Intro to home audio power amplifiers and preamps
How to build a high-performance home audio system
In a nutshell: Do you crave exceptional, immersive sound when listening to music and watching movies? Then maybe it's time to step up to "separates" — stand-alone preamps and power amplifiers.
Learn how to build your dream system. First we’ll explore stereo preamps and surround sound preamp/processors. Then we’ll look at range of different amplifiers, each designed for a different application:
My home audio system is a work in progress. I started with a sound bar. When I could afford it, I moved up to a stereo receiver with bookshelf speakers.
Since then, I’ve added a turntable and a nice CD player. My receiver-based setup made them sound pretty good, but I wanted great, fantastic, sublime.
Now I have a separate preamplifier and power amplifier, and I have to say — I love them.
In my home system, a NAD C 165BEE preamp offers plenty of inputs for my turntable, CD player, cable box, and gaming system. A beefy Marantz MM7025 amp powers the speakers and makes everything sound divine.
Why buy a separate power amplifier and preamp?
Typical stereo and home theater receivers are practical and versatile. Like minivans and family sedans, they’re exactly what many people need. Separates are more like sports cars — you get all of the power, performance, and downright fun you could ever ask for.
A preamp is the hub to which you connect your source components. Stereo preamps typically have tone, balance, and volume controls, as well as a switch to select the component you want to play. They may include a built-in network music player.
Why put these circuits in a separate component? Two main reasons:
First, you get better sound. Because product designers don't have to cram so many parts into one box, they can lay out shorter signal paths. Sensitive low-voltage preamp circuits don't sit cheek-to-jowl with the high-voltage amplifier parts. And the amp and preamp don't have to share the same power supply. You get less noise and more horsepower.
Second, you get more freedom of choice when it comes to system-building options. The right combination of preamp, amp, and speakers will give you extreme fidelity and clarity. Trust me, it’s the kind of sound that will raise goosebumps.
What to look for in a home theater preamp/processor
Think of a surround sound preamp/processor as a high-end AV receiver without the built in amplifier.
It takes care of video processing, surround sound decoding, input switching, and audio signal processing. It may have built-in Bluetooth and streaming apps like Spotify. Most models offer some sort of room correction software that helps maximize sound quality for your space.
When you let a separate power amp take care of driving the speakers, the processor can focus on doing everything else extremely well. That means outstanding audio performance that will make stay-at-home movie nights more popular than a visit to the theater (and hey, the popcorn is certainly cheaper).
When choosing a preamp/processor, make sure you’ll have all of the inputs you’ll need. Chat with one of our expert advisors if you’re not sure.
The preamp’s outputs go to your amplifier, of course. Surround sound preamp/processors also have HDMI connections for your TV.
High-end preamps and preamp/processors often offer balanced XLR connections. XLR cables reject noise that can mar your listening experience, and work very well over long cable runs.
How to choose a separate power amplifier
There are a lot of amps out there, so how do you decide which one will work best in your home? It helps if you know how you want to use it.
Here are some primary categories to think about. We’ll start with hi-fi stereo amps. Then we’ll look at multi-channel home theater amps. Later on, we’ll look at a range of amps designed for multi-room music systems.
How much power do you need? That depends on how close you want to get to concert-level volume and dynamics or theater-like sonic impact. It also depends on your speakers. Some power-hungry speakers sound best when paired with an extra-stout amplifier.
Hi-fi stereo and monoblock amps
The amps featured in this section are perfect for a high-performance stereo music system. There’s no reason they can’t be used in a surround sound system, though multi-channel amps might make more sense in your theater system.
To get an idea of how these separate amps differ from the amps inside a typical receiver, take a look at the guts of each.
Compare the clean, uncluttered layout of the power amp on the left, to the crowded insides of a standard receiver on the right.
Take a look at the amp on the left in the photo above. You'll notice a large round part bearing the Yamaha logo. That's a torroidal transformer, a key element in the power supply of nearly every hi-fi amp. You won't find them in a lot of receivers because of their size and cost.
Toroidal transformers give you two major benefits. They give off far less noise and hum than ordinary EI transformers. And they generate much more power than comparably sized EI transformers. They can easily deliver the juice that's needed for dynamic peaks in movie soundtracks and music performances.
Sample amp/preamp pairings
How do you choose the right amp/preamp combo for your stereo system? One good way is to chat with one of our expert advisors. But I’ll whet your appetite with a few suggestions.
NAD offers a wide variety of amps and preamps work well together in a classic hi-fi stereo setup. A solid entry-level system would include the C 165BEE stereo preamplifier and the C 275BEE stereo amplifier.
The Cambridge Audio Azur 851N is a customer favorite preamp that’s meant to be paired with the Azur 851W amplifier. This system fully embraces high-res digital content, with a built-in network music player and top-shelf digital-to-analog converters for your other digital audio components.
Do you have to stick with the same brand?
While an amp and preamp from the same brand look great together, there’s no reason you can’t mix and match. Just choose a stereo preamp and a two-channel power amplifier, and you’ll hear your music come alive.
Home theater amps
A strong home theater system creates an immersive soundstage that brings a realistic edge to TV and movie soundtracks.
This is where the versatility of separates really shines. You can choose a powerful 3-channel amp to drive the crucial front left, right, and center channels. Surround speakers that require less power can have their own dedicated 2-channel amp. Or you could keep things simple and get one amp with enough channels to drive all of your speakers.
Here are a few suggested combos. Contact a Crutchfield advisor if you need help designing your system.
There are several Marantz preamplifiers that team well with one or more of their robust power amplifiers. This is a great way to go if you want flexibility in designing your ideal system.
The best-selling Marantz AV8805 is a home theater buff's dream, with plenty of inputs for a 13.2-channel surround sound setup and HEOS multi-room technology built in. You can then use a Marantz MM7055 to drive your left, right, center, and height speakers, and add up to four Marantz MM7025 stereo amplifiers to power surround speakers and separate zones as needed.
Anthem is what you might term a “power player” in the surround sound world. Their extensive lineup of rugged power amplifiers lets you customize your system’s power distribution.
Anthem's lineup of preamps and power amps are built to deliver maximum power and system design flexibility.
Start building your dream system with Anthem's sophisticated AVM60 preamp. It's a home theater lover’s dream, featuring the acclaimed Anthem Room Decoding calibration software. The MCA 325 power amplifier provides up to 400 watts per channel for the all-important front left/right/center speakers, then you can power the rest of your surrounds and effects speakers with multiple MCA 225 stereo amps.
Passive subwoofers (mostly in-wall models) require a separate amp. It’s common to bridge the output of a stereo amplifier, so it becomes a powerful mono channel. This will work for most subwoofers.
That said, some subwoofer manufacturers offer monoblock amplifiers that are designed for use with a specific model of sub. For example:
- Monitor Audio IWA-250 amp matches Monitor Audio IWS-10 in-wall subwoofer
- Polk Audio SWA500 amp can power their CSW155 in-wall sub, plus the CSW100 and CSW200 in-floor models.
- Revel SA1000 pairs with the Revel B28W in-wall subwoofer
Multi-room amps are not to be confused with the high fidelity stereo amps we talked about earlier, but they're good, solid building blocks for a multi-room system. Many models have specialized connectors for remote control, power triggers, and infrared signal transmission. These features make it easier to control your entire system remotely.
This Niles multi-zone amplifier has multiple sets of inputs and outputs, so signal can be passed along to additional amplifiers in other locations.
There are plenty of two-channel power amps to choose from. The Russound P75 and AudioSource AMP100VS are customer favorites that provide solid power for two speakers, or two pairs in an A/B configuration.
As you might guess, there are lots of ways to configure a multi-channel system for whole-home audio. (To get the full scoop, read our in-depth article about how to power a multi-room system.)
The versatile Russound D850 provides a robust 80 watts per channel for up to eight 4-ohm speakers, and offers control of four separate zones.
Audiophile brand NAD offers 4-channel and 8-channel multi-zone amps that are perfect for adding surround channels to a home theater system or powering music zones in a multi-room audio system.
Accessories to round out your system
You'll need a strong supporting cast to help your system achieve greatness. Take a look the following:
- Elegant and sturdy equipment racks from Solidsteel
- Audio cables from top brands like Audioquest and McIntosh
- Power protection from Panamax, Furman, SurgeX, and others
Need help designing your system? We can do that
Setting up your ideal home system might require a little help from a knowledgeable pro. Call, email, or chat with us today, and we’ll help you get started.
Our expert Advisors know the gear inside and out. Your Advisor can send specific Crutchfield pages to your screen, saving you a lot of browsing time. You’ll get a shopping cart loaded up with everything you need.
Better yet, free lifetime tech support is included with your Crutchfield purchase.