Head Unit or Bad Connection?

[MA128]

I have a 2013 128 (95,000 miles) with H/K audio. Recently, the sound when playing from an iPod will cut out for a brief moment (<1 sec) about every minute or so. Happens whether driving or stationary. Does not happen when playing any other source.

I'm looking for guidance as to where I should start looking to find the source of the problem.

Thanks in advance,
Paul

This query has also been posted in the 3-series forum.