Different phone speaker system humming when no music

The humming comes from the sound system (speakers). Its strange to me that it only starts humming in the a5 but not on my 3t was guessing that the phone headphone jack is the problem on the a5, the same issue is for my Bluetooth dongle that connects to the amp through a 3,5mm jack. So should i try looking at the headphone jack on the a5?

No humming:

When not connected

When 3t is connected with no music

When 3t, a5, Bluetooth dongle playing music(sending some signals)

Humming:

When a5, Bluetooth dongle are not giving any signals for music

Connections:

Speakers < amp < 3.5 mm jack for music also for the phone alarm

this does not sound like an issue with the headphone jack or your Galaxy A5. I would not mess with it. Let us know what the sound on your phone is like when you use a pair of non-amplified head/ear phones.

Hi @manttv ,

Just curious.

Are you using a 4 pole plug cable between the phones and the speaker input or a 3 pole plug cable?

To me it sounds like a earthing problem.

You could try making up a cable with only the left and right channels connected i.e. tip and ring connection only at each end with the sleeve connected at one end only to provide shielding and see if that works.