> … the synth is not freezing and is operating fine unless the audio cable is plugged
> into the either mono audio outs or phones jack, when I do this it will freeze pretty
> much straight away or after two or three seconds.
>… The moment I put the audio cable in it freezes, signal is giving a buzz...

In addition to Paul's reply, a couple quick practical tests should help to focus where to look/what to look at.

1) install a cable into the Polaris' connector but _do not_ connect the other end of that cable anywhere - and evaluate how/if it fails.

2) instead of a non-connected cable, install a pair of headphones into the line jack - and evaluate how/if it fails.

If the same failure occurs with #1 - then the implication is that you're looking for an electrical connection which is being made just by the presence of the jack (e.g., switches on the jack).

If the failure does not occur on #1 but does occur on #2, then the implication is the behaviour involves a connection between ground and signal.

If the failure does not occur on #1 or #2, but does occur when the 1/4" cable is attached between the Polaris and to some other piece of equipment (e.g., mixer, amp, etc.) then the implication is a ground loop being formed between the Polaris and the external piece of equipment.

Note - to give this test more meaning, it is recommended to disconnect all other connections from the Polaris during these tests, including any MIDI, cassette or pedal connections. (This will help ensure that any 'connections' being tested are only ones from the 1/4" jacks - and not be influenced by items such as a ground mis-match between what is on one end of MIDI and what is on the other end of that cable).