Any time you hook up a multitude of complex electrical components with lots of cables, the rig or setup is probably going to have some annoying electrical noise. It’s a problem electric guitar players have faced forever with varied success.
One of the prime reasons for hum is the ground loop, caused when the sound system has two or more different ground points. This is easy to do if, for example, you plug your guitarist’s amp into the onstage socket, and your mixer into the socket at the back of the house. These separate points will have different electrical potentials, causing electrical current to flow. The result is easy to hear, but how do you fix the problem?
The best solution is to ensure that all AC power is supplied from one single circuit from the power mains. If that’s not enough juice, at least make sure that all your circuits come from the same panel with the same ground.
The ground loop can also be broken by the use of a ground lift adapter, but it’s not a very good idea, as this method is potentially fatal—breaking the ground means that the signal could potentially find its way to earth directly through YOU!
Poor or damaged cables can also be a source of problems as hum can be picked up from crappy power supplies (like most equipment has), light fixtures, motors, and other usual electrical items. Stay away from cheap molded-head connectors, and take time regularly, especially if you gig, to check your cables for good solder joints, clean connectors, and undamaged shielding.
There is another cable-based source of hum induced from power cabling into signal cabling. Briefly, when the two types of cables are running parallel, the AC signal can be picked up by the signal cable, amplified, and broadcast for the world to hear! Keep your power and signal cables well separated; and, if they must cross, always cross them at right angles to each other.
Note: Perhaps, We can learn from the million dollar car stereo audiophiles some of there hum/noise shielding tricks. I know they have some secrets up their sleeves.
Beware of Proprietary Connections When Buying Guitar Gear and Equipment discusses another big time and tremendously baffling problem that produces hum. Power supplies. Some of the other issues discussed in the document help provoke some good thinking patterns pertaining to background noise and hum.
Not sure if these strategies will work? After doing some digestion on both articles GPC invites your solutions and comments on how you eliminate hum from your guitar. Guitar Players Center and the staff knows the subject is important and frustrating at times.
Do you have a structure and strategy in place that works with the equipment and components that comprise your rig? Please Share It with other guitar players. If these strategies don’t work for you, comment on what does! We don’t have the absolute answer, do you?
Thought: You can always run off of battery power. I had a thought on setting up a battery power station using a hidden remote charger to keep the batteries juiced. Has any one tried that, and what were the results?