There is a high frequency whining noise after connection and low frequency audio clicks - the amplitude reduces after approximately 20 seconds but is still audible. Playing a song then pausing it restarts the fault and the process repeats. It is unaffected by volume control and is not audible during music playback unless the volume is very low. Between songs it is distinctly apparent - it's sounds to me like a carrier frequency and the data leeching through to the audio DAC?
Is this normal or a fault? As a design engineer I would suggest it's not normal as the tone is too high and constant to an amplifier problem - it seems far more like communications between devices. There is no such problem in the passive mode using the 3.5mm input but I wouldn't expect there to be. Any assistance you can provide is gratefully received.
I apologise for being unable to give you the exact frequency of this tone as I'm sure it would assist you in diagnosis.
Question by Dr N Kenworthy 10:02pm, 31st December 2016