Having the tuner, processor, and amplifier all in the same box causes interference. Also, needing to pack all that gear into one box forces companies to trim costs on certain components. While high-end receivers produce awesome sound, similarly priced separates will almost always offer better sound quality. Separates do cost more than the average receiver with decent separates starting at around $2000.

The Amp
A separate amplifier is a dedicated box with all its power dedicated to running the amplifier. Separate amps offer a power supply even the most high-end receivers can only dream of. A good power supply is needed so the amp won't have to strain for power during high sound peaks. A separate amp with a good power supply will always have enough clean power will available with plenty on backup for use when the action gets loud. The cheapest 5-channel amps start around $1200.

Preamplifier/Surround Processor
Processors offer the same functionality as receivers do, just without the amps. Since the starting price is $800 on up, the quality of these things usually starts at "great" and just gets better with price.

Preamplifiers usually come without a tuner, and surround processors can be simply described as receivers without amplifiers, or for the ultra audiophiles, they actually mean just the surround processor.

Using separates also allows you to upgrade to new surround formats easier and cheaper. Instead of replacing a $2000 receiver with amps and all, all you need to replace is the surround processor. As 5.1 systems are looking to be the standard audio setup, with even $200 receivers offering both DTS and Dolby Digital surround formats, the more important features that preamplifiers/processors will offer is their connectivity options and user interface offerings.

Surround Formats:
A surround processor should have both Dolby Digital and DTS decoding, and include 6.1 or 8.1 inputs for another surround decoder or playback of DVD-A and SACD music surround formats. Any unit that doesn't decode both Dolby Digital and DTS and doesn't have 6.1 or 8.1 channel inputs should not be considered.

DTS vs. Dolby Digital
Classical music never sounded better than on DTS. Movies sound better by having more surround, more bass, and crisper sound. Many DVDs have come out with both Dolby Digital and DTS on them, but some titles have separate DTS versions, such as Saving Private Ryan. The DTS versions should almost always offer a better surround experience than Dolby Digital, but let your ears decide for yourself and purchase whichever format you prefer.

If your current system lacks DTS don't sweat it. While DTS does sound better the benefits don't outweigh the price of upgrading your gear. Besides Dolby Digital does sound great. In short, if you're buying new gear, get it. If not, don't worry.

6.1
Both Dolby Digital and DTS have come out with a 6.1 channel processing that adds a center channel to the surrounds. This is relatively new and most movies made today don't even support it. The good news is that this format is backward compatible with the older 5.1 processors so those without 6.1 can still enjoy an awesome 5.1 digital surround presentation.

The upgrade price to a 6.1 system is large due the need for a new processor, extra surround speaker, and another channel of amplification. Not to mention trying to locate a surround speaker directly behind you.

SACD and DVD-Audio
If you're an ardent audiophile, you can use the 6.1 inputs on your preamp to connect a DVD-Audio or SACD equipped DVD player. Both formats offer great high definition audio that many audiophiles swear by, but even the greatness of these two formats has met resistance/reluctance to buy $20 audio only DVDs by the general public who hears no difference and audiophiles who've lost interest.

While fun formats to play with, an SACD/DVD-Audio format isn't likely to replace the tried and true CD format or the new kid on the block... MP4 via Apple's hugely successful iPod and iTunes that makes CDs even seem clunky.

What Do You Need?

Preamplifiers / Surround Processors
You need to make sure your processor can accommodate all your existing components while allowing for future expansion.

Minimum requirements:

1. 8-10 A/V inputs with S-Video and Component video inputs
2. Surround decoding of all the latest digital surround formats
3. Sturdy build quality

Amplifiers
Any amplifier you consider should support the requirements needed by your speakers. It should easily have enough wattage and reserve power to drive all your speakers efficiently and without strain. Most any speaker will be easily be powered by any quality amp you can find. Only speakers with low impedance will require more robust amplification. See all your speaker's specifications before shopping.

What Amp is Right For You?
The amplifier will have the greatest impact on the sound quality of your system so, rightfully, this is where you'll spend the most of your time finding the right one.

Different amps will work better with different speakers. Bright sounding speakers will sound better with a soft, laid-back sounding amp. An overly soft sounding speaker can benefit from amp that has more of edge to it.

Any high-end retailer should allow you to take a demo amp home so you can hear how its qualities will match up to your speakers. You don't have to get the same brand amp that you got for your processor. Often, mix-and-matching components offers the best results since the best maker of amps might not be the best maker for surround processors.

Sound qualities to look for:

1. Open airy sound, clear imaging and depth to the sound stage (A great amp can have as big an affect as high quality speakers do.)
2. Very unstressed and clean sound when pushed to high volume levels
3. Smooth non-edgy sound
4. Natural sounding (Vocals are the best test for this)
5. Nonmetallic or non-ringy sound

Connections
Separate amplifiers should have nice binding post speaker connections to allow for solid, high quality, connections. Most every separate amp on the market has this feature.

All amps will have composite RCA jacks for each channel to be connected from the processor. More expensive amps will also offer balanced XLR input connections as well. These offer what many consider much better sound quality than the RCA connection with XLR cables costing easily twice as much. Since the cost is usually much greater using this type of connection you should ask your dealer to give you a demo before adding it to your list of needs.

Another option is a computer looking patch cable that transfers the audio signal digitally to the amplifier.

Sound Quality
When all is said and done the most important thing to attain from a system is the sound quality. Sound quality is more important than any feature or specification. When listening to different amplifiers be sure to be objective.

Don't let wattage be your guide. A five channel amp the uses 80 watts per channels that sounds great is a much better purchase than an amp that has 100 watts per channel that sounds terrible. The reason for such a discrepancy wattage rating vs performance is that all manufacturers don't have to use the same guidelines when measuring. So trust your ears an not the specs. Although when buying separates you'll be hard pressed to find a completely bad sounding amp.

Spending more for better sound only holds true to a certain degree. As with all things, you will find amps that give more bang for you buck, and those tend to be the ones recommended by consumers most often.

Evaluation
The store's environment will play an important role in the sound you'll hear when evaluating different equipment. The best way to review amps is to take the amp and processor home to evaluate how they interact with your home theater system. Many high-end dealers will offer this convenience.

Suggested brands (listed in alphabetical order)

• Adcom
• B&K
• Marantz
• Outlaw
• Rotel