Correspondingly, what does a master volume do on an amp?
A master volume are basically allows the user to turn up the pre-amp section while controlling the signal going to the power amp thus controlling the overall volume of the amp. In a non-master volume amp this control does not exist.
Similarly, does Master Volume affect tone? A good master volume would add some flexability to the amp and make life just a bit easier. When dimed, the MV does not affect the tone much, just a little. But you really do not want a PPIMV, because the good sound of the amp occurs only when the volume is full open.
Then, what is difference between gain and volume?
Conclusion: Gain Vs VolumeSo remember: gain and volume are very similar concepts, but their difference is very important to your mix. Volume is how loud the OUTPUT of the channel or amp is. Gain is how loud the INPUT of the channel or amp is. It controls tone, not loudness.
Does gain increase volume?
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. Master volume is an entirely separate entity that lives in the second stage of your amp, the power amp section.