Watt Meter

vizion · 11th August 2010, 11:02 PM

There was an old thread about power meters. I found this little toy that can do the job nicely.

Atlantic Quality Design, Inc., The PM-150 Audio Power Meter

Nelson Pass · 12th August 2010, 05:40 PM

Usually I only need to go up to 1 watt.

vizion · 12th August 2010, 10:33 PM

Curious, since First Watt specializes on low powered but great amps. Who makes the loudest, largest Class A amps ever ? Has anyone ever made a 1 kilowatt Class A ? Prob'ly not.

theAnonymous1 · 12th August 2010, 10:47 PM

Quote:

Originally Posted by vizion

Has anyone ever made a 1 kilowatt Class A ? Prob'ly not.

My 1024W RMS CLASS A+ amplifier.

Too bad we will never see the end of that story.

vizion · 14th August 2010, 04:56 AM

Suffering Suckatash !

kzim229 · 15th September 2010, 05:24 PM

I use this gizmo a lot. Sometimes you want to know the current draw.
Amazon.com: P3 International P4400 Kill A Watt Electricity Usage Monitor: Camera & Photo
definitely worth the $20.

Frank Berry · 15th September 2010, 05:45 PM

The device isn't measuring power if the speaker in and out jacks have virtually zero insertion loss. It appears that the device is measuring the voltage across the speakers and does not take in account the impedance of the loudspeaker.
For accurate measurement of output power, you really need to sample the current going to the loudspeaker using a low value resistor or a current sampling transformer.
Even so, you'll need to be able to calibrate the meter across the audio spectrum based upon the actual impedance of your speaker system at various frequencies.

That is why most amplifier power meters are pretty much useless. They are simply not accurate.

vizion · 17th September 2010, 04:27 AM

I have a kill-a-watt. I used it to measure my amp. Constant power draw is 400w.

11th August 2010, 11:02 PM	#1
vizion diyAudio Member Join Date: Apr 2007	Watt Meter There was an old thread about power meters. I found this little toy that can do the job nicely. Atlantic Quality Design, Inc., The PM-150 Audio Power Meter

15th September 2010, 05:45 PM	#7
Frank Berry diyAudio Member Join Date: Sep 2003 Location: Midland, Michigan	The device isn't measuring power if the speaker in and out jacks have virtually zero insertion loss. It appears that the device is measuring the voltage across the speakers and does not take in account the impedance of the loudspeaker. For accurate measurement of output power, you really need to sample the current going to the loudspeaker using a low value resistor or a current sampling transformer. Even so, you'll need to be able to calibrate the meter across the audio spectrum based upon the actual impedance of your speaker system at various frequencies. That is why most amplifier power meters are pretty much useless. They are simply not accurate. __________________ Frank

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12th August 2010, 05:40 PM	#2
Nelson Pass The one and only Join Date: Mar 2001	Usually I only need to go up to 1 watt.

12th August 2010, 10:33 PM	#3
vizion diyAudio Member Join Date: Apr 2007	Curious, since First Watt specializes on low powered but great amps. Who makes the loudest, largest Class A amps ever ? Has anyone ever made a 1 kilowatt Class A ? Prob'ly not.

14th August 2010, 04:56 AM	#5
vizion diyAudio Member Join Date: Apr 2007	Suffering Suckatash !

15th September 2010, 05:24 PM	#6
kzim229 diyAudio Member Join Date: Jul 2008 Location: Southern California	I use this gizmo a lot. Sometimes you want to know the current draw. Amazon.com: P3 International P4400 Kill A Watt Electricity Usage Monitor: Camera & Photo definitely worth the $20.

17th September 2010, 04:27 AM	#8
vizion diyAudio Member Join Date: Apr 2007	I have a kill-a-watt. I used it to measure my amp. Constant power draw is 400w.

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