Just finished my very first build and drove myself near-insane trying to figure out why i was dead quiet UNTIL I started playing and then there was suddenly a bad, ungrounded-type hum... almost like distortion unless I grounded the bass by touching the bridge. Turns out it wasn't the bass OR the amp, but the outlet my house! I tried upstairs and its great! So I had this thought that it might be a good idea to list in one place all the things that *could* cause noise... and any tell-tale tricks to identifying that particular cause. The ones I know are: Ground loops Bad joins Single coils hum (not much we can about this one) Environmental- lighting, poor power conditioning etc More?