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Getting the right equipment to start a home theater can seem confusing when there are so many industry terms to familiarize yourself with. You might have wondered whether you need to buy a receiver, preamp, and amplifier for your home theater, possibly without knowing what they actually do.
Receiver vs. Amplifier vs. Preamp
The critical differences between Receiver vs. Amplifier vs. Preamp are based on their functions. A receiver connects input and output devices, whereas an amplifier boosts a signal so it can be played through speakers. A preamp however, boosts a microphone signal to the level that it can be boosted through an amp.
Here’s a handy table to explain the key differences briefly:
|Function||Receives signals from input devices (DVD player) and sends them to output devices (TV/speakers)||Amplifies variable line signals from input source and boosts them so they can be played through speakers at volume||Boosts a weaker signal (such as from a microphone) before sending it to the amplifier|
|Info||Often contains an amp and preamp, along with other functionality||You need as many channels as you have speakers, and most amps will contain up to 7 channels||Often found in integrated amps or AV receivers|
|Is it necessary in a home theater?||Yes||Yes if you don’t have a receiver||Yes if you don’t have a receiver|
|Cost||Moderate to high||Low to moderate||Low|
I’ll explain the differences between these 3 devices as I go along, but first, it’s worth discussing the actual devices in more detail so that we can understand the differences.
What is an AV receiver?
The AV receiver is one of the most fundamental parts of a home theater system and will usually be the first thing you buy. In short, it acts as the central hub of your home theater and does a number of important jobs.
Firstly, it’s the device that connects everything together. It’s where you hook up your input devices, such as DVD players, games consoles, etc. and your output devices, such as speakers, TVs and projectors. This means that a good receiver should be functional but also easy to use.
If nothing else, a receiver makes it easier to switch between all of your devices. While you don’t necessarily need a receiver in your home theater, it makes sense if you have more than one input device, as it saves you having to manually switch cables every time you want to switch devices.
A receiver really comes into its own when you don’t just have video output devices. For example, if you have a record player, then connecting it to a receiver not only saves you having to unplug everything, but also automatically switches your speakers from surround sound to stereo.
This is another major function of a receiver: it gives you master control over your audio settings. Along with volume, a receiver will allow you to change EQ settings, surround sound modes, and much more.
Does a receiver contain an amp?
As I mentioned, one of the main jobs of a receiver is to supply the audio signal to your speakers. By definition, this means that it contains an amp, as this is needed to boost the input audio signal so that it can be received by all speakers.
Similarly, some receivers may also contain a preamp depending on its functions. A preamp simply boosts weaker signals so they can be picked up by the amplifier, but this isn’t always necessary.
A home theater receiver will generally contain 5 channels, but some will have 7. Considering a receiver is designed for surround sound systems, it makes sense that it would have enough channels for this function.
What else can a receiver do?
While these are the main functions of a receiver, they often have a number of other functions that are of varying benefit in a home theater. These include:
- Decoding digital surround sound formats from the input source so they can be properly played on the speakers.
- Works as the central interface for your home theater (possibly though a mobile app). Many also have dedicated LED screens so you can adjust settings.
- Receivers also contain a digital radio tuner, allowing you to connect to digital radio.
One important thing to bear in mind is that many receivers have a signal-processing mode. When this is applied to video signals, it can sometimes result in a loss of picture quality, but this isn’t always the case.
From my personal experience, I’ve found this is most often the case when working with UHD signals. However, it can be easily fixed by using the signal bypass function that’s found on every receiver. Doing this will stop the receiver from processing the image, making it more faithful to the original signal.
What is an amplifier?
In basic terms, an amplifier is a device that turns a low voltage signal enough one powerful enough to power speakers. Amplifiers aren’t unique to home theaters but are found in any device with speakers. However, the power of an amplifier will vary depending on its purpose.
The second function of an amplifier is just as important: it allows the user to collect multiple signals before converting them to a line-level signal. Line-level signal refers to the signal that’s sent to the speakers, and so is the level that all input signals need to be at.
In short, a receiver is an amplifier but not all amplifiers are receivers. The amp’s basic job is to boost signals so they have enough gain to play through speakers. Anything else is considered an extra function and is more likely to be found in a receiver than an amplifier.
Amplifiers can be split into 2 major categories:
- Power amplifier. This is simply an amplifier on its own that boosts input signals for speakers.
- Integrated amplifier. This type also contains a preamp, meaning it can boost signals and add enough gain to be played through speakers.
Do I need an amplifier in my home theater?
As we’ve established, there are several differences between a receiver and an amplifier. So does this mean you need both in your home theater? The answer to this will largely depend on your setup.
The short answer is that providing you have a good receiver, you shouldn’t need an extra amp too. All receivers contain an amp, so providing it has enough channels for your speaker system then you should be covered.
However, this won’t be the case if you have speakers that require a lot of power, or plan on using more speakers than your receiver can handle. Connecting power-hungry speakers to a receiver can cause it to overheat or break down, so this is when an amp comes in handy.
Similarly, if you want to connect extra speakers to your system, or have a very large room to fill, then you might need an extra amp to boost the signal. There isn’t a blanket rule for this kind of setup, so this handy guide should help make things easier.
The bottom line is that you’ll have much greater success matching your equipment from the start. For example, if you’re buying a set of high-power speakers, then ensure your receiver has enough power to handle them.
There are plenty of forums where people discuss these issues, so look them up before you start buying. Also, speakers will generally tell you how much power they need, so pay attention to this information.
What is a preamp?
A preamp is one of the more ambiguous parts of a home theater setup. At the most basic level, a preamp takes particularly weak input signals and boosts them so they’re in line with the other signals being processed in the amp.
The best example to explain this is recording equipment. A microphone has such a weak signal that it’s referred to as mic-level, which is considerably weaker than instrument-level signals.
All of these signals need to be boosted to a line-level signal, which is then boosted by the amp and sent out to speakers. This is what a preamp does: it boosts the signal to the right level for the amp.
Therefore, when choosing a preamp, it must work in line with your amplifier. The devices must have similar power levels so they don’t interfere or create unnecessary feedback or signal distortion.
Preamps come in 2 versions:
- Active preamp. This requires an external power source, and so by extension can power speakers too.
- Passive preamp. This has no external power source and so can only boost the signal enough to send it to the amplifier.
It’s most likely that you’ll only encounter passive preamps in a home theater context, although, as we’ve established, you shouldn’t really need one anyway if you have a receiver.
Similarly, an integrated amp already contains a preamp, and both components are designed to work well together. If you decide to go with an amp for your home theater, then I’d only recommend considering integrated amps.
What else does a preamp do?
Along with boosting weaker signals, a preamp has to modify the sound quality in line with boosting the volume. Without a level of audio processing, the signal received by the amplifier would be far too muddy and contain too much distortion.
Turning up the volume of a signal also increases the background undesirable noise. Similarly, it affects the noise floor, which is the total sound of all unwanted noise on your input signal. In simple terms, this isn’t a good thing.
Realistically, preamps aren’t something we need to concentrate on much in home theaters. They’re much more common in the recording world, which uses more devices like microphones, but it’s still useful to know what they do.
Differences between an amplifier and a preamp
The key differences between an amplifier and a preamp can be broken down as follows:
- A preamp is necessary for boosting signals so they can be picked up by the amplifier
- The amplifier then boosts the signal so it can be received by all speakers in the circuit
- A preamp performs some level of audio processing to remove background noise, whereas an amplifier doesn’t
- An amplifier is much more important in a home theater, but a receiver will contain both, meaning you shouldn’t need to buy either
In short, a preamp can be seen as a smaller amp (the clue is in fact in the name). In a home theater system it won’t be one or the other, but would be both in replacement of a receiver. However, if you buy an integrated amp then you won’t need to think about buying both.
Sound quality comparison
Sound quality proves somewhat difficult to compare in these devices because, while they boost signal, they largely have little impact on its audio quality. However, there are ways we can compare the devices’ impact on overall sound quality.
The bottom line is that the poorest quality device in the system will have the biggest impact on sound quality. It doesn’t matter whether this is the preamp, receiver, or amplifier, the weakest link will be your issue.
When it comes to a receiver, there’s not much to say about sound quality. It contains all the parts needed to boost and process audio signals, so should perform fairly well. That said, be sure to invest in a good quality receiver if you want good quality audio.
The preamp will have more impact on overall sound quality than the amplifier, but this is because it does a certain level of audio processing before sending the signal to the amp.
At the most basic level, the amp should simply boost a signal so it can be sent to the speakers. Therefore it shouldn’t have any impact on sound quality, providing it’s a good quality device. A low-end amp may very well add its own feedback or distortion to a signal if it’s not up to the job.
However, you do need to balance your amp and preamp if you’re not investing in a receiver. The preamp must have the correct volume control and output impedance for the amp, but the amp must have the right level of sensitivity for the preamp.
In addition, the amplifier must have enough power and the correct impedance for the size of the room and number of speakers in the circuit. A good amp is much more important than a good preamp, but you should aim to balance the quality.
The much more sensible option in a home theater, particularly if you’re looking to get the best sound quality, is simply to invest in a good receiver. This contains all the necessary signal boosting equipment, and, more importantly, it’s all designed to work properly together.
When are separates better than a receiver?
In the home theater world, the term used to refer to the devices found in a receiver is separates. So this means that a system using a preamp and amp is a separates system. When is this a better option?
A receiver is a good choice if you have several input devices that you would otherwise be constantly switching between. This is particularly the case if you’re going to be watching TV and movies over other types of media.
However, if you’re a dedicated audiophile and plan on listening to music as much as watching media, then a separates system might be the better choice. It gives you a much “truer” signal while also getting the most from your music.
However, the main drawback here is that you’ll need to manually switch between input devices. If you only have one TV device (such as a games console) and then a music device, this shouldn’t actually be too much of a problem.
Your other option is to buy cable switchers, but these can often be more trouble than they’re worth.
A receiver is also the better option for those new to the world of home theaters. It contains all the necessary parts to get started and does a lot of the work for you, so is a more sensible option.
Switching to an amplifier system is better for those with more knowledge of AV equipment. For starters, it requires more manual setup, along with more pieces of equipment. Conversely, switching to a separates system can make quite a good project for the home theater pro.
Pros and cons of receiver vs. amp and preamp
When it comes to building your home theater system, it’s best to work out what you want before you start buying. You should choose equipment based on your needs, your level of expertise, and your budget.
For the purposes of this comparison, we’ll be considering a receiver-based system against a separates system, which effectively translates to an amp/preamp system.
The pros and cons listed here aren’t exhaustive, but are meant to collect the information given in this article in a more coherent way that should help you to decide which is better for your home theater.
Pros and cons of receivers
- Receivers will generally be the less expensive option because they allow you to buy all the equipment in one box.
- The main benefit of receivers is that they contain all the necessary components to get started, along with multiple input options and support for at least 5 channels.
- A single receiver will take up considerably less space than all the other components fitted separately.
- The components found in a receiver will generally be lower quality than if you bought them separately. Much of this sacrifice is found in the amplifier, meaning it might not be able to handle powerful speakers.
- Similarly, you have to replace the whole unit when upgrading or replacing broken components. This can feel like a waste of money if everything else is working fine.
- A receiver might not offer the level of functionality expected by a true audiophile.
Pros and cons of amp/preamp system
- You have complete flexibility over what goes in to this system. This means you can exclude certain functions you don’t need and focus on building a system that meets your exact needs.
- It’s much easier to upgrade this system because you can simply swap out the piece you no longer want.
- Although more expensive, you can generally expect a longer lifespan from a separate system because of this greater level of flexibility.
- A separate system will be more expensive because you need to buy all the components individually.
- Similarly, you have to invest in components of comparable quality; meaning overall sound quality is more greatly affected by your budget.
- A separate system will take up more space because each component is a full unit rather than being integrated into a single pack.
- A separate system might become too confusing for someone not familiar with audio equipment, making a receiver the easier option.
What this boils down to is that there isn’t a single answer that fits everyone. That said, 9 times out of 10 I’d recommend going with a receiver for your home theater, simply because it’s the easier option.
Also, don’t be too put off by the idea that the components are of a lower quality than if they were bought separate. A high-end receiver will still provide good audio quality, and the differences would be negligible unless you were truly listening out for them.
Some final thoughts
When it comes to comparing receivers to amplifiers and preamps, the differences are found in their functionality. A receiver contains both a preamp and an amp, and they can basically be split into whether you want an integrated or separate system.
When deciding what to buy for your home theater, decide based on your needs. If you have more than one input device then a receiver makes sense, but if you want a truly customized home theater system, then an amp might be the better option.