The Surge Protector that you can get for less than $10 just about anywhere, even the grocery store, is not a line conditioner. It is merely to keep your system - be it a home theater or computer - from cooking if lightning hits your power pole outside.
True line conditioners have filters or other circuits that are designed to low-pass your incoming AC power so that RF is filtered out. RF could be defined as frequencies above the audible band, but since we may be able to hear - or "sense" - frequencies up around 50 kHz, practically speaking, RF is 100 kHz and above.
The reason RF is important is that it interacts with the audible frequencies (20 Hz to 20 kHz) even though you cannot hear the RF itself. The interaction produces distortion. So, anything that can reduce RF from getting into your A/V system (including the display) is good.
ExactPower manufactures several line conditioners (also called line purifiers). Their EP series looks at the AC signal and adds small signals that fill-in the wave form to make it a sine wave.
Balanced power is also a desirable factor in AC supply, as it helps the ground connection do its job more efficiently. The EP15A does not have balanced power, but you can get their SP15A and connect it to the EP15A if you want balanced power and the line conditioning that the EP15A delivers.
Unfortunately, the combination of such circuitry is very expensive. So, ExactPower now has introduced the UltraPure, which, although not having the circuit in the EP15, has filtration (heavy inductors) designed to low-pass the incoming AC and remove as much of the RF as possible. It also has two balanced transformers that give you a total of 900 watts balanced AC, split into two separate circuits, so you can keep some components electrically isolated from one another.
The front panel is simple, with a brushed aluminum front, and an On/Off button with an LED indicator above it.
The rear panel has several sets of AC output sockets. On the left are four sockets (two pairs) that deliver UltraPure Symmetrical Filtration. This includes balanced AC that is filtered with additional components. The middle two sockets (one pair) has Symmetrical Filtration, which uses the balanced transformer's inherent filtration of high frequencies (because it is an inductor, which acts as a low-pass filter). On the right are four sockets (two pairs) for use with power amplifiers. They are not connected to the balanced transformer.
The AC input socket is removable and grounded (three-pronged).
The total output is 1,700 watts, which should take care of your DVD player, Satellite Box, and A/V Receiver. I would connect the DVD player, Satellite Box, and an SSP to the UltraPure Symmetrical Filtration (200 watts maximum), and a modest sized receiver to the Symmetrical Filtration (500 watts maximum).
Click on the photo above to see a detailed version of the rear panel.