Hissing sound on first gen picade

Hi, i’ve a first gen picade with an audrino board and pi4 and get terrible sound from the 3.5mm audio with loud hissing coming out of the speakers.

Can anyone suggest any solutions? Ideally would like to keep the buttons on the side for controlling the volume if possible.

I ripped out the audrino board in the end and put a zero delay and soundbar in there.