Portable Guitar Amplifier - DIY





Introduction: Portable Guitar Amplifier - DIY

About: Sam Technology Professional is an independent educational organization teaching, developing & Inventing Electronics Projects. More at: http://samtechpro.blogspot.com & http://youtube.com/samtechpro

Welcome To "Sam Technology Professionals"
Hi Guys..!!
This is a portable guitar amplifier with some exclusive function. It gives you clean sound, bright & loud sound and distortion guitar sound. Even if you connect a semi acoustic guitar it will work as it do. It is good for high impedance pickups and microphones as well.

Details :

It is based on two IC "LM386" and some capacitors and resistors. It works fine. Its is easy to build and you can do it easily within 30mins.
Components Required:
1 - Resistor 10 Ohm
2 - Capacitor    0.047uf  [Code = 473J or 473k]
1 - Capacitor    100uf     [ Voltage = 25v or 50v] 
2 - Capacitor    10uf
1 - Capacitor    220uf     [Voltage = 16v or 25v]
2 - IC LM386                   [Its a Low Voltage OP Amp]
1 - Small Speaker
1 - Potentiometer 10K Ohm   [Linear or Audio But i will prefer audio first]
1 - LED (use it in series with a 100 Ohm resistor)
1 - DC Power Jack [Or you can use a 9v battery clip if you want to fit the battery in it.]

Beside these components a piece of pref-board and box to fit the circuit in are also required.lol

If you have any question then ask me in comments. I promise to reply your every comment.
Build it now..!! Have a wonderful Day..!!



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    19 Discussions

    I've made the circuit but there a distortion in the speakers, I can't seem to get rid of. How do I correct it. I'm using a 2.5W, 8Ohms speaker

    3 replies

    distorted sound sometimes comes because of the gain cap that is 10uf between pin1 and 8 of ic386. try adding a 10k resistance in series with 10u caps for both ic. this will reduce the boosted gain. now replace the cap which is between positive rail and gnd with 330 or 470uf caps at 16v. you'll observe the noise is gone. A perfect IC original comes from Japan that doesn't have these issues. but at least you almost fixed the ordinary ic;)

    I'm interested in building this but I'm curious how to get the most distortion out of the circuit ? I built some night fire mini amps before and they don't have enough gain that I'm trying to achieve. Can you help me figure this out ? Also to get the volts up to 12 without a power supply can I simply wire a 9volt into two AA batteries in series ?

    I have a better idea to have more ouput power so we can drive larger speaker of about 2.5inches also the schematic is so simple that any one would feel relaxed to build that. I'll share it within two days on my instructables.

    And no you should not use AA batteries with 9v supply in order to have 12v. The above circuit and most of the op-amps circuit starts working on 5v. So i think 9v is ok for that you don't need to have 12v special supply. But i would suggest you to keep every suppy because you're gonna need them to test your equipments or you can build your own variable power supply. Have a good day (Y)

    A drawing mistake ha s been corrected. You can now build it.

    another method to power it is to use a battery of 9v that is cheap and of low noise

    that is wrong. the picture contain mistake. i will correct it soon

    There is a long note about it on LM386 datasheet. This
    is called its bridge mode and it makes the power of output double. Also In this way very low signals of input are easily amplified.

    you're right.. i have never noticed what i have done while making.that image in paint. because of some confusions i think. but i will change it. the design of beavis audio doesnt work and if work it has a lot of noise.

    If I wanted to add a standard headphone jack so I could plug my phone in would this be hard to do? Also would your design allow for multiple media inputs at once (e.g. phone and guitar)?


    3 replies

    You can do it easily. Because there is a very less distortion in the output signals as compared to the normal amp circuits based on lm386. Its sound always have distortion. Well you can easily add a headphone jack. You need to add a little circuit at the output like this one:


    This is the link of my website. It will go directly to the schematic required for your headphone jack. Feel free to go. There are several interesting projects related to audio/musical equipments etc.

    I just realized I had not replied to this. Thanks for your help! My project turned out pretty well!

    If you want to just use it as an amplifier to play mp3 from your cell phone then you can just add a headphone jack at the input without changing the circuit


    4 years ago

    How would this look on a breadboard? I already have a mono amp built but its still on the breadboard(I want to test a stereo amp first).

    1 reply

    It looks cool on breadboard when two lm386 are connected. Really looks wonderful. May be a pic of it i have posted on my blog. Well you can easily buid a stereo amp. Follow a simple mono amp circuit. Build two amp. One's input is Connected to the right channel of audio and the other's input is connected to the left channel. And ground is the same for all.