2001 cadillac seville sts audio fade cuts

2001 cadillac seville sts with factory navigation system. added an isimple is77 with 1/8" headphone jack input. customer claims audio will fade out within 1 song on his iphone. i had a similar issue with a 2001 cadillac seville sts w/o navigation after replacing the factory headunit and retaining the factory amplifier. songs would soud like they were fading out at the end, but in the middle of the song. we thought maybe active noise cancellation, but no mic in upper front console area. also thought of certain dsp or other setting on the factory headunit active before it was removed. plugged the factory headunit back in and checked for advanced settings. nothing came up or was present in this vehicles owners manual. wondering if anyone else has ran into this or could provide some insight?

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nice...

Just about everyone of those blasted things I have done has come back with either the ipod connector causing random noise loss or the aux jack being worn out. I don't know if people are being super rough with them or they just are not a quality piece.

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To master and control electricity is perfection. *evil laugh*