I just noticed that you said DVD not CD changer. You definately want to use the coaxial digital or else you won't get DD 5.1 unless you hook up 5 analog cables to your 5.1 "ext. in" on the 525.
I would still simultaneuosly use the front L-R analaog audio outs on the DVD player into the 525 if you want to poweer a second zone for DVD/CD audio.