Gain

[hendrixrocks]

I've been looking around for a good answer for this question but I cant seem to find one so I'll ask. What does gain do on an amplifier for example. I know sort of what it does but I was wondering how it works from an electronics standpoint. Any comments appreciated.

[lndm]

Maybe less of what it does and more of what it is. Gain is a change in signal level. It is typically measured in dB's. It applies generally in physics, not just electronics.

Naturally, changing the level of a signal (increasing it) is the job of an amplifier. Hope this helps.

[vinylkid58]

Check this out:
http://www.allaboutcircuits.com/vol_3/chpt_1/4.html

Jeff

[hendrixrocks]

So what i am getting from your 2 replies is that gain is just an increase in voltage from one point to another, and the sound that comes from gain is because more current is being pumped through a loud speaker than should be. Is that all right?

[ShinOBIWAN]

Is it not the case that gain is never really applied to the input signal per-se but its actually attenuated at anything other than 0dB. Of course the amplifier stages do their job of increasing output suitable for loudspeakers.

Actually that makes little sense thinking about it

Maybe I've been around digital for too long

[lndm]

Originally posted by hendrixrocks
gain is just an increase in voltage from one point to another

On a different note, a gain can be negative but it often depends on how you use it. A device could be said to have a gain of -3dB, but overall you would say it attenuates the signal by 3dB.

more current is being pumped through a loud speaker than should be. Is that all right?

The thing that pumps current is voltage. You don't force more current through something, rather, you increase the voltage and more current flows.

Gain is simply calculated by taking the amount of voltage (or current or power) at the end of a circuit and dividing this by the amount of it at the beginning of the circuit.