please help..!!!! Ive had a problem with my amp for a while now, that when you switch it on its great, but after a short time a clicking noise starts to appear faintly and steadily grows. Ive blow it out with a compressed air can but still it appears, ive unplugged all the speakers bar 1 and all imputs but its still there even through the sub.! no idea and its doing my head in.... any help much appretiated....!!!!