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View Full Version : Measuring voltage on preamp and amp outputs is AC, right?

grampi
01-25-2008, 10:55 AM
I'm getting ready to set the gains on my system. Measuring the speaker outputs on my amp, and if I want to measure the voltage on my HU's preamp outputs I should be looking for AC voltage, right?

JimJ
01-25-2008, 10:56 AM
Yes.

darkhunter139
01-25-2008, 11:02 AM
I want to try and measure my gains as well. I found an analog multimeter but that should work for now at least.

I know the equation is Voltage = SQRT(Power*Resistance)

But I dont get wth I am suppose to plug into the SQRT(Power*Resistance)

Any help? I have a 250 watt sub and a 500 watt mono amp so I want to set the gains right at 250.

grampi
01-25-2008, 11:15 AM
I want to try and measure my gains as well. I found an analog multimeter but that should work for now at least.

I know the equation is Voltage = SQRT(Power*Resistance)

But I dont get wth I am suppose to plug into the SQRT(Power*Resistance)

Any help? I have a 250 watt sub and a 500 watt mono amp so I want to set the gains right at 250.

This is the procedure I'll be using to set up my system

http://mobile.jlaudio.com/support_pages.php?page_id=143

dragonrage
01-25-2008, 11:49 AM
Measure voltage with a test tone CD. 1kHz is normal (unless it's for subs). I'm not sure what you're trying to do, darkhunter. You shouldn't be calculating voltage. You measure it for the stuff we do and then you use that with either resistance or measured current to determine power.

darkhunter139
01-25-2008, 11:51 AM
Measure voltage with a test tone CD. 1kHz is normal (unless it's for subs). I'm not sure what you're trying to do, darkhunter. You shouldn't be calculating voltage. You measure it for the stuff we do and then you use that with either resistance or measured current to determine power.

Im trying to set my amp to output exactly 250 watts

I think I know what to do now, im gonna go give it a try

ultimate157
01-25-2008, 12:06 PM
Measure voltage with a test tone CD. 1kHz is normal (unless it's for subs). I'm not sure what you're trying to do, darkhunter. You shouldn't be calculating voltage. You measure it for the stuff we do and then you use that with either resistance or measured current to determine power.

He's not measuring power, he's setting the power output of the amp.