Just wanted to give a big "shout-out" to cbrillow for being such a great resource here!
I had been searching (off and on) for a Line 6 XPS-AB pedal or replacement alternative for literally months.
I play live extensively with a JTV69 and a Standard and wanted a backup to my original XPS-AB pedal, especially since I didn't really want to have to worry about charging batteries.
Luckily, I found his post. Not only did his solution totally work for me, he was also kind enough to answer some of my incredibly "smooth brained" questions.
If I could build this solution, believe me, ANYONE can do this.
Disclaimer - I'm just a guitar player with no technical background in electronics. I'm just sharing my experience. I'm NOT telling anyone to go out there and do this because I don't want to be held responsible if things aren't followed properly :-)