# What's the formula to calculate output voltage on amp?



## JAX (Jun 2, 2006)

I want to get out my meter to see how close I am to correct with my gains. 

I know jl lists there amps voltage out put to set gains 

What was that formula?


----------



## basshead (Sep 12, 2008)

Volts x Volts
Divided by Ohms

This will give you the watts

Is that what you looking for?

If you want the volts for x watts then it is:

Square root (watt x ohms)


----------



## diatribe (Aug 11, 2008)

Do you have JL amps? If not, its going to be impossible to set gains on voltage.

JL amps are regulated, so they will send a steady voltage at an impedance level.

Many other amps are not regulated and their voltage may vary wildly. Especially if you don't have an oscilloscope to find the amps clipping voltage.


----------



## JAX (Jun 2, 2006)

??

People set the gains with meters all the time.

if I knew the max ability of the amps output at rated output then why wouldnt I be able to run a sine wave to it and see how close I am ?

I know with music it would be different and vary with peaks.


----------



## basshead (Sep 12, 2008)

diatribe said:


> Do you have JL amps? If not, its going to be impossible to set gains on voltage.
> 
> JL amps are regulated, so they will send a steady voltage at an impedance level.
> 
> Many other amps are not regulated and their voltage may vary wildly. Especially if you don't have an oscilloscope to find the amps clipping voltage.


Regulated or not the output voltage is always the same whatever the load (within limits). Current draw will change but voltage will not.

100w output on a 4ohms load mean 20V and 5A draw
200w output on a 2ohms load mean 20V but a 10A draw


----------



## minbari (Mar 3, 2011)

go crazy 

Ohm's Law Calculators

its the very last one. put in your wattage and ohm load and it will spit out voltage.


----------



## JAX (Jun 2, 2006)

thanks!


----------

