I don't really understand electronics that much, and i need to fix my circuit and make a report about it D:

Here's the only thing i understand :
1. Making a Transistor Active
2. V = IR
3. Kirchoff's Law

Okay so here's what i need to do :
Make a Pre-Amplifier and Tone Control ( with Bass and Treble channel ) for my final project.
# The output has to be able to power a speaker, the speaker impedance is 0.5-4 ohm
# The Input is a standard audio input ( 20 Hz - 20 kHz ), with impedance of 20-50 ohm
# And my friend said if i test it with a function generator the input and output has to be a Sine Wave

And finally i made this circuit ( Pre-Amplifier and Tone Control ).



So after testing it with a phone playing mp3 with an aux, i can't hear anything from the speaker, so i don't think my circuit works. Then i tested it with my
Headphone, surprisingly it worked but the sound is so small and my Tone Control's bass and treble knob also worked. A friend of mine said that my circuit's impedance is too high so it does not match the 3 ohm ( i think ) Speaker.

What should i do? should i make a new Pre-Amplifier? How do i make it? Should i replace something? my professor said that we should probably
make a Voltage Follower ( i don't even know what this is ). I really need your help guys D: having no background in Electrical Circuits, it's really confusing and i have to submit it in 30/04/2018.

Thank you very much for helping me btw i am sorry if my english is bad.

 

A friend of mine said that my circuit's impedance is too high so it does not match the 3 ohm ( i think ) Speaker.

Your friend is correct. I don't see an amplifier stage. There are many possible solutions. Since this is Homework, can we assume that you cannot use an audio amplifier integrated circuit? One IC commonly used in hobbyist circuits is the LM386, but there are many much better chips also available.

A voltage follower is a way to amplify the current (reduce the impedance) of your current project while following its voltage output. You don't need a voltage amplifier, you need more current.

 

Your friend is correct. I don't see an amplifier stage. There are many possible solutions. Since this is Homework, can we assume that you cannot use an audio amplifier integrated circuit? One IC commonly used in hobbyist circuits is the LM386, but there are many much better chips also available.

A voltage follower is a way to amplify the current (reduce the impedance) of your current project while following its voltage output. You don't need a voltage amplifier, you need more current.

Yes my professor said we can't use IC and Op-Amps, and use Transistors. D: Do you have any solutions for this circuit so that it may work with the speaker?

 

I don’t have one but you have all the hints you need to search for one. Simple audio amp, simple voltage follower, single transistor audio amp, that sort of thing.

 

I don’t have one but you have all the hints you need to search for one. Simple audio amp, simple voltage follower, single transistor audio amp, that sort of thing.

How do i make an amplifier so that it matches the impedance of the speaker? i really have no idea and i only have 3 days left D:

 

Hello,

When did you get the assignment?

You might want to read a book on designing amplifiers:
https://the-eye.eu/public/Books/Electronic Archive/Audio_Electronics__Transistor_Amplifiers_Design_Handbook_D._Self.pdf

Bertus

 

How do i make an amplifier so that it matches the impedance of the speaker? i really have no idea and i only have 3 days left D:

You don't need to "match" the impedance, you just need a "low" impedance, so that you can move a larger current through the speaker without collapsing the voltage. I told you what to search for. Did you not find anything?