Found this while looking at the main site for that NirCmd utility kizer just linked up.
http://www.nirsoft.net/utils/volumouse.html
Lets you use the scroll wheel on your mouse to control the master output volume from Windows. Now, probably not many of us will have a scroll mouse attached to our cabs, but it's not hard to crack open a cheap mouse and hack the scroll wheel so you can attach it to any knob you want, and Blammo!- Instant volume knob.
I just tested this, and you can configure it so the scroll wheel only controls the volume at certain times, like when you press a button or have the cursor in the screen corner or have WMP running, or about a brazillion other things. Or, you can set it for "when no button or key is pressed", which is perfect if you're building a dedicated volume knob for a juke.
Arcade dorks with an Opti-Wiz from GroovyGameGear can make use of this by connecting their spinner to the Z-axis on the Opti-Wiz. Turn your cab's spinner into a volume knob, how handy is that?
Dude,
I was just looking for something like that a while back. Thanks for the post. I was going to relocate my amp volume control, now I can just gut a cheap mouse like you said.
Good find. ;D