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Re: Need schematic for a 100 megawatt audio amplifier

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The word for today is "slew rate".
  And building a mechanical transducer to reproduce sound with these  
pressure levels is immpossible with our current material science.

Re: Need schematic for a 100 megawatt audio amplifier
On 11/15/18 10:31 AM, John Larkin wrote:
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Air goes nonlinear way before you get there.  Sound is basically  
adiabatic, so near the positive pressure peaks the air is hotter and the  
speed of sound correspondingly faster.  Thus the positive peaks get  
steeper and steeper as the wave propagates.  Doesn't take long to build  
up shock waves, or very nearly.

Cheers

Phil Hobbs

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Re: Need schematic for a 100 megawatt audio amplifier
On Thu, 15 Nov 2018 10:44:41 -0500, Phil Hobbs

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Sounds like a shock line, NLTL. Fast samplers use them.

Superheated shock waves would impress the crowd at the concert.


--  

John Larkin         Highland Technology, Inc
picosecond timing   precision measurement  

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Re: Need schematic for a 100 megawatt audio amplifier
On 11/15/18 2:44 PM, John Larkin wrote:
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Same idea, yeah.
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The first one would blow out their ear drums, at which point they'd have  
other things on their minds besides music, like whether it would also  
homogenize their internal organs.

The kids dancing in front of the speaker stacks would have a poor prognosis.

Cheers

Phil Hobbs

(Who used to stand down in the mosh pits of prog rock concerts in the  
mid-70s wearing ear plugs and taking photos.  He still has several  
hundred slides to prove it, not that he wants to.) :)


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Re: Need schematic for a 100 megawatt audio amplifier
On Thu, 15 Nov 2018 21:27:43 -0500, Phil Hobbs wrote:

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You'd need military grade ear-defenders for this band:


https://www.youtube.com/watch?v=-bgJC4YSNF4





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Re: Need schematic for a 100 megawatt audio amplifier
On Sun, 18 Nov 2018 18:28:09 -0000 (UTC), Cursitor Doom

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I used to work for a company that made the headphones football coaches
wear on the sidelines.  To make sure the devices worked, we needed
ambient noise measurements where the devices were to be used.  The
ambient noise on the sidelines of an Auburn/Alabama game exceeded
120dB, which can cause instant hearing loss.  We also sold equipment
to train the players to function in that environment. <boggle>

Re: Need schematic for a 100 megawatt audio amplifier
On Thursday, 15 November 2018 15:31:29 UTC, John Larkin  wrote:
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s.
ve amp to drive those. No, won't work, steam doesn't have much frequency re
sponse. Maybe use the generators of a nuke plant in amplidyne mode. You'd n
eed to make some custom ones to cover the higher frequencies if this is for
 audio - I hope it's not.
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h power drive, the compressor.
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ce all day, saying yes sir yes sir for a bit above minimum wage. Most buy i
nto the money wasted on superficial junk thing. I prefer to do something us
eful.
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1ppm is 300 people per America, 65 per UK. Certainly there's a huge mismatc
h between demand & self-assessed supply. For those that want it it's a drea
m.  


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where 'work' includes the audience surviving, no, regardless of anything el
se. P_diss alone would cook them before the band started playing.


NT

Re: Need schematic for a 100 megawatt audio amplifier
On Thu, 15 Nov 2018 07:31:20 -0800, John Larkin

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At about 180 dB, the positive peaks are at 2 bar and negative at 0
bar..

Some speakers claim 100 dB/W sensitivity at 1 m, thus 100 MW would be
80 dB higher so 180 dB would be possible, but since multiple speakers
would be needed, how would you measure the pressure at 1 m from _all_
, so not practical due to the geometry.


Re: Need schematic for a 100 megawatt audio amplifier
On Fri, 16 Nov 2018 06:31:33 +0200, snipped-for-privacy@downunder.com wrote:

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Correction: It is 194 dB
https://en.wikipedia.org/wiki/Sound_pressure#Sound_pressure_level

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Thus 100 MW is not quite enough.


Re: Need schematic for a 100 megawatt audio amplifier
On Saturday, November 10, 2018 at 11:39:41 PM UTC-5, snipped-for-privacy@myband.com wrote:
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Be sure to specify half-ounce copper on the circuit boards.

Re: Need schematic for a 100 megawatt audio amplifier
wrote:

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Is it my imagination or does this group seem to lack the ability to
design mega scale and high power devices?  Methods and construction
techniques that work so well at low power levels, do not scale well
into kilowatt or megawatt devices.  

One does not use PCB's on megawatt scale amplifiers.  One uses thick
bus bars to interconnect components.  There might be a PCB in the low
level part of the amplifier, but stages operating at over 1000 watts
need big fat conductors, physically large capacitors, heavy duty
transformers, oil bath capacitors, and high current knife switches.



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Re: Need schematic for a 100 megawatt audio amplifier

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The OP can maybe live with peak music power, or Chinese watts, which
is easier to manage on PC boards.


--  

John Larkin         Highland Technology, Inc
picosecond timing   precision measurement  

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Re: Need schematic for a 100 megawatt audio amplifier
On Saturday, 10 November 2018 23:39:41 UTC-5, snipped-for-privacy@myband.com  wrote:
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I recall the 1st US festival with 30 bands in San Bernadino started by Wozn
iak in the early 80's had a 1 Megawatt audio system. It was impressive.  

With stacked 1mx1m speakers in arrays larger than a two drive-in movie scre
ens in stereo, and it was HiFi quality.  The satellite speakers on towers h
ad perfect delay also had a water jet on a turret to cool the audience betw
een sets.  You would dry out in 5 minutes.  Unlike Woodstock, it was well-p
lanned, and well-managed.

https://en.wikipedia.org/wiki/US_Festival#Labor_Day_Weekend,_1982

Re: Need schematic for a 100 megawatt audio amplifier
On Mon, 12 Nov 2018 05:42:26 -0800 (PST), Anthony Stewart

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They had 13 years to learn the mistakes made.  No one even suspected
that Woodstock would turn out to be Woodstock.

Re: Need schematic for a 100 megawatt audio amplifier
On Mon, 12 Nov 2018 05:42:26 -0800 (PST), Anthony Stewart

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Some details on the sound system:
<https://www.prosoundweb.com/topics/sound_reinforcement/us_festival/
8 pages.

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Jeff Liebermann     snipped-for-privacy@cruzio.com
150 Felker St #D    http://www.LearnByDestroying.com
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Re: Need schematic for a 100 megawatt audio amplifier
wrote:

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Well, not quite a 1 megawatt system:
<https://www.prosoundweb.com/topics/sound_reinforcement/us_festival/2/


   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     snipped-for-privacy@cruzio.com
150 Felker St #D    http://www.LearnByDestroying.com
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Re: Need schematic for a 100 megawatt audio amplifier
On 11/12/2018 08:42 AM, Anthony Stewart wrote:
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For a musician unable to sing or play any instruments Ozzy has done  
pretty well for himself.

<
https://www.youtube.com/watch?v=yWfSyhcJyHw



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