Arthur Kelm is CEO of Ground One AV Inc., a consulting firm that specializes in power and grounding for professional recording facilities and high-end home installations. Arthur has overseen the electrical and grounding design for some of the world’s most iconic recording studios, including Capitol Records Studios, Warner/Chappell Music, and Sonoma Mountain Studio.
In this blog, Arthur shares some of his advice on how to achieve clean power in a home studio setting to help you capture better-sounding recordings.
What does clean power or balanced power mean?
The term clean power gets thrown around a lot in record studios, but what does it actually mean? According to Arthur, clean power and balanced power is all about reducing the amount of noise generated by electrical sources.
“Clean power is power that has no high-frequency noise," Arthur says. "RF and HF radio waves can be picked up from nearby power lines that run through your neighborhood. Additional noise is generated by motors from household appliances like HVAC units and refrigerators.”
Clean power can be defined through testing and measurement. To achieve clean power, you must keep voltage distortion and harmonic noise content to a minimum. Unfortunately, most utility and generator power are not adequate for sensitive systems like audio and video equipment.
“I look for voltage distortion of less than 1.5%," Arthur states. "My standard for high frequency noise is no more than 150mv Line to Neutral or 50mv Neutral to Ground. It’s also important to have a system that has the ability to provide stable voltage and high transient current.”
The Importance of Stable Voltage And High Transient Current Important
“In regard to stable voltage, most power supplies in pro audio equipment have a range of +/- 10 volts before the Power supply of the unit dropouts of regulation," Arthur says. "If the voltage gets too high, the equipment may be damaged. If voltage gets too low, you get buzz and hum, which increases your noise floor and decreases your dynamic range of all equipment.
High transients are bad for power amplifiers. All power Amplifiers need instantaneous current to move a speaker fast enough to accurately recreate a kick drum or an explosion in a film. If the amplifier doesn’t have enough current from the wall, it’s power supply will sag and the sound will lack punch.” and increase distortion.
The Importance of Clean and Balanced Power
Power quality and grounding are the foundation of any electrical system. If your system has High Frequency noise, it will filter through every piece of equipment in your signal chain.
“Recording equipment is very sensitive to high-frequency noise and transient peaks from motor loads," explains Arthur. "Keeping noise and transients to a minimum is absolutely necessary for the reliable operation and peak performance of audio and video systems.”
“In audio systems, noise shows up as hiss, while transient spikes can damage your equipment and cause power supplies to fail prematurely. Noise in a video system shows up as snow in your picture. With clean power, you have whiter whites and blacker blacks.”
The Effect of Dirty Power on Your Sound
Anyone who’s ever plugged an amp into a questionable outlet knows exactly what dirty power sounds like.
Depending on your power source, you may be dealing with a variety of sonic problems in your studio. The most common is a buzz or hum caused by grounding issues. Sometimes this can be rectified using a ground lift switch, although this is only a temporary solution.
Dirty power can also cause clicks and pops in your audio recording, caused by transient spikes that occur when a motor turns on. This is the nature of electrical motors. The magnitude of the transient is directly proportional to the size of the motor.
“It starts with the noise floor of your equipment," Arthur states. "Noise in your power will transfer to noise in your equipment, like what happens when your refrigerator kicks on, or if you turn on an LED light. Motor loads will put a transient on the power lines that manifests itself as clicks and pops in your recordings.”
Reducing Power Interference In The Studio
In order to control power quality, you need to start at the source. Take a look at how power is being distributed around your studio. For best results, make sure that all of your audio equipment is on a dedicated circuit
That doesn’t mean you need to plug every piece of gear in your studio into a single wall outlet—as a matter of fact, plugging everything into the same outlet can be dangerous and bad for your equipment.
Instead, identify which outlets in your studio are tied to which circuits in your electrical panel. In some home studios, all of the outlets in your room will be on the same circuit, in which case you have to be very particular about what you plug in while recording. This means no space heaters or flashing disco lights.
If the outlets in your studio are tied to more than one circuit, designate one as the audio circuit and mark all of the associated outlets in your studio. Use a surge protector to ensure that all audio equipment is powered by a designated outlet to avoid interference from other types of equipment.
The most important thing is to make sure there are no devices with motors on your designated audio circuit. Motors tend to cause spikes and dips in your power regulation, which can lead to inconsistencies in your recordings. To avoid this, set up shop in a room that doesn’t use the same circuit as your AC or water pump. If you want to include something like a mini-fridge in your studio, make sure it’s on a separate circuit from your audio equipment.
It’s also important to make sure that any lighting fixtures or convenience appliances (like microwaves or coffee makers) with LEDs are on a different circuit. While these types of devices are not always a problem, separating them from your audio equipment makes it easier to isolate your system and speeds up troubleshooting. Fluorescent lighting and dimmer circuits tend to cause the most problems in this area.
“The most common issue I see is people not using isolation transformers for power," Arthur says. "This is the bare minimum. I would start with a triple shielded isolation transformer and you can build from there.”
Finding The Right Solution For Your Studio
Whether you're building a studio from the ground up, looking to improve the audio in your current set-up, or just want to run your rig at home, Vintage King can help solve your power issues. We've played a critical role in supplying tools that offer clean, balanced power to studios around the world.
Vintage King works closely with several brands, including Equi=Tech and Furman, that provide a number of supplies for clean and balanced power in the studio. From shelf and rackmount options like the Equi=Tech Model Q, Equi=Tech Son of Q, and Furman PL-Plus C to larger power conditioners for multi-room commercial facilities, there is truly a solution that will meet and exceed your expectations.