Hissing in the Navone NE-774V

I have an 04 chevy with the bose system, xm and onstar. I hooked an Navone NE-774V line output adapter to the system adding a ppi 4 channel and 2 channel amps. Everything sounds good but the there seems to be a hissing noise comming out of all my speakers. It is not an alternator wine or anything like that because I hear it when the engine is off. The louder you turn the radio the less you can hear it due to the music overpowering the hiss. It is like a constant hiss level no matter how loud you turn the radio it stays the same level. You hear it the most when you open the door and the door chime is playing through the door speakers. The funny thing is when I hook up my ipod straight  up to my amp it goes away. I am using the street wires ZN6 series rca cables.

Thanks for the help,

Canoli

either you have a bad convertor/line output. or your gains are set improperly i would reset the gains at the lineoutput convertor and the amp/s. use a test tone cd to set your gains. you can search this subject in this forum. it seems like your experincing feed back noise and improper gains could cuase this. a low quality or improperly connected line output convertor can be the cause also. but start at the gains first befor you 86 the convertor.

did you bypass the factory amp?are the speaker lines that feed the convertor still powering there respective speakers? what is the four channel amp powering?your door speakers?what is the 2 channel powering?subs?give us a little better picture of what you have setup and running.

I know it is not from the amps back because when I plug my Ipod directly to the amps the hissing is gone. I am running 1 set of 165k2p foical in the front, 165CV polyglass in the rear, 2 x 12" image dynamics behind the back seat and 1 pc2600 to the subs and 1 pc4400 the the door speakers with soon to add pc250 to go the the rears and bridgin the pc4400 to the 165 k2ps giving the full 200 watts each.

Everything is wired in after the factory amp, and nothing from the factory amp is feeding anything but  the line output converter. Ohya the factory sub is still hooked and being powered by the factory amp, but we never spliced in to those just the lines going to the door speakers. 

Thanks for the help guys,

Canoli