I will try and make this simple to understand but i have a custom modified sub amp from rythmik audio. im not using it currently added relay circuit yet but i do have a 12V power supply tapped off of the incoming 120V power on the amp (where the plug goes inside to the back of the amp i have a 120VAC -> 12VDC transformer tapped off of it) the tap is added before the amps PSU, so it is not putting any drain on the amps psu. HOWEVER i have a switch wired in that allows me to cut the 120VAC power to the 12V transformer...turning it off and keeping heat out. when i turn the switch on or off it usually makes a huge pop or bang noise (no bottoming out though) which im guessing is from the switch arcing. how can i solve this.... i found this on another site... is it accurate and will it work? or is there any other circuit i can build?