I am looking to set up a simple music source for my backyard. I'm wondering if I can use a 3.5mm to stereo RCA cable to connect my iPod / iPhone / iPad directly to my Adcom GFA5300. Amp specs are input impedance 49.9 kOhm, input 0.1V output 1W, input 0.9V output 80W. I can't find iAnything specs for the 3.5mm output jack. Will I get a clean usable signal for the amp? Will the iDevice volume control be adequate for setting speaker levels?