Need schematic for a 100 megawatt audio amplifier

Phil Hobbs wrote in news: snipped-for-privacy@supernews.com:

Back from your future.

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DecadentLinuxUserNumeroUno
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Phil Hobbs wrote in news:psbrhf $ckl$ snipped-for-privacy@dont-email.me:

50%

Ahhh... to say.. impinge a tiny burn on a cornea or lens, as opposed to punching a hole right through it and the retina/eyeball behind it.

Reply to
DecadentLinuxUserNumeroUno

snipped-for-privacy@notreal.com wrote in news: snipped-for-privacy@4ax.com:

Mega skipped.

What dB amount does it take to make a sound "sound" twice as loud to a human?

(it is an easy question).

Perhaps amps of this level should be measured in decabels. (DaB)

That'll make the weed folks happier.

Reply to
DecadentLinuxUserNumeroUno

Guilty as charged:

14,600 hits and increasing.

computer = a person who makes calculations, especially with a calculating machine.

computah = a machine that computes.

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Jeff Liebermann     jeffl@cruzio.com 
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Jeff Liebermann

Did you ever see the 5 ft woofer the built by the guys on Myth Buster?. They connected it to a an automobile driveshaft with an eccentric arm. Starts at about 1:53.

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Reply to
amdx

Some details on the sound system:

8 pages.
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Jeff Liebermann     jeffl@cruzio.com 
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Reply to
Jeff Liebermann

Well, not quite a 1 megawatt system:

rating as being 400,000 watts.

The 1982 US Festival relied entirely upon truck-mounted generators for its power source. For 1983, special power lines were brought in from a mile away, and which had been connected to the local Consolidated Edison grid. As emergency backup, a V-16 Caterpillar diesel was constantly idling, ready to drive a one million-watt generator set.

three-phase service available. "We are drawing about 425 to 540 amps per leg out of the available 800 - occasional peaks are seen to 500 during the loudest acts," he says. "We also see occasional peaks of over 500 amps on the neutral..."

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Jeff Liebermann     jeffl@cruzio.com 
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Reply to
Jeff Liebermann

Some feminists might kill me, but "computer" originally referred to educated unmarried women (spinsters) that were employed by astronomers to perform routine calculations.

Often this working relationship ended up so that the astronomer married his "computer", often a win-win situation for both.

Reply to
upsidedown

Not just astronomers. Physicists used more than a few "computers" on the Manhattan project. Bletchley Park had one or two, also. Before that, there was big business in artillery tables.

Reply to
krw

Charles Babbage was a human computer, one of a couple of dozen (but not women) who were paid to calculate navigational tables, log tables, astronomical ephemera, etc. The experience was what motivated the Difference Engine.

There's a good write-up on this in James Gleick's "The Information". Highly recommended.

Clifford Heath.

Reply to
Clifford Heath

by far, most of the power is in the bass drum and guitar below 100 Hz.

Take those away and you need 10 to 15 dB less.

m
Reply to
makolber

Ummm, maybe not "impressed", but I'd bet they'd be "blown away" - literally!

In a more practical vein, let's see, the biggest tubes I know about are something like the 4CX100,000, so you'd need to parallel something like

1000 of these tubes to deliver that power. These tubes cost something like $50,000 or maybe $100K each, so that's 100 Million right there. The output transformer would be the size of a utility substation transformer, but wound with Litz wire, so you'd have to radically up the cost. It would have a HELL of a turns ratio, for 18KV on the plates and 8 Ohm output. So, the output would be bus bars several feet square, I'd think. Can't imagine what a voice coil for that would look like.

Also, the plate cooling system would be plenty impressive.

At the National Superconducting Cyclotron Center, they run 2 big cyclotrons together, and the plate supply is 42-46 A at 18,000 V. (That's roughly 3/4 megawatt.) It certainly impresses the HELL out of me!

Jon

Reply to
Jon Elson

formatting link

says it'll do 2MW AF in class AB

Reply to
Lasse Langwadt Christensen

If the request from the OP would have appeared 25 years earlier, it would have been much cheaper to implement. Just take some ex-Radio Moscow transmitters and ex-Sovjet union jammers, apply a rectifier (envelope detector) or just use their high power AM modulator (audio) amplifiers.These would have been cheaply available just after to collapse of the Soviet Union.

Anyway, it is a stupid idea to build a huge power amplifier and then use a passive crossover to drive speakers for different frequency bands. A much better approach is to use "small" (20 MW) amplifiers to feed speakers with only one octave range. In fact horn speakers can be quite clean if you feed just one octave into properly dimensioned speaker.

If the OP wouldn't be too eager to use only tubes all the way, I would just use medium voltage (e.g. 3 kV) VFD (Variable Frequency Drives) for the lowest octaves. Just fiddle with the feedback loop frequency response, but otherwise some few megawatt VFDs are available off the shelf. for the lowest octaves.

Reply to
upsidedown

For a musician unable to sing or play any instruments Ozzy has done pretty well for himself.

Reply to
bitrex

snipped-for-privacy@notreal.com wrote in news: snipped-for-privacy@4ax.com:

From which came the ENIAC, and what we use as computers today.

The Bomb was for decrypting the Enigma, but artillery computation desires are responsible for our programming roots and our hardware device roots.

Reply to
DecadentLinuxUserNumeroUno

That makes the 100MW tube amplifier project viable, given enough funding to buy all the supporting infrastructure to go along with the expense of the hundred and thirty two 8974/X-2159 valves (tubes) required to create a class B push/pull bridge output amp with 33 paralleled tubes making up each of the four elements in the bridge output circuit to drive your

100MW rated 4.6 ohm speaker load directly.

Mind you, that still leaves you with the problem of making up a bi-polar

+/-11KVdc 4.6KA HT supply and arranging a suitable connection to the grid

- 33 or 66KV to 11KV three phase 200MVA transformer anyone? :-)

TBH, this looks like a project requiring the services of the "Planetary Engineering Corp."(tm) (Motto: "You give us the job and we'll do the tools.")

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Johnny B Good
Reply to
Johnny B Good

There are some thousands-of-PSI multi-horsepower hydraulic servo valves that get into the hundreds of Hz. Hydraulic bass drivers?

I'm always impressed by big hydraulics. They move mountains, usually with reversed mechanical advantage. But my knees work with reversed mechanical advantage; if I lift a hundred pounds, my muscles must be pulling tons.

I wonder why so many guys fanticize about being rock stars. Sounds dreadful to me.

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John Larkin         Highland Technology, Inc 
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Reply to
John Larkin

The interesting question is, how to make a 100 MW speaker (not just PMPO :-). I guess you could have to use tubing for the voice coil and run liquid nitrogen or helium through the coil to dissipate the heat.

In order to avoid the output transformer, one would have to minimize the amplifier output impedance but still need a very high impedance speaker. You can get the output impedance low e.g. with parallel connected triodes.

If you are forced to use multiple speakers, put them in series (with some mutual resonance issues). Old OTL stages might need 1000 ohm speakers, so it would be easy to obtain the needed load impedance.

That is the easy part. Even quite large power plant generators have only 5-20 kV output voltages so a 10/400 kV transformer is needed to feed the national grid. Look for a dismantled coal fired power plant and run the transformer in reverse directly from the 400 kV national grid.

Reply to
upsidedown

ENIAC was originally just a manually reprogrammable calculator, only much later it was capable of execute stored programs.

This was also just a preprogrammed special purpose calculator.

Reply to
upsidedown

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