You can't reprogram the All Start / Stop button, which is stupid. I don't know why they didn't allow for this, but they didn't. You can reprogram the FX button if you want, though. And the Assign system allows you to overload programmable buttons so that a single button can do more than one thing with a single press. It's much easier to do that than it was on the 50.
I made this tutorial about the Assignments btw.
There is probably a way to set up the function you mention, John. Starting or stopping a track is one of the sources for triggering assignments. I've found their behavior to be kind of confusing though. But that's another story.
Subject: Re: might be that time
Date: Mon, 20 May 2013 13:34:19 -0600
My two cents as someone who went from the 50 to the 300. It takes a little getting used to, but I find the loops themselves to be much cleaner, and dare I say sonically improved? If you're using it with a group you may have found like me that the sub out is very useful for sending at loop only signal to your drummer or percussionist which the 300 still has.
I don't even mess with the effects, and they've never gotten in the way. I do really enjoy the _expression_ pedal for volume. I am pretty right foot dominant when it comes to looping starts and stops, so I found that I still am more comfortable using an auxiliary foot switch to trigger the "all stop/all start" function even though there is a dedicated pedal for that on the unit. I think you can program that to do something else, like maybe clear the loops?
The one thing I haven't spent alot of time on that I used to do with the 50 was to set up a second track to start recording and sync with a first track...after I had used the all stop. I'm guessing there's a way to do it.
Hope that's helpful,