You can find power protection components to accommodate just about any system.

For a lot of folks, power protection means plugging everything into an inexpensive power strip with a circuit breaker. While that can be adequate for some electronic devices, general purpose power strips may not fully protect sensitive audio/video components from damaging power spikes. And they seldom filter out the everyday electronic interference from your home's circuitry, phone line, and cable connections that can affect your system's performance.

Power protection components come with a variety of options to meet the specialized needs of various systems. In this article, we'll explain those options. We've also put together a simple list to help you make sure the power protector you're considering has the right features for your system's needs.

Why do I need power protection, anyway?

You probably know someone who has lost a TV or computer to a power surge during a thunderstorm. Preventing that kind of damage is a big part of what power protection does. After all, unplugging your TV during a storm may not be enough; if your cable box or satellite receivers remain connected, you've left a "back door" open for that lightning strike.

Less dramatic — though more pervasive — is the damage done to audio/video systems by minor fluctuations in power, sometimes called "brown outs." Electromagnetic interference and radio frequency interference generated either by other devices in the home (like vacuum cleaners and blenders) or sources outside it (like nearby power lines or radio towers) can also impair your system's performance.

Inexpensive power strips seldom offer that level of protection. They normally just break the connection if too much power comes through the line. And even there, cheap strips can fall down on the job. Because general purpose power strips have higher tolerances than expensive audio/video equipment, a surge that could damage your components could pass through the strip and still be under the voltage required to trip the circuit breaker.

To select the right power protection unit, you should consider the components it will be connected to — both now and in the foreseeable future. This can help you select a unit that provides an appropriate level of protection for your system.

Surge protection

Lightning strikes or power company overloads can create surges that could fry your gear in less than a second. If all your audio/video gear is plugged into a surge protector with AC outlets, you might think your system is protected. But these power spikes can also come into your home through your phone line, your cable TV line, and your satellite signal line. You'll want to make sure the power protection device you choose can accommodate all of the lines that connect to your system.

Surge protectors sacrifice themselves to save your equipment. They're designed to be the weakest link in the chain from the power source to your equipment, and include circuit breakers or fuses that immediately sever the connection when a large electrical spike hits.

Many surge protectors can also sense if your home's wiring is properly grounded, and will alert you if a fault is detected. Improper grounding is often the source for audible low-level hums in your speakers.

Better quality surge protectors usually carry warranties that cover damage to connected equipment if they fail to contain a power spike.

Line conditioning

Electromagnetic and radio frequency interference (EMI and RFI) won't fry your A/V gear, but they can hinder its performance. Devices with digital inputs and outputs, such as DVD players, receivers and LCD TVs, seem especially susceptible to "dirty power."

• EMI is caused by an electromagnetic field generated close to your system. Sometimes it can be contained in the current that comes into your home. A washing machine, vacuum cleaner, or blender can add a loud buzzing or a low hum to your audio system. EMI can also affect the quality of your TV picture in the form of "snow" or overall reduced clarity.
• RFI results from radio waves that can be generated by radiostations, microwaves, cell phones, lawn mowers, and many other sources. These interference patterns often originate a great distance from your home, and can be heard as clicks and pops. Your home's electrical circuitry can act as a crude antenna, sending RF signals through your system's power cords and into your gear. Sometimes cell phone conversations or nearby radio transmissions can actually be heard through your system's speakers. RFI can also cause "snow" in your TV's picture, dulling image details and washing out contrast.

A power protection component with line conditioning can remove most of this interference, allowing your system to perform at its full potential.

UPS units can keep your gear on when the power goes out, so you can shut it off safely. (Panamax M1500-UPS shown)

Uninterruptible power supply (UPS)

If you've ever lost work on your computer when the power suddenly cut out, then you can appreciate the value of an uninterruptible power supply (UPS). UPS components contain internal batteries that provide power to your equipment during temporary power outages. Typically, UPS components can provide power for a few minutes, long enough to ride out short blackouts or to save your work and shut down your system properly during prolonged outages.

Along with preventing lost data, a UPS can help extend the life of your gear. Many audio/video components are stressed by improper shutdown, which affects their performance and may shorten their operational lives.

Also, a UPS can prevent the loss of personalized settings in your audio/video components, such as channel programming with your satellite receiver, TV, or cable box. This is helpful for components that rely on an internal clock, such as a DVR or VCR.

Uninterrupted power is especially important for "big-screen" or rear-projection TVs. Many of these sets use a powerful bulb to create a picture. Because this bulb gets very hot, an internal fan runs for several minutes after the TV's turned off to cool the bulb down slowly and safely. A UPS component allows the cooling fan to run even if the power goes out suddenly, extending the life of the bulb.

Power regeneration units provide the cleanest possible power for the best audio/video performance.(PS Audio Power Plant Premier shown)

Power regeneration

Heavy usage elsewhere on the line, brownouts, and accumulated line noise can all affect the power coming into your house, sending an irregularly fluctuating current into your gear. High-performance electronics, such as flat-panel TVs and high-end DVD players, are extremely sensitive to these changes. Power regeneration smooths out these irregularities.

Rather than just filtering your house current and passing it on to your gear like a line conditioner, a power regenerator uses it to create its own power to send to your equipment. Incoming AC (alternating current) is converted to DC (direct current) to strip off electronic noise. The DC current is then regenerated as AC through circuitry that tightly controls the power flow, eliminating as much variation as possible. This regenerated AC power has virtually none of the noise or fluctuation of the original current, ensuring that your system gets clean, consistent power.

Additional features to look for

Your power protection component can offer benefits beyond surge protection and line conditioning. More advanced features include:

• Sequential outlet turn-on — First sends power to your playback components, like a tuner or DVD player, and then to your receiver or amplifier after a brief delay. This eliminates the infamous amplifier turn-on "thump," which can damage your speakers.
• Offset outlets for AC adapters — The bulky AC adapters that come with small devices like rechargers and game consoles requires only one outlet. When plugged in, they fully or partially cover the adjacent outlet, preventing its use. Offset outlets place additional space between the plugs to accommodate these larger "wall warts."
• Out-of-the-way mounting options — Some power protection units include hardware for mounting on a wall or a component rack.
• Additional phone line connection — Some components require connection to your phone line, such as a TiVo® recorder or satellite TV box. Many people don't realize that electricity can travel through a phone line as well as a power cord, and so often leave this "back door" open for catastrophic power spikes.
• Isolated outlets for digital sources — Reduces the high-frequency noise generated by digital equipment, such as DVD players and flat-panel TVs. The outlets are arranged in isolated banks — one for digital components, and the other for analog audio and video components, like receivers and amplifiers. This keeps interference from the digital components leaking through the outlet and interfering with the analog gear.

Matching special power protection features to your gear

While we can't cover the power protection needs for every kind of audio/video component in an overview article such as this, we can touch on some of the most important aspects to consider for some broad catagories of equipment. Here are a few features to look for if you have any of the following:

Some line conditioners install on your wall or even flush in your wall, making them a great cosmetic match for wall-mounted TVs. (Monster® In-wall PowerCenter™ shown)

LCD and Plasma TVs — Line conditioning
Electronic noise from an unfiltered power source can visibly affect the picture a flat-panel TV displays — especially high-definition images. While the effect isn't as dramatic as the "snow" that appears on a tube TV, it nevertheless impacts performance.

In a flat-panel TV, electronic noise can cause individual pixels to shine slightly brighter than those around them. Even though a single pixel isn't visible to most people sitting at a comfortable viewing distance from the screen, thousands of these affected pixels scattered across the screen can cumulatively have an impact. The effect is generally a softening of image contrast, with washed-out blacks and poor shadow detail.

Line conditioning minimizes this electronic noise, allowing the image to remain sharp. For extremely sensitive high-end electronics, a power regenerator may be required to completely eliminate visible noise.

Rear-projection TVs — Uninterruptible power supply (UPS)
Many rear-projection TVs use an extremely bright and powerful bulb. This bulb becomes very hot during normal use, and is cooled by a fan inside the TV. When the TV is turned off, the fan continues to blow for a few minutes to ensure that the bulb cools down properly.

If power to a rear-projection TV is suddenly cut, the fan stops before the bulb's sufficiently cooled. This fatigues the bulb's glass (like putting a warm glass in a sink of cold water), and significantly shortens its operational life span. A UPS component keeps feeding current from its backup battery to the TV if the power suddenly goes out, giving you an opportunity to turn the set off so it can shut down properly.

Systems with separate amps and preamps — Sequential turn-on
Some higher end systems use a separate preamp and amp. A preamp usually requires a few seconds after it's turned on to stabilize, while an amplifier is "ready to go" almost immediately. These two components shouldn't be turned on simultaneously. If they are, you may hear a loud, possibly harmful "thump" to sound in the speakers when the amplifier kicks in before the preamp can fully control it.

While one could turn on each component in the proper order individually, a power protector with a sequential turn-on (and turn-off) usually fills the bill. When this kind of power protector is turned on, its various outlets send current in a set order, allowing time for those components that need to "warm up" before the rest of the system gets turned on.