What Exactly are Power Amps?

[kep1]

Can someone please explain what they are used for? Are they just another kind of amp that people use instead of using a head/combo? Seems pretty hard to find out on my own through the web so thought I'd finally just embarass myself and ask lol.

 

[ez_willis]

Maybe this will help clear things up-

 

[true-eurt]

http://en.wikipedia.org/wiki/Amplifier

http://www.rocketroberts.com/techart/amp.htm

http://images.google.com/images?cli...G=Google+Search&ie=UTF-8&oe=UTF-8&sa=N&tab=wi

 

[Farview]

It is an amplifier that brings a line level signal up to a speaker level signal.

It might also refer to the power section of a guitar amp.

 

[travelin travis]

A basic guitar amp consists of a preamp, power amp, and a speaker. The pre amp amplifies and shapes the small ac signal coming from your guitar to a bigger and hopefully good signal that's ready for the power amp's job of amplifying the signal to push the speaker.

Maybe this will help clear things up-

yep, that cleared it up for me.

 

[jaykeMURD]

Maybe this will help clear things up-

OOOOH! It makes sense now! Duh!

 

[travelin travis]

Can someone please explain what they are used for? Are they just another kind of amp that people use instead of using a head/combo? Seems pretty hard to find out on my own through the web so thought I'd finally just embarass myself and ask lol.

You could run a preamp or a amp modeling box (pod, vamp, etc.) into a power amp and power a speaker cab.

 

[kep1]

so do they take the place of a head or combo amp? what kind of situations are they used in?

 

[ez_willis]

so do they take the place of a head or combo amp? what kind of situations are they used in?

You can run a non-powered mixer into one and have yourself a P.A. for live sound.

 

[Farview]

so do they take the place of a head or combo amp? what kind of situations are they used in?

It is half a head or combo amp.

A guitar head has both a preamp and a power amp in the same box. If you were using something like a POD (which is a preamp), you would have to plug it into a power amp to power the speakers.

 

[SHEPPARDB.]

so do they take the place of a head or combo amp? what kind of situations are they used in?

Have you ever seen a guitar or bass head that has a preamp in?What that
input does is allow you to access the power amp section of the head only.
When you use this input you are bypassing all of the controls in the preamp
section of the amp,such as eq,or anything that shapes the sound.
For instance,if you had an old peavey 400 watt bass head,but you really hated the way it sounded.If you take something like a bass pod and use this
input,you would only be utilizing the power of the head,while the pod would
take care of shaping the tone,effects,etc.
Have you ever used a simple PA system like a head with two speakers?If so
then you understand that the head is what provides the power to the speakers.Have you ever been to a big show and seen a guy sitting behind
a big mixing board?
While the small PA head and the large mixing board share some of the same features,such as EQ,etc.,there is one difference.The big mixer does not have
built in power to push speakers.It needs power amps to do that.Much like your home turntable or CD player will not function without an amplifier to push the speakers.

 

[Richard Monroe]

Yo Kep! A power amp is used anywhere that one or more speakers need to be driven. A combo amp is a preamp, a power amp, and a speaker in one box. An amp head is a preamp/power amp combination that plugs into an external speaker. The most standard uses of a power amp are:
1. to power passive studio monitors
2. To take a line level from a mixer to power PA speakers (Note that a "powered" mixer is a PA mixer with a built-in power amp. Active, or "powered" speaker cabs such as Eon have a built in power amp.)
3. To take the line level from an amp simulator and drive a speaker cab.

Note that most studio power amps are 2 channels, with 4 ohm output, to drive a pair of studio monitors. Some can be "bridged" , combining the 2 sides to drive one 8 ohm cabinet. Power amps for live use are often more powerful (and noisy, with fans for cooling). Studio power amps are usually clean and quiet, but not as powerful. You wouldn't normally drive studio monitors with 1000 watts of barn burning power. It is important that the amp and speakers be compatible, both in terms of impedence and power level.

What is it good for? Let's see. I use a Carver PM125, which is intended for driving studio monitors. I don't use it for that, as my monitors are active. In the studio, I take the line out from a POD Pro, send it to the Carver, and the Carver drives either a 1X12 Marshall cab or a 10" Fender wedge monitor. In other words, it's the power section of my guitar amp. It does the same thing for a bass VAMP and an Ampeg bass extension cab. In live situations, I use a PA that has no auxiliary line outs, or additional power to run monitors (solo gig- small PA). So I take the "tape out", line level shift it to +4 dBu (changing consumer line level for a tape machine to pro line level for the power amp), and use the power amp to drive my floor monitor. You use a power amp anywhere where you want to take a line level signal, and drive a speaker with it.

Hope that helps.-Richie