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Discussion Starter · #1 ·
Maybe I'm missing something here, but how is it possible for amps, pro amps specifically, to put out over 2400 watts continually, when that is the most you can get out of a 20 amp line at 120 volts. Take for example the QSC PLX-3402 which is able to put out 3400 watts in bridged mono mode. Could someone of greater knowledge please explain this to me?
 

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I've got a feeling that those amps CAN'T put out that much power on a continuous basis.

You will be surprised what those proamps can do like qsc,crown and peavey ,

for further info look at the "My new amp is making me grin from ear to ear"

There is tons of info on pro amps and home theater use.
 

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Pro amps can and do deliver, but they cannot defy the laws of physics.


Perhaps Bob Lee can elaborate.
 

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I never said they defy anything all I said is that proamps are impressive.
 

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Originally Posted by louthewiz /forum/post/0


I never said they defy anything all I said is that proamps are impressive.

I have two QSC PLX-1104 pro amps and believe me they do what they say they do. Thedy have massive power and power reserves. Actually they are quite amazing if you ask me. If you can deal with some fan noise I say go for it. I love mine.
 

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Originally Posted by bbgundrum /forum/post/0


Maybe I'm missing something here, but how is it possible for amps, pro amps specifically, to put out over 2400 watts continually, when that is the most you can get out of a 20 amp line at 120 volts. Take for example the QSC PLX-3402 which is able to put out 3400 watts in bridged mono mode. Could someone of greater knowledge please explain this to me?

I see what you're asking and I agree with you...they probably don't really put out that much real power. P=IE, 2400= 20x120. In addition, amps aren't 100% efficient, there has to be some loss to heat, etc. So it has to be the funky way that manaufacturers are allowed to measure power output and I'm sure it's not consistant.
 

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They can't. There is no magic in the amps that allows them to exceed your 20A circuit. Some amps have theoretical ratings requiring other more than a 20A circuit.
 

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If one were to check the specs of the 3402, one would see that QSC says the amp will require 39A at 120V to produce 3400W bridged mono @ 4 Ohms. I don't see any claim by QSC that 3400W output is from a 15A or 20A circuit.
 

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Discussion Starter · #11 ·

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Originally Posted by whoaru99 /forum/post/0


If one were to check the specs of the 3402, one would see that QSC says the amp will require 39A at 120V to produce 3400W bridged mono @ 4 Ohms. I don't see any claim by QSC that 3400W output is from a 15A or 20A circuit.

So would it even be possible to use the full 3400 watts in a home environment? Would it be safe to run off of the 230 volt circuit?
 

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Originally Posted by bbgundrum /forum/post/0


So would it even be possible to use the full 3400 watts in a home environment? Would it be safe to run off of the 230 volt circuit?


Sure it would be possible to use that in a home environment.


Safe to run from 230? Not only safe, but probably recommended so long as the amp is configured as such.
 

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Originally Posted by bbgundrum /forum/post/0


Maybe I'm missing something here, but how is it possible for amps, pro amps specifically, to put out over 2400 watts continually, when that is the most you can get out of a 20 amp line at 120 volts. Take for example the QSC PLX-3402 which is able to put out 3400 watts in bridged mono mode. Could someone of greater knowledge please explain this to me?

Amp power ratings use continuous sine waves right at the threshold of clipping.


Fortunately, normal audio, like music or voice or soundtrack, isn't continuous, so it's safe to use the amps on 15- or 20-amp circuits even if the amp is putting out full- or near-full-power on peaks.


If you wanted to set up a test bench to do continuous full-power sine wave tests, you would need much more than a 15- or 20-ampere circuit.
 

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Discussion Starter · #15 ·

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Originally Posted by Bob Lee (QSC) /forum/post/0


Amp power ratings use continuous sine waves right at the threshold of clipping.


Fortunately, normal audio, like music or voice or soundtrack, isn't continuous, so it's safe to use the amps on 15- or 20-amp circuits even if the amp is putting out full- or near-full-power on peaks.


If you wanted to set up a test bench to do continuous full-power sine wave tests, you would need much more than a 15- or 20-ampere circuit.

So would there be any advantages to using the PLX-3402 on a 39 amp circuit instead of a 20 amp circuit when using music or a movie soundtrack and driving a subwoofer bridged at 4 ohms at full power?


Also, if run at full power driving a subwoofer using a sine wave what would happen? Would the amp clip on the 20 amp circuit before it would on the 39 amp or would your circuit breaker just cut off the current sooner? Thanks for the help!


Brennan
 

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Originally Posted by bbgundrum /forum/post/0


So would there be any advantages to using the PLX-3402 on a 39 amp circuit instead of a 20 amp circuit when using music or a movie soundtrack and driving a subwoofer bridged at 4 ohms at full power?

Brennan

Sorry, I'm not Bob, but....


No, power is power. 40A at 120V or 20A at 240V amount to 4800 watts of available mains/AC line power - either will allow the amp to develop it's full rated continuous bridged 4 Ohm output rating.


If you are strictly talking a 120V circuit, then the full continuous power of the amp is not possible on a 20A circuit.

Quote:
Originally Posted by bbgundrum /forum/post/0


Also, if run at full power driving a subwoofer using a sine wave what would happen? Would the amp clip on the 20 amp circuit before it would on the 39 amp or would your circuit breaker just cut off the current sooner? Thanks for the help!

Brennan

IMO, the (assuming 120V - 20A) circuit breaker would trip prior to the amp reaching maximum output so clipping would not really be a factor.
 

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Originally Posted by ekb /forum/post/0


So is this thing actually UL certified to run on a "39" amp circuit? I kinda doubt it. Wouldn't the power cord need to be super duper gauge and the plug some huge configuration?


Ed

Dunno if the amp is UL certified, but there are plugs and receptacles NEMA-spec'ed for 50A and 60A at 120V.
 
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