Recently picked one of these up, and I'm looking to insert it into my BDU chain. Does anyone know if this model has polarity protection and/or a wiring diagram online somewhere? Google has failed me...

Thanks!

Reversed polarity could cause catastrophic damage for sure.
According to the manual, 13VDC is the recommended external voltage.. So a 9 to 15.volt DC external power source (center pin positive) should work.
BTW, Why don't you just ask the nice folks at Marantz pro?
Marantz/Denon Professional USA (http://denonpro.com/)