Okay so I have a relatively new amp/cab set up (it's about a year old now).
the set up is:
Ashdown MAG 300 Evo II head.
Ashdown MAG 210T Deep Cab
Ashdown MAG 115T Deep Cab

I bought them all, in a bundle (from a reputable company in the UK) in June last year (2010).

However, in the last week, whenever I turn my amp on and plug my bass in (sometimes even with no bass or lead plugged in) the speakers (it seems to both) make this horrible clicking sound.
Could someone point me in the right direction, if not how to fix it, at least what the problem might be!

The worst thing is that the problem seems to be sporadic and not constant!

Any help would be appreciated