When you use your volume knob to change from clean to overdrive(for example when you have a Vox AC15) is this as fast as using a footswitch(when you have a 2 channel amp)?
Most people find it's easier to stop on a switch than turn a knob up or down. The knob requires more precision and has a lot more nuance than the switch, so if you turn down to 3 you might get a great clean tone but if you miss and hit 5 instead you might have some OD.
Turning up of course is easier since to go completely dirty you'd just put it to ten.

With some practice I think you'll find that turning the knob is about as quick as looking down and hitting the footswitch; it's not quite as fast, and the change is not as marked, but then you do have that added advantage of having shades in between that you might miss with two different amp settings.

For most people, it's not a big deal to do either. Unless you're playing something with a really drastic, mid-phrase switch from very clean to very overdriven, either method will work fine.
I prefer to use the volume knob, but then again I dont have much of a choice because I dont have a footswitch for my amp, or I'm using Amplitube instead.
Depending on what I'm playing I'll use one method or another. Some songs sound good when you have that quick swell from clean to od while others require the change much faster than your average player could manage without a footswitch.
Quote by Marty Friedman
Because I bend in such an unorthodox fashion; the notes kinda slide up and slide down...
thank you. I think its a good thing to work on that feeling for the volume knob, especially when you like some amps which have only one channel just like the AC15...
It also helps if your guitar has a good volume pot. The one on my OLP is amazing. It gives such a nice and linear output taper that it's mega easy to use. Meanwhile, the pots on my RG are awful things that are almost impossible to adjust on the fly. They do nothing between 10 and 3 1/2, then between 3 1/2-1 you get actual taper. But being that it's all crammed into such a small space it is very frustrating to try and adjust for cleans on the fly.
Quote by Marty Friedman
Because I bend in such an unorthodox fashion; the notes kinda slide up and slide down...
You could build a volume pot into a stomp box if you wanted. It'd be really easy and foot switchable for speed.
[O.¬] - WTF?