For most people, a stereo system or a home theater system consists of a receiver to which audio and video sources are connected, paired with a set of speakers.
But if you are interested in high-fidelity audio, you may know that other configurations exist, allowing you to enjoy an enhanced listening experience.
Indeed, rather than relying on what is called an "integrated amplifier" (as in the example given above), some will replace this equipment with two distinct devices: a preamplifier connected to a power amplifier. This is known as a separate component system.
Is your curiosity piqued? In this article, our Fillion experts reveal what a preamplifier is, present its role, and explain how to choose one that meets your needs.
What Is a Preamplifier and What Is Its Function?
Stereo preamplifiers and home theater preamplifiers are devices to which you connect your various audio and video sources (CD player, Blu-Ray player, etc.).
Their role is to provide a certain amount of gain to the signal coming from these sources before transmitting it to a power amplifier. Most preamplifiers therefore feature a switch or buttons to select the source to be preamplified.
Example of a stereo preamplifier: the Rotel RC-1572
Preamplifiers also perform certain sound processing tasks. Furthermore, depending on the preamplifier model, you can adjust the output volume, left-right balance, and tone using various types of controls.
In some cases, a preamplifier can also play a central role in a multi-room audio installation, either through multi-zone audio capability or wireless multi-room functionality. Some can even allow you to stream music directly from Apple AirPlay or Bluetooth-compatible mobile devices, such as smartphones or tablets.
A preamplifier can also be equipped with a USB port providing access to compatible digital multimedia content directly from plug-in flash drives or other compatible USB devices.
The Difference Between a Preamplifier and an Integrated Amplifier
In appearance, a preamplifier is not very different from an integrated amplifier. It is what is inside and on the back of these devices that truly distinguishes them.
The main difference is that a preamplifier must generally be paired with a second device to power a speaker system: a power amplifier. This is why many audio equipment brands produce both types of devices.
An integrated amplifier can, for its part, play the role of both a preamplifier and a power amplifier. It is essentially a 2-in-1 device that can be connected directly to a set of speakers, unlike a preamplifier.
It is for this reason that the connectors featuring on preamplifiers and integrated amplifiers (sometimes also called receivers) differ. Both can be equipped with various inputs and outputs, but the integrated amplifier has speaker outputs, whereas the preamplifier generally does not. The latter will instead feature RCA or XLR outputs used to transmit the audio signal to a power amp, which itself features speaker outputs.
It is nonetheless important to emphasize that a preamplifier could be connected directly to powered speakers.
What Are the Advantages of a Preamplifier / Power Amplifier System?
After reading the first part of this text, you may wonder why some choose a preamplifier/power amplifier combo rather than an integrated amplifier or a receiver.
Here are a few advantages of a separate component system.
Superior Sound Quality Due to a Better Signal-to-Noise Ratio
In an integrated amplifier, the preamplification and signal amplification components are packed into the same chassis.
When the preamplifier and power amplifier are two distinct devices, designers have more freedom regarding electronic circuit design. Thus, they can ensure that signal paths are shorter.
Also, sensitive low-voltage preamplification circuits are not as close to high-voltage amplifier components. Not to mention that the preamplifier and amplifier do not have to share the same power supply. Finally, some preamplifiers are equipped with XLR output connectors, which are even quieter than RCA outputs.
All these factors help reduce interference that can cause background noise.
Great Flexibility
When you choose to combine a preamplifier and a power amplifier, you have the freedom to choose two devices that match your needs even more precisely. You do not have to make any compromises.
Do you need a maximum number of inputs or Bluetooth connectivity? You choose your preamplifier accordingly. Do you need higher output power? Opt for a power amplifier that offers you over 300 Watts.
And if your requirements change at some point, a preamplifier/power amp system will allow you to simply replace the device that no longer meets your needs.
How to Choose Your Preamplifier?
If you want to purchase a preamplifier, you will need to take the time to examine several models from different manufacturers and compare them based on specific points.
Check the Inputs and Outputs Featured on the Device
When choosing a preamplifier, it is recommended to consider the type of inputs and outputs (HDMI, phono, RCA, USB, coaxial, XLR, etc.) featured on the device you are eyeing, as well as their number.
For example, if you are looking for a device simply to listen to music, you do not really need a preamplifier equipped with HDMI inputs and outputs. On the other hand, these will be essential in the case of a preamplifier for a home theater system.
Also, you should know that if you want to get the most out of a turntable, you should look for a preamplifier equipped with a "phono" input, specifically designed to handle the signal transmitted by this device.
As for the number of inputs and outputs, the ideal choice is a device that has enough of them so that you do not have to constantly modify the connections on the back of the device when you switch sources.
Determine the Features You Truly Need
As mentioned previously, preamplifiers can feature several functions such as equalization, Bluetooth connectivity, and compatibility with applications like Apple AirPlay or Google Chromecast.
Since adding these features can increase the price of a preamplifier, you should opt for a device that possesses features you will actually use.
Also, in the case of home theater preamplifiers, do not unnecessarily choose a 15.4-channel preamplifier if your goal is to create a 5.1 system.
Ensure You Choose a Preamplifier That Is Compatible with Your Power Amplifier
Since preamplifiers are designed to be connected to a power amplifier, ensure that these two devices are compatible.
One of the elements to look out for is the output impedance of the preamplifier, which is generally expressed in ohms.
Establish a Budget
As is the case for many types of audio equipment, preamplifiers can feature different quality levels. This is why the price to pay for a preamplifier can range from a few hundred dollars to several thousand dollars.
This price difference is generally justified by notable differences in the quality of the device's components, the precision of adjustments, electrical isolation, and chassis construction, to name just a few.
Remember, however, that it may be worth investing a bit more in a high-fidelity model, as the quality of the preamplifier will have a direct effect on the sound rendering of your stereo or home theater system.
In conclusion, we hope this article helped familiarize you with an audio equipment whose role is often misunderstood and sometimes confused with that of a receiver, a power amplifier, or an integrated amplifier.
To Learn More About Preamplifiers, Rely on the Fillion Experts
If you ever need advice or wish to be guided in choosing a preamplifier, know that our Fillion experts can offer you personalized support so that you can get your hands on a product that matches your needs and budget. So, do not hesitate to contact us or drop by the store for a hassle-free shopping experience that can even include the installation of your stereo or home theater system.
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