How many different types of amplifiers are there?
We’ve talked about amplifiers in we don’t know how many articles.
We’ve probably mentioned it in at least 50% of our posts.
And since this is the case, we asked ourselves, why don’t we write an in-depth post on amplifiers.
If we were going to write an article on an amplifier, we wanted it to be helpful.
After doing some research, a tuned amplifier caught our eye because it’s something we can educate our audience about and it’s practical.
Anyone wanting to upgrade their amplifier will find this post helpful which is why we wrote it.
Considering most speakers already have an amplifier though, why would anyone buy a tuned amplifier?
WHY A TUNED AMPLIFIER?
A tuned amplifier singles out a frequency range for which it can handle and deny other frequencies.
To understand the significance of this, we need to understand what a frequency is.
A frequency is a sinusoidal wave which gets repeated over and over.
Do you know what the twist with frequencies is though?
Frequencies produce waves, but they don’t produce sound.
OUR ears give us the perception of sound. The problem with this is multiple frequencies distort our hearing.
What’s wrong with multiple frequencies?
Imagine one frequency going at 10 Hz and another one going at 125 Hz.
A Hz is the metric for oscillations. An oscillation is like a pendulum swinging back and forth. 10 Hz is like a pendulum swinging back and forth 10 times in 1 second.
Now imagine 125 Hz.
What do you think is easier to keep track of for the human eye? 10 Hz or 125 Hz?
Now, instead of your eyes, think of your ears listening to 2 different frequencies. One moving at 10 Hz and another one moving at 125 Hz. Your ears will not keep up which is why sound distortion happens when multiple frequencies are involved.
And when multiple frequencies are happening, one of the best amplifiers to deal with this is a tuned amplifier.
TYPES OF TUNED AMPLIFIERS
There are 2 broad categories of tuned amplifiers:
- Small Signal Amplifiers
- Large Signal Amplifiers
Let’s start with large signal amplifiers.
Large signal amplifiers support bigger frequencies which have a large magnitude. An example of this is concert speakers which have to have large bass and treble.
The opposite holds true for small signal amplifiers. But the main difference between these 2 types of amplifiers is there are more different types of small signal amplifiers:
- Single Tuned Amplifiers
- Double Tuned Amplifiers
- Stagger Tuned Amplifiers
A single tuned amplifier has a parallel circuit inside the collector load.
The double tuned amplifier is popular because it has a wide bandwidth. What makes a double tuned amplifier different is it’s tuned differently because of a capacitor on both sides.
Staggered tuning has multiple stages and each have a different frequency. The catch to produce different frequency comes at the expense of gain.
ADVANTAGES OF A TUNED AMPLIFIER
Variable Bandwidth (frequency response)
When looking at an amplifier you want one which reproduces the same audio quality as it’s recorded.
This is an obvious statement, but, to dive deeper into the statement, a great amplifier needs to have the ability to have a great frequency response and it also needs to be able to amplify a frequency signal.
These 2 components make up great bandwidth.
1 factor determines whether those 2 components will be great for bandwidth.
That 1 factor is called “gain”.
Gain is the ability of an amplifier to strengthen a signal by adding energy into it by using the energy from a power supply.
Imagine this, 1 person is pushing a car.
Then another person joins in to push with their body (energy).
That other person is acting like the “gain”.
Combining all these factors is what determines frequency response. The ability of an amplifier to reproduce both bass and treble without turning up the volume is a great advantage of a tuned amplifier.
Radio wave transmission
Besides speakers, another device which uses radio waves is microwaves. What’s great with microwaves is they send a lot of information at once.
In addition to that, they can store lots of data making it easier to send information at a faster pace.
By having good radio wave transmission, worrying about static or sound disruption is futile.
Signal to noise ratio
A good signal to noise ratio is huge for sound quality. It measures how much of the desired signal you’re getting compared to how much background noise is going against it.
The noise portion in a signal to noise ratio can be hissing, popping, or crackling. The underlying noise is similar to a refrigerator.
If you’re fortunate enough to sleep in a living room where it’s freezing cold and is right next to a kitchen then you’ll know what we’re talking about. That sound a refrigerator has is very pleasing (this whole sentence is sarcasm).
Another catch you want to watch out for is turning up the volume when you have a bad noise ratio. Thinking you’ll drown out the bad noise with more volume will only make the bad noise get louder.
DISADVANTAGE OF A SINGLE TUNED AMPLIFIER
One disadvantage of a tuned amplifier is high selectiveness. You have to understand, bandwidth and voltage have an inverse relationship.
A high voltage spike results in a loss of bandwidth resulting in sound disruption.
All this happens because of a Q-factor tuned amplifier circuit.
A “Q-factor” indicates the amplifier has a high oscillation. An oscillation this high means low damping which lowers the energy of oscillations.
APPLICATIONS OF TUNED AMPLIFIERS
We mentioned how tuned amplifiers have radio wave transmission.
Radio waves are used in 2 common applications. One of them is microwaves (already mentioned), and the other one is telecommunications.
Radio waves are the reason why we communicate with people across the country.
We thought it’d be interesting to show you the other applications:
- Video Amplification
- UHF Radio Relay Systems
- Satellite Transponder
- Television Broadcasting
The similarity in all of these applications is all of them have signals which need to be transmitted.
This is why amplifiers are common in electronic devices. But if you want an amplifier that transmits signals better than any regular amplifier, a tuned amplifier is the way to go.
Also, its build and construction are ideal.
HOW AN AMPLIFIER IS BUILT
Have you ever heard of an LC circuit?
If you haven’t, maybe you’ve heard of a tank circuit or resonant circuit which are synonyms of an LC circuit.
The “L” means an inductor and the “C” is a capacitor.
Nonetheless, an LC circuit has multiple functions.
The first one is it acts as a resonator. Earlier, we talked about variable bandwidth also known as frequency response. When purchasing an outdoor speaker, you want a speaker with a great frequency response.
An outdoor speaker which produces both bass and treble without adding volume is needed for outdoor space. The acoustics in an outdoor environment are harder on speakers because there isn’t anything for sound waves to bounce off of.
What a resonator does is make sure your speaker produces a high bandwidth by either selecting or generating a frequency.
Types of LC circuits
- Series LC Circuit
A series LC circuit is when the inductor and capacitor are connected by a series. Visually, it looks like the inductor is on top of the capacitor.
- Parallel LC Circuit
A parallel LC circuit is what it is. Both the inductor and capacitor are parallel from each other.
UP TO YOU
Now that we discussed what a tuned amplifier is, how an amplifier is built, as well as its advantages and disadvantages, it’s up to you whether you want to upgrade your amplifier.
However, whether you do so or not, we wish you get the right audio quality for your listening pleasure.