[s_morrison57]

Originally Posted by Jeff Hail

Gain adjustment or "drive" is where the fun begins. Turn your guitar volume down. Turn your amp master volume to 2. Set your gain at about 5 or 6. Slowly turn up the guitar volume why strumming, see how the sound changes from clean to gritty as the distortion increases. Gain or drive pushes the pre amplification stage. Fine tune your tone to suit.


Gain versus volume:
That first stage is the preamp stage. On some amps, you can control the level or strength of the signal sent through this first stage; this control is called "gain" (also often labeled as "drive"). Gain can be thought of as the input volume to the preamp stage (gain adjustments can produce changes in overall volume, which might account for some of the confusion between the terms), although it's more of a tone control than a volume control. Your gain setting determines how hard you're driving the preamp section of your amp. Setting the gain control sets the level of distortion in your tone, regardless of how loud the final volume is set.

What this means is that your gain setting determines how clean or dirty your sound is regardless of the master volume setting. You can set the gain high for a dirty tone, but set the overall volume of that dirty tone from near silent to near deafening using the master volume control.

Master volume is an entirely separate entity that lives in the second stage of your amp, the power amp section. It provides the muscle. Think of it this way: the preamp (and gain control) provides the shape of the sound; the power amp provides the overall strength of the sound.

In amps with only a single volume control (and no gain control), that volume control is usually placed early in the signal path - in the preamp stage - thus controlling both volume and gain.

Thanks Jeff, that makes a bunch of sense when explained the way you have.