A noise gate does exactly what it says on the tin; the gate ‘opens’ when the level is above a certain threshold, and ‘closes’ when it falls below, only letting in your desired amount of signal. In most cases, your actual playing will be far louder than the hum of your rig, so you can set the threshold to sit at the same level as the hum. All it takes is a little bit of experimentation, and hey presto – no more noise!
Noise gates are particularly popular among the high-gain crowd - modern metal, djent, prog-rock. These artists tend to combine loud, distorted sounds with lots of space - the perfect storm when it comes to rig noise.
Some people can live with the noise, and some purists think it’s old-school, but for most us we just want to do everything we can to reduce hum. So what causes unwanted noise?
- Type of amp – valve amps get noisier with age. Solid-state amps are arguably more reliable, and therefore don’t produce as much noise. But anything high-gain will inevitably buzz a little more!
- Amount of Volume and Gain – all amps have a noise floor, i.e. a certain amount of hum or buzz by default. The more you boost gain or volume, the more hum you’ll get – it’s all relative.
- EQ Settings – if you boost your treble or mid frequencies to cut through a mix, there’s a chance you’ll accentuate the unwanted noise from your amp.
- Types of Pickups - Single-coil pickups tend to generate more noise due to their design, while humbuckers are designed to reduce hum, hence the name.
- AC Supply and Interference – the quality of your mains supply can also affect the amount of noise your rig makes. If the AC supply in your area is poor, this can cause the amp to emit more noise due to lack of ‘clean’ power.
- Radio and static interference – phones, radios, Bluetooth devices, electrical appliances. They can all cause unwanted noise if they happen to be close enough to your guitar or amp.