Very often we get enquiries from customers about hum issues in their guitar rig. Sometimes it's problem with their amps or pedals / pedalboards (especially with powering the pedals). However in most cases the hum comes from a guitar. Usually a dirty power in some venues, light dimmers (either stage ones or those use at home), laptops / desktop computers or their switching mode power supplies make it even worse.
Now we'll tell you how to find out if it's your guitar humming or something else in your setup. It's very simple. Connect the guitars, pedals and the amp as you normally do. Set the levels to usuall volume you play with. I'm sure you get some hum, hiss, etc. Now turn the volume control down to zero. Is the hum gone? If so then it comes from you guitar. If it's still there - it comes from the rest of your rig. If it's partially gone then part of it comes from the guitar and part of it from the rest of your guitar setup. Easy, isn't?
Obviously single coil pickups will be much more noisy than humbuckers. It's worth mentioning that P90s, Jazzmaster and similar pickups are pretty much an over-wound single coil pickups and will be also pretty noisy.