Amplifier schematic diagram

[Earl Talatala]

Hello. I'm a 18 year old student and we need to build an ampifier as our project. Now my problem is, I don't know how to do it by scratch. So if you have an schematic diagram of an amplifier or if you can help me build one, please reply below. Thank you and have a good day.

 

Btw, our amplifer should be as simple as it could get. Maybe max of 2 speakers and a potentiometer for bass, treble, and volume. Again, thank you

 

[KenjiUmino]

18 minutes ago, Earl Talatala said:

Btw, our amplifer should be as simple as it could get. Maybe max of 2 speakers and a potentiometer for bass, treble, and volume. Again, thank you

 

that's not very simple - you'd have to include some sort of preamp stage that handles bass and treble equalisation. 

 

but how in depth does this project have to be?

 

if the goal is to simply get something running where you can connect a line level source to one end of a black box and a pair of speakers to the other, it's easy

 

you can buy kits that are pretty much ready to go - slap a heatsink on the amp ICs, supply DC voltage, wire some input jacks to it and you are good. 

 

they come preassembled

 

or as a DIY kit with all the parts included 

 

but if the requirement is to actually plan out and create an amp with basic components like transistors and stuff from scratch then this would not pass.

[mariushm]

If you can still get them (they're discontinued, but old stock and clones are available on eBay and other stores) , TDA2050 chips are super simple to use.

They're mono audio amplifier chips and can be powered with either single power supply or split power supply (at least 12v, but recommended 24v .. 40v  or +/- 6v .. +/- 22v

 

The datasheet contains example circuits , see page 4 for split power supply design and page 6 for single power supply design :

 

tda2050_en.CD00000131.pdf

 

There's even websites with projects made with these chips : http://diyaudioprojects.com/Chip/DIY-TDA2050-Hi-Fi-Chip-Amplifier/

 OR http://www.circuitbasics.com/tda2050-diy-amplifier-build-guide/

 

You'll need practically two copies of the same circuit, one for each channel , and ideally you'd use a power transformer with two secondary windings to feed both amplifier boards with positive and negative voltages (split power supply). You'll also need some heatsink for each chip, as being class AB, they're fairly inefficient, at around 70%. 

 

If you want to go with Class D (more efficient but less "pure" sound and potentially easier to power with just let's say 12v from a computer power supply) , then you could check out TPA3125 or TPA3122 , which are also available in DIP packages, so you can quickly make a circuit on a prototyping board

 

TPA3125 : http://www.ti.com/lit/ds/symlink/tpa3125d2.pdf

TPA3122 : http://www.ti.com/lit/ds/symlink/tpa3122d2.pdf

 

Datasheets contain example circuits and explain how to pick components in circuit based on speaker impedance and other things. It's all there in datasheet.

 

And true, none of the above have treble and bass controls ,, there are more advanced amplifier chips which can do that, but they're usually surface mount style (harder to solder if you never did it or if you are a beginner like you seem to be if you ask these questions) and some need to be configured through i2c or i2s or other methods using separate microcontrollers or processors in order to work.

 

Plain volume control is boring and simple, just a potentiometer on the input signal.. stick to that for beginning.

 

If you're in US, Digikey is a good place to shop for parts, here's the audio amplifiers section : https://www.digikey.com/products/en/integrated-circuits-ics/linear-amplifiers-audio/742

 

[Unimportant]

2 hours ago, Earl Talatala said:

Hello. I'm a 18 year old student and we need to build an ampifier as our project. Now my problem is, I don't know how to do it by scratch. So if you have an schematic diagram of an amplifier or if you can help me build one, please reply below. Thank you and have a good day.

 

Btw, our amplifer should be as simple as it could get. Maybe max of 2 speakers and a potentiometer for bass, treble, and volume. Again, thank you

 

Seems rather weird to me, they won't ask you to build a amplifier out of nowhere, what are you studying ?

 

If it's some form of electronics course I don't think the point is to simply slap a chip on a board and call it done. Perhaps they want you to design something out of discrete components yourself with the knowledge you gained trough out your studies ?

[mariushm]

Also check out the site here : http://sound.whsites.net/index2.html

 

Loads of dyi projects, from basic audio amplifiers to very high wattage complex amplifiers.

Here's a lot of headphone amplifiers : http://sound.whsites.net/projects-0.htm#hdp  and here's a lot of regular (power) amplifiers : http://sound.whsites.net/projects-0.htm#pwr

 

 

This channel may also have some useful information : https://www.youtube.com/user/radiofun232/videos

 

 

 

 

[ShredBird]

It would not be hard to build two-channel, non-inverting op-amp with MOSFET current buffer (basically a CMOY design).  However the EQ is a lot harder to build.

[Earl Talatala]

Thank you for all the replies. Sorry I was busy these past few weeks. The idea is to buy a power-amp from a local electronics store and design a pre-amp to filter all the noises coming out of an amplifier