Hello i was wondering if anyone has ever wired a on off switch or variable speed switch for the fan on the rear of amp? My microphone picks up the noise where i like to run my turner +3B desk mic modulation. The amp is a straight 4 pills with 1446 trans. So how could i add this switch, what type of switch could i use? This amp also has the two lugs on front for mobile power supply. Any help would be appreciated.