Sorting through AV marketplaces is confusing. After all, some products labeled receivers also have amplifiers and vice-versa. But what is the difference?
The difference between integrated amp and receiver is their function. Integrated amplifiers strengthen audio signals for playback. Receivers do the work of receiving radio waves, decoding the audio information, and switch video inputs. While receivers and amplifiers often work together, especially in the same box, they are not the same.
Read on to learn more about amplifiers, receivers, and how they differ. There is a lot to unpack here.
Table of Contents
What Is an Amplifier, and How Does It Work?
Amplifiers: A Brief History
Amplifiers transfer music signals and amplify them on speakers. Amplification was a process initially intended for radio. However, as technology advanced and other media devices came to be, the technology has become synonymous with all sorts of audio listening.
The prototype, an electron vacuum tube called the “Audion,” was invented by Lee de Forest in the early 1900s. Engineers Irving Langmuir and Edwin Armstrong refined the invention by creating an airless vacuum tube with three components called the triode. The positive terminal was a platinum plate, and a cathode served as the negative terminal. A platinum grid was the mediator.
We would refer to the platinum grid as the ‘input’ and the cathode as the ‘output’ in current terms. The cathode takes on power from heat, causing negatively charged electrons to move to the platinum grid. Once the electrons arrive at the platinum grid, the current of the flow breaks and changes the electrons’ voltage, and amplification occurs.
Amplifiers needed time to become safe for use. The first, smaller device that made this possible was the transistor in 1947. However, modern amplifiers work similarly to their founding ancestors. These devices receive tiny electrical signals from an input device, like a TV or CD player, and output an amplified version of the same signal.
Amplification does not happen all at once. Mic and instrument level signals are too weak to be processed by one amplifier alone. A preamplifier amplifies these signals enough to get them to line-level, enough for a power amplifier to translate to stereo-level sound. These stepping stones to amplified audio are known as gain stages. The preamplifier is your music’s first gain stage on its way to the main stage.
Are preamplifiers a prerequisite for the best sound quality possible? Not exactly. They are a necessity, for sure, and will improve the best aspects of your sound system. However, preamplifiers will not resolve pre-existing sound issues. More importantly, adding multiple preamplifiers will not make your sound better. Every time a signal amplifies, the audio builds up more noise. Plugging one preamp into another will result in a lot of distortion.
You may assume that preamplifiers all work the same. Well, that is not true in the least. There are various flavors of preamplifiers at an audiophile’s disposal. However, the two main types are clean and colored preamplifiers. Clean preamplifiers replicate sound as clearly as possible with no alterations. Colored preamplifiers, on the other hand, characterize the sound with harmonic distortions. This coloration can significantly enhance your music.
Tech specs for AV products are intimidating. However, most audio engineers break them down into simpler qualifiers. Here are some qualities that will make a massive difference in a preamplifier:
- Channels: The number of channels you need is contingent on how many speakers you are using. Usually, one speaker needs one channel. The average stereo amplification system (1 preamp + 1 power amp) only supports two channels. If you require support for more channels than that, check the stats of the preamp.
- Type of preamp: Remember when we went over clean and colored preamps earlier? The indicators for each—FET and tube preamps are commonly colored. However, solid-state models, especially those without transformers, tend to be clean.
- Maximum gain: Different microphones require different amounts of gain. On the one hand, condenser mics can get by on 30dB-50dB of gain. On the other hand, low output/high-impedance mics (think old dynamics and ribbon mics) require 50dB-70dB.
- In-line processing: You will better understand these qualities by checking your channel strip’s equalization and compression values.
- I/O (Input/Output): This is relatively straightforward. You want to make sure you have enough support for all of the devices you plan to use with the preamplifier. However, there is also the opportunity to consider more advanced features, like onboard digital conversion for more complex amplification systems.
As you recall with gain stages, preamplifiers are the first gain stage of an audio signal. Power amplifiers, on the other hand, are the last. This stage is the final stop before the sound comes out of the output device.
You can take a look at Electronics Hub: What is a Power Amplifier? Types, Classes, and Applications for reference.
Notice how the signal makes multiple stops between the microphone and the speaker? In this case, the preamp and voltage amp strengthen the audio signal. The tone and volume control determines the qualities of the amplified sound. The power amplifier follows these instructions and amplifies the signal for playback on the speaker.
Note: For this article, we will not be focusing on voltage amps, so don’t worry too much about knowing what one is. Unless, of course, you are interested in the topic.
It is easy to assume that amplifiers are clunky appliances only used for theaters and concert halls. However, power amplifiers and their earlier stage predecessors can exist in everyday audio products like hearing aids, headphones, and your home speaker system.
Additionally, power amplifier circuits are not a one-size-fits-all setup. There is a multitude of power amplifier categories. These categorizations use output and operational qualities to define themselves. The power amplifiers we are focusing on, audio power amplifiers, come in classes A, B, AB, or C.
What Is an Integrated Amplifier?
As you may have noticed, an amplification system contains multiple parts. For our purposes, an audio input requires at least two amplifiers (a preamplifier and a power amplifier) to make signals strong enough for audio output. However, how these two components are set up concerning each other varies.
You can take a look at TurboFuture: Wattage for Stereo and Home Theaters Explained for reference.
There are several ways to configure an amplification system. You can use two separated components, as the first diagram exhibits. On the other hand, you could also keep both the preamp and power amp in the same console, known as the integrated amp.
Considering the convenience of an integrated amp, using a separate preamp and power amp may seem antiquated. However, some audio fanatics prefer a separate system due to more control over noise reduction and sound quality.
Now here is where things get dicey: receivers also contain integrated amps. But if receivers have integrated amps, aren’t they both the same thing? Nope. An integrated stereo amplifier, for example, works differently from an integrated amp for an AV receiver. Plus, the function of a receiver is entirely different from the integrated amplifier it utilizes.
What Is a Receiver?
Receivers: A Brief History
Modern wireless technology owes a lot to Guglielmo Marconi, who established a business based on wireless communication at the end of the 19th century. He noticed the need for wireless communication in an age filled with turmoil. One disaster, in particular, the sinking of the RMS Titanic in 1912, proved how vital, if not life-saving, the technology could be.
Early radio messages were simple dots and dits, like the sound of an antique telegraph. Their quality was behest to many factors, like atmospheric conditions, the strength of the transmitters and receivers, and operator aptitude, among other things. To strengthen their reach, Marconi created a network of stations on land and ships that sailed the seas.
Later on, Lee de Forest, who we discussed earlier, invented the Audion vacuum tube. However, his understanding of the technology, or lack thereof, and his business failings stifled its potential.
Edwin Armstrong helped the technology reach its full potential. His studies of the vacuum tube resulted in the regenerative receiver. Armstrong’s accomplishments got him noticed by the US Army, who used his radio expertise to facilitate combat communication during World War I.
The major game-changer in radio technology was born from the professional relationship of Armstrong and David Sarnoff, a rising star of the American Marconi Corporation. Sarnoff’s vision for radio surpassed Marconi’s initial ambitions. Instead of two-way radio communication, Sarnoff envisioned radio reaching a vast net of parties. This vision resulted in a significant landmark for radio, the broadcast of the Dempsey vs. Carpentier boxing match in 1921.
Radio technology remained relatively the same throughout the twentieth century until the introduction of analog-to-digital conversion in the 1970s. This process has matured throughout the 1990s and into today. ADC is why we can experience digital radio and television.
Today, digital signals translate to analog as well. Products featuring digital-to-analog converters allow music lovers to connect their music streamer to primary analog stereo amplifiers.
How Does It Work?
In the home theater world, we usually talk about receivers in the context of AV receivers. However, as its history suggests, receivers are a cornerstone of radio communication. Of course, if receivers are receiving messages, where do those messages originate? Radio transmitters send these messages over sine waves to be picked up by the receiver. Therefore, understanding both transmitters and receivers is vital.
Transmitters (radio receivers in the same linked article) use their components to send audio, visual, and digital information over radio waves. Let’s take a look at each element in detail:
- Power supply: Like any electronic device, a transmitter needs power to operate. Having an electrical power source is essential to its function.
- Oscillator: The oscillator creates a fluctuating current at the frequency the transmitter sends its information. This sine wave is the carrier wave.
- Modulator: The modulator applies information to the carrier wave to be consumed by the receiver. There are two ways to add this information. AM, or amplitude modulation, uses slight changes in the intensity of the carrier wave. On the other hand, FM, or frequency modulation, makes subtle changes in the carrier wave frequency.
- Amplifier: Radio waves need the power to travel and get picked up by receivers. Therefore, the carrier waves get amplified to strengthen the broadcast.
- Antenna: The antenna converts the carrier waves to radio waves and sends them out to the world.
Radio receivers pick up the many radio waves that travel in their vicinity. However, they use their tools, like antennas and tuners, to focus on specific waves. Then the receiver takes the audio information from those waves, amplifies them, and sends those waves to the speaker. For a further part breakdown:
Antenna and Amplifier
The antenna is a length of wire that picks up radio waves. How does this happen? When radio waves hit this wire, an alternating current carries through the antenna.
But radio waves are not strong enough to be interpreted on their own. They need the assistance of a radio frequency (RF) amplifier to strengthen the signal. This amplification makes the waves suitable for consumption by the tuner.
The radio receiver needs a method to discern radio waves. Otherwise, it would play all of the stations at the same time. That is where the tuner comes in. If you have ever changed stations on a radio, then you are familiar with a tuner.
But how does a tuner single out that one radio wave for the receiver? The tuner contains two parts: an inductor and a capacitor. The inductor is usually a coil, while the capacitor is a component that stores energy in an electrical field. Both work in tandem to create a circuit that resonates at specific frequencies. The frequency at which the circuit resonates is the resonant frequency.
The resonant frequency adjusts with changes to the inductance in the coil and capacitance in the capacitor. Once the resonant frequency gets set, the circuit blocks out any waves above or below the resonant frequency. Simpler tuners set their resonant frequencies with the twists of a coil. Yet other tuners use variable capacitors, or tuning capacitors, to establish the resonant frequency.
It is important to note that the receiver’s job does not end when it receives a radio wave. The information from the wave still needs to be decoded. Detectors use different technologies, depending on the type of transmission (AM or FM), to dissect the wave’s information to send to the amplifier.
We already reviewed audio amplifiers in detail above. So you should know that they amplify the signals detected from the radio waves to play on a speaker. Audio amplification is the final step from the radio transmission to your speaker.
How Do Integrated Amps and Receivers Differ?
Integrated amplifiers and receivers differ by their functions. An integrated amplifier amplifies audio signals for stereo play. A receiver, on the other hand, is what picks up and decodes that signal. While many receivers feature an amplification system, that does not make the two products the same.
When you are shopping, you may notice two standard varieties of integrated amps: stereo amplifiers and AV receivers. Both often include integrated amplifiers. However, that does not mean they amplify the same way. It also does not mean they can play the same types of media.
Stereo amplifiers cater exclusively to audio devices, mostly analog. These devices are physical, like CDs, cassette tapes, and vinyl. They usually do not have an FM receiver, although they sometimes pick up digital radio. They also only support up to two speaker channels at a time, focusing on warmth and quality over surround sound’s theatrics.
AV receivers, on the other hand, manage a complete home theater experience. They tend to support as many devices as possible: audio and visual. Additionally, they receive radio signals from an FM transmitter. Speaker amplification is more dispersed, focusing on creating an enveloping theatrical experience on systems that include at least half a dozen speakers.
If the comparison of stereo amplifiers and AV receivers was confusing for you, it is reasonable. Integrated amplifiers and receivers rely so much on each other that discerning the two is difficult. So when you are shopping for AV equipment, always check the features. Consider how many speakers you are powering, what inputs and outputs you need to support, and what additional components you may need when you buy a particular product.
In short, integrated amplifiers and receivers often help each other achieve specific tasks. However, the jobs they perform are entirely different. Integrated amplifiers strengthen audio signals. Conversely, receivers receive audio info from radio waves. They get included in the same product sometimes, like AV receivers. Still, they get sold separately as well.
It’s important to match features with your expectations, as recommendations will differ depending on what you are trying to accomplish. Always do your research when investigating these devices to find what is right for you.