Hohner Revelation, ATN wiring

[psy]

Salve guys,

I always wondered how the so called ATN wiring of '90s Hohner Revelation RTX works and what exactly it does. It has one push/pull pot with a small metal-box on it.
I'm sure anybody of you knows it

This one was my first axe:
http://www.ohrwurm-live.at/images/hohner_revelation_rtx1.jpg
http://www.ohrwurm-live.at/images/hohner_revelation_rtx2.jpg

Thanks, Chris