreciable, and some people are willing to pay for it. A special case is instrument amplifiers, where valves are still unmatched. If you ever played an electric guitar, you'll know.

      That being said, yes, i agree that a good set of speakers can make a bigger difference than a new amp. And the people who spend $2500 in interconnects and power cables (yes, they do) are insane, but don't think valves are obsolete. They have their place, even when in most areas transistors are more practical. For audio gear, instrument amplifiers, and power communications valve designs are still the norm. And, if you're using a CRT, you're pretty much looking at a huge device which works by the same principle as a vaccum valve.
    • Hey... (Score:3, Funny)

      by TibbonZero ( 571809 )
      I sell the gold plated connectors and $2500 speaker (and power) cables!
      www.blinkhighend.com
  • by tyman ( 831421 ) on Monday November 15, 2004 @10:24PM (#10826644) Homepage
    The Toronto Star did a front page write up [thestar.com] in their @Biz section.
  • by flyingsquid ( 813711 ) on Monday November 15, 2004 @10:26PM (#10826657)
    My professor told me how once he had a radiograph machine that wasn't working, and when he asked for an explanation, the repair technician pointed to the tube and patiently explained to him that "All the vacuum leaked out."
  • by StefanJ ( 88986 ) on Monday November 15, 2004 @10:45PM (#10826768) Homepage Journal
    The TVs my family had when I was a kid used tubes. So did my father's clunk old mono "HiFi" pre-amp/amp. They glowed and smelled neat and took forever to warm up.

    When a tube went bad, we had to go to . . . the drug store.

    There was a white-painted masonite kiosk there. It had a board on top where you could plug in a tube. There were a few different sockets. I forget how they indicated success or failure.

    The kiosk had a locked cabinet where the spares were kept. I can't imagine there were more than a couple of dozen types there, and I suspect it was a lot less than that.

    Stefan

  • We've probably dreamed staring into the glow of filaments as much as musicians.
  • Nuclear Proof? (Score:4, Informative)

    by dfn_deux ( 535506 ) * <{moc.liamg} {ta} {015nustad}> on Monday November 15, 2004 @10:48PM (#10826784) Homepage
    The best application for vacuum tubes that i've heard of is for the flight control systems in cold war era Russian Mig Fighter jets. Apparently Vaccum tubes are much more resistant to the EMP blast created from a nuclear detonation. Which means in the early stages of WWIII the Russians would still have jets in the air while American fighters would quickly realize that all the millions of dollars worth of high tech computer gadgetry that allows their planes to fly does not operate once a few chips go poof.
    Here's a link which mention this. [thefreedictionary.com]
    Apparently the model used in the Mig 21 radar system (the SC33C triode) has garnered quite a following in high end audiphile class A tube amplifiers...
  • Yes indeed, Tubes Rock [geekculture.com]!
  • Blow yer own (Score:3, Interesting)

    by -Harlequin- ( 169395 ) on Monday November 15, 2004 @10:53PM (#10826816)
    While I personally don't think tube-distorted sound is "better", ("different" is a better word - if that's what you want, fine, if someone else, such as the Rest Of The World, doesn't care for it, Deal With It :), I am quite interested in building my own tubes in order to build some electrical devices from raw materials. Caps, batteries, etc are easy. Transistors are harder than tubes, so... anyone know of any good books on making your own tubes?

  • by tie_guy_matt ( 176397 ) on Monday November 15, 2004 @10:56PM (#10826824)
    Yes vacuum tubes were invented 100 years ago, but it wasn't until much later that Howard Armstrong perfected them such that they could be used as amplifiers. I think he was certainly an un-sung hero. He perfected the vacuum tube, then he invented the super hederodyne circuit used in modern AM radios. Later he go so upset at the static and poor quality of AM that he turned around and invented FM. A great story with a tragic ending -- he ended up killing himself by jumping out of a tall building. This is of course after years of patent battles with RCA (the microsoft of their day.)
  • by the_rajah ( 749499 ) * on Monday November 15, 2004 @11:02PM (#10826850) Homepage
    I've got some tube type shortwave receivers including a Hammarlund HQ-129X ca. 1946, a Hallicrafters S-38 ca. 1946, a Collins 75A-2 ca. 1952 and a transmitter, a Heathkit DX-40, all in good working condition. Radios like this are often referred to as "Boat Anchors" [dmoz.org]

    There are quite a number of Ham radio transmitting power amplifiers from various manufacturers on the market that use tubes, too.

    73 - K9LJB

    "Do the Right Thing. It will gratify some people and astound the rest." - Mark Twain "Boat Anchors" [dmoz.org]
  • by toonerh ( 518351 ) * on Monday November 15, 2004 @11:25PM (#10826954)
    I'm surprised no one realizes nearly ever radio or TV transmitter outputting 1,000's of watts or more uses tubes, albeit ceramic tubes rather than glass ones in most cases. And this is today in late 2004. Although in the most technical sense they are "amplifiers", they aren't audio amps. The transmitter tubes often have metal fins to radiate heat and a "chimney" to air cool the tube. This technology could be adapted to "hot" guitar amps, although they would be pricey.
  • by hpa ( 7948 ) on Monday November 15, 2004 @11:36PM (#10827009) Homepage
    ... and not just for "the warm sound." They're used because they can be built arbitrarily large much easier than you can build power MOSFETs. You can build them to produce hundreds of megawatts of RF energy with a single klystron; a linear amplifier tube can easily be built to handle megawatts.

    I haven't heard of any 1.22 GW vacuum tubes, but they certainly could be built. They'd be large.
  • by earthforce_1 ( 454968 ) <earthforce_1@y a h oo.com> on Tuesday November 16, 2004 @12:22AM (#10827223) Journal
    Despite the recent improvements in LCD technology, it is easy to forget that most of you are reading this off a vaccum tube CRT. Your household microwave contains a cavity magnetron tube. The niches for tube technology are diminishing but far from dead yet.

    I have even heard of tiny tubes being etched out of silicon using the same photolithography techniques used to create other forms of nanotechnology. This is not as silly as it sounds, they could survive heat and radiation that would cook a transistor, and would be ideal in environments no solid state component could survive. (In a jet engine combustion chamber, a venus lander or on a space probe operating well inside Jupiter's radiation belts, or close to the sun)

  • This goes out to all of those that say there isn't a difference in tube amplification, and modelings of just extra 'distortion'. I offer two examples of such failures.

    As proof of this, I offer the Vox AC30HW, which I have had plenty of experience playing. Now the same company, has created a Vox Valvetronix amp or whatever crap they call it. I'd only assume that the company the manufactures the AC30 would be able to emulate it the best, however they do a terrible job. Hook up an A/B amp switch, and try to achieve similar sounds. Now push the Solid state POS to higher levels, how does it react. Try different playing dynamics, etc... Now try the same with the Vox. The vox only gets better, and the emulation, doesn't act at all like the real deal, nor sound ANYWHERE as good in depth, tone, or musical dynamics. In other words, it sounds like shit.

    Take a Cybertwin amp by Fender, and put that against a real 64 or 65 Fender Twin with great tubes in it, that has been maintained well. Not even in the same ballpark.

    So if the manufactures themselves can't even get it right, who can? I'm sure at some point it can be done, but just the A/D and D/A conversion and poor clocking on these digital amps kills it from the start.
  • by Bazman ( 4849 ) on Tuesday November 16, 2004 @05:03AM (#10828231) Journal
    In the USA these things are called 'Tubes'. In the UK we call them 'Valves'. Why?

    Well, they look like tubes, but they function as valves. And of course the people of the USA are more concerned with looks than functionality... :)

    Baz
  • by gatkinso ( 15975 ) on Tuesday November 16, 2004 @10:44AM (#10830588)
    Who knows where the combination could lead?

Algebraic symbols are used when you do not know what you are talking about. -- Philippe Schnoebelen

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