Noise During Recording: Part 4
We continue our series on noise in the home music studio with ground loops. A ground loop occurs when different pieces of audio gear that are connected together have different paths to reach electrical ground.
Ground loop noise has a very specific sound that’s related to the electrical grid you’re plugged into, usually a consistent low frequency buzzing sound at 50-60 Hz. This sounds very different than the high frequency hiss of something like preamp noise.
Solutions to Ground Loop Noise
1. If you have a switch marked “ground lift” on any gear, give it a try and see if the noise improves or changes.
2. Plug all of your recording gear that you’re using into the same circuit in your home. An easy way to do this is to have all your audio gear run off a single high quality power supply.
Don’t worry, you shouldn’t trip a breaker: modern audio gear doesn’t draw crazy amounts of power, and you should have no problem plugging lots of gear into the same circuit, if you’ve got modern 15 or 20 amp circuits in your house.
3. Use balanced cables as often as possible in the studio. In a modern studio, the only unbalanced connections you should see are between an instrument like a guitar, and its amplifier.
4. Buy a hum eliminator box. Results can vary on these, depending on exactly how you have them hooked up and where the ground loop is occurring in your system.
5. If you have the resources, an isolation transformer placed on your main studio power line is a great solution here. This can be challenging to implement in the home setting, however. You can buy these as a more expensive pro audio product that’s easy to use from companies like Furman, or use a cheaper standalone transformer from a company like Tripp-Lite if you’re comfortable doing the wiring yourself.
