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Happy 100th To The Vacuum Tube
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."
here
- I.V.
"These laws they're passing won't even compile anymore, let alone execute." - anon
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.
My 300B mono blocks will eat anything which you can buy today.
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.
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.
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...
-*The above statement is printed entirely on recycled electrons*-
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.
Can you name a more widely used application of tubes now days?
... although that status is now eroding rapidly.
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
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).
A Shadeless room is a brighter room.
Errr... NO! Steinberg's The Grand is still a ROMPler instrument and plays back wave files, but adds stuff to them like effects.
Right now computer modellig in real-time is still way, way off into the future and what's out there sounds nothing like real acoustic instruments.
When high power semiconductors fail, you need to worry about shrapnel. When high power tubes fail, they look great on a shelf.
Fascism trolls keeping me up every night. When I starts a preachin', he HITS ME WITH HIS REICH!
Since relays are inherently switching elements as opposed to amplifier elements, they did not need resistors; the only necessary resistance is the one inherent in the relay coils themselves.
As a musician myself, I have to agree that tube amps have their own unique "tone" and haven't ever been perfectly reproduced yet by solid state gear.
Tubes are natively voltage amplifiers, bipolar (NPN and PNP) transistors are natively current amplifiers. Sure you can make circuitry to create either a voltage amplifier or a current amplifier as a system around either device, but that still doesn't change the native way in which each device performs internally. When overloaded, a tube naturally produces mostly even-order harmonics. A bipolar transistor will naturally produce both even and odd-order harmonics, but mostly odd-order... which sound very harsh.
Tube amps natively have *very* high slewing rates too, much higher than most transistor amps, except for some very recent, exotic transistor amp designs which use some very special transistors, which are finally beginning to approach the slewing rates that simple tube amps have achieved forever. This is probably the single reason why tube amps sound so much more "crisp and clear" than transistor amps have historically been able to achieve.
Really!
http://www.lindsaybks.com/bks7/finstr/
the URL links to one of several places that you can get the book Instruments of Amplification by Pete Freidrichs. The book describes how to build your own tubes, transistors and other more obscure amplifying technologies. Oldskool Geek at its best!
(Or Google for "instruments of amplification")
Note: Lindsay Publications is worth a lookaround... LOTS of obsolete-but-interesting, obscure, or otherwise hard to find tech books, generally CHEAP!
DIsclosure: I have no connection whatever with Friedrichs or Lindsay Publications!
The Fleming diode might have been the first electron tube (valve) but it was Lee De Forest who put in a control grid between the filament cathode and the anode plate and created a device that could amplify voltage, which made the whole world of useful electronics circuitry all possible. The 100th anniversity of De Forest's "Audion" triode is not until 2007.
I Only know one such book, "Instruments of Amplification" by Pete Fredrichs. It may be had from several sources, one of which is:
http://www.lindsaybks.com/bks7/finstr/
Or Google on the title
Telephone switches and relays were reliable and remanined in service for decades. Bell had a functional elecro-mechanical calculator using 450 relays with teletytpe output in 1939. Ballistic calculators built for WWII had 9000 relays, and there lies the problem. 9000 vacuum tube relays are power-hungry, hard to cool and need constant replacement.
I haven't heard of any 1.22 GW vacuum tubes, but they certainly could be built. They'd be large.
t m
Gigawatt Multibeam Klystron (GMBK)
A 2-GIGAWATT, 1-MICROSECOND, MICROWAVE SOURCE
15 feet long 15 inch diameter
http://www.slac.stanford.edu/grp/kly/muri/murid.h
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 0.5% with modern solid state amplifiers though, this reduces the total distortion and makes the sounds more accurate but for some instruments like the guitar, the even order harmonics generated by the tubes are desired.
Bad boys rape our young girls but Violet gives willingly.
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.
It was actually Major Edwin Howard Armstrong. http://wfmu.org/LCD/GreatDJ/armstrong.html
The light at the end of the tunnel is a train.
Ah, relays!
...
Pole slugs, heel-end slugs, multiple windings, opposed windings, balanced windings, serial / parallel resitance, serial / parallel capacitance, diode clamping,
All things done to the humble relay to modify operate / release characteristics and timing for use in logic circuits.
Who said 20 years in Telecomms was a waste of a life? Well, I did - just last week, in fact! But it did lead to an appreciation of some of the weird & wonderful design & engineering tricks pulled just to Make Stuff Work...
What part of "a well regulated militia" do you not understand?
A diode valve/vacuum tube allows current to travel in one direction and not the other. "Valve" seems a good name to me.
All I want is a secure system where it's easy to do anything I want. Is that too much to ask ~~ Randall Munroe
The silvery spot inside most tubes was barium, not mercury. It reacts with oxygen to form barium oxide, the white powder inside a tube that has "gone to air".
Mercury was used in some tubes, but not the ones you would find in a TV or radio set. Mostly big rectifiers, thyratrons and ignitrons used in transmitters and industrial gear.
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For audio that is... I still listen to superior vinyl records on a VTL all tube system. I hate digital but I love the iPod. At least an iPod played through tubes sounds better than through solid-state...
For over 50 years the majority of electronic devices were based on vacuum tubes. (Radio, radar, audio amplifiers, tape recorders, etc.) They reigned for just as long as transistors have today, and set the foundations for many of the major businesses that drive the 21st century: media (movies, radio, TV), computers, etc. Even today, your microwave oven contains a tube, and in all probability, so does your TV set.
has proven that profound advances in technology do not always render old technologies obsolete.
yeah, it's not obsolete, just expensive, and not as easy to come by...