Setting Gain on a PG Xenon

[jrvette94 10+ year member]

Has anyone had experience setting the gains on the PG Xenon series?

Because of the "XeLoad" circuit it would seem that the standard practice of setting the output voltage (using a DMM) based on power and load may not apply with these amps.

If the amp adjusts the output power based on the resistance of the speakers wouldn't you have a different voltage when the speakers are connected after setting the gain with a DMM?

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[jrvette94 10+ year member]

I guess I have to post some dumb *** NooB question like "What is the best system I can get for $200?" in order for anyone to take a look at my thread or post a response.

 

[AznRevlAzn 10+ year member]

more like, theres a fvcking sticky in the amplifier forum to answer your question. Learning is better than being told what and what not to do because eventually, someone screws you over //content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif set it to 9824097257 AC volts by the way testing with a -25Hz tone...

 

[jrvette94 10+ year member]

Read the complete post, not just the heading!!

I know how to set the gain on a typical amp, done it many times. The question is will the standard gain setting procedure work with an amp that adjusts power based on load.

In theory, with this amp, the voltage will be different w/ 4ohms, 2ohms or 1ohm with the gain set at a fixed position.

 

[jrvette94 10+ year member]

I misspoke in the above post. The amp's power is constant for each load. If the power is constant and the load changes, then the voltage must change as well for different loads.

For Example:

P=400 watts

I = 4ohm, 2 ohm, 1 ohm

@ 4ohm, V = 40

@ 2ohm, V = 28.28

@ 1ohm, V = 20

The question still remains, how do you set the gain when the voltage changes based on load? The only thought I have is to use a dummy resistor that matches the speaker, then you could use the DMM to set the gain, but I can't find a 600watt resistor to use.

 

[squeak9798 5,000+ posts]

It works exactly the same as it does with any other amp.

PS: Being a ******* impatient jackass isn't the way to encourage people to want to help you.....

I guess I have to post some dumb *** NooB question like "What is the best system I can get for $200?" in order for anyone to take a look at my thread or post a response.

 

[jrvette94 10+ year member]

OK, I called the factory and eventually got in touch with someone that could give me a decent explaination.

He said "if your HU volume is set constant and your gain level is set constant the amp's output voltage will be different depending on your load (1-4ohm), the power would be the same (independent of load)".

This is different then a typical amp. With a typical amp the voltage would be constant, but your power would be different depending on your load.

 

[squeak9798 5,000+ posts]

OK, I called the factory and eventually got in touch with someone that could give me a decent explaination.
He said "if your HU volume is set constant and your gain level is set constant the amp's output voltage will be different depending on your load (1-4ohm), the power would be the same (independent of load)".

This is different then a typical amp. With a typical amp the voltage would be constant, but your power would be different depending on your load.

But you can still set it via the DMM method in the sticky since ohms law still applies exactly the same.

Ever look at the gain setting tutorial on JL's website? They use the DMM method and Slash series amps for their examples, and urge you to set the gain using the same method. The Slash series amps also have regulated outputs, like the PG Xenons.

What does this tell you? That the method works just fine for those amps aswell.

Ohms law doesn't change.

 

[DBfan187 5,000+ posts]

most DMMs read P2P voltage instead of RMS. 60Hz is said to be the most accurate.

If I were you, I'd invest in an oscope.

BTW, I'm loving this 3:1 overlap.

 

[DBfan187 5,000+ posts]

in return for ****** pleasure?