Introduction: Portable Guitar Amp With Distortion / Bass Amplifier - 9v / LM386 IC
This is a really simple portable guitar amp project you can complete in an afternoon ; with the parts you need at hand. I used an old surround sound speaker as my enclosure, and used the speaker. The unit also has 5 tone settings to allow you to go from clean to gritty.
NOTE: if you are thinking about building one of these, see my newest addition first based on the 'Little Gem' amplifier, using a few more parts. It sounds much better.
https://www.instructables.com/id/The-Little-Gem-Mini-Amplifier-Guitar-Amp-/
Step 1: Parts List / Wiring Diagram
The diagram below explains this build in detail. If you want 5-mode distortion, then you simply use the dip switch in place of the SPST switch on the 2.2uf-10uF capacitor. Remember that the speaker you use will make all of the difference in how clean your new portable guitar amp sounds. Mine sounds pretty clean, I achieve this by isolating jacks and components from each other, and I hot glue the audio lines and PCB wiring to avoid leakage.
Parts List:
Enclosure: I used an old surround sound speaker as my enclosure. You could make this unit into a box and use as a 'head' for speakers in mini-cabinets too.
9V Battery
9V Battery Clip
Input / Output Jacks 1/4 Mono
SPST Switch OR Dip Switch w/ 5 settings
PCB / Board material
LM386N IC
8 Pin IC socket (optional)
4.7uF Capacitor
10uF Capacitor
100uF Capacitor
470uF Capacitor
[optional - for multiple distortion modes]
0.01 capacitor
2.2 uF capacitor
00.47 capacitor
4.7uF capacitor
10uF capacitor
+ higher cap values = heavier distortion
Step 2: Putting It Together ...
This is a pretty simple PCB for making it all work - I think the power output is a 1/2 a watt. Follow my wiring diagram (photo 2) to put it all together.
Some notes:
I make a daughter board for my dip switch and extra capacitors for my multiple distortion modes.
I usually use shielded audio cable for the inputs and outputs to cut down on any feedback / buzz ; and a socket for the LM386 IC (not necessary) - just in case it gets toasted.
The LED for on/off is out the front [ use a 470ohm resistor between +9 and your on off switch ]
Battery location could be internal, but they get ate so I mounted mine externally. A 'Supercap' battery is another idea -- (DIY 9v rechargeable) or some other rechargeable battery as this device runs up to 15v.
Dip switch could be replaced with a 6-position selection switch / or other
Gain / Volume POTs could be added
Step 3: Finishing Up
You can build this into anything, but I decided an old surround sound speaker enclosure would work best (for being dropped, etc..).
I'll probably add these in the near future:
Volume / Tone Pots
A distortion unit clone on a foot switch (VOX tone bender clone)
Rechargeable Battery (of some kind) & built in charger / car charger
6-way tone selection switch
More stickers
A handle
PCB mounts
3 People Made This Project!
- Mass1mo made it!
- Erik-Mattson made it!
- MehmetÖ2 made it!
71 Comments
3 years ago
How long does it last with the 9V battery?
4 years ago
Where to connect the LED?
5 years ago
Could a speaker be put on the output instead of a jack to output the sound?
Reply 4 years ago
yes, but only use a small speaker
4 years ago
Is it possible to use ceramic caps instead of electrolytic
6 years ago on Introduction
What's the role of the C2, C3 and C4 capacitors?
Reply 6 years ago on Introduction
C4 filters input audio signals and C2 filters output signals. And C3 filters the Vcc coming from battery.
7 years ago on Introduction
Great tut, but why use a switch between pins 1 and 8???
A pot works much better and provides more tonal flavors.
For added distortion, use clipping diodes. These can be strategically inserted and still use the switch to give different clipping options. Also, a simple tone stack works great in the Little Gem. You new guys should start with the BMP stack...then move up to the 3-Knob versions ;)
7 years ago on Introduction
how do i know where i can put capicators - and + because it isn't clear for me,
Reply 7 years ago on Introduction
Look at the schematic.
If you can't read schematics--go to runoffgroove dot com for the perfboard layout.
7 years ago on Introduction
how many voltage in the capacitor of 4.7uF Capacitor, 10uF Capacitor , 100uF Capacitor, and 470uF Capacitor. Please reply ... tnx !
Reply 7 years ago on Introduction
Anything above the rated piwer source. I typically use 35 or 50v caps.
7 years ago on Introduction
how to add volume, bass and treble control?
Reply 7 years ago on Introduction
You build and add a tone stack.
7 years ago on Introduction
OK so I completed the circuit .. Everything works great. But I dont know why but the amp cant pick the B string on my guitar . Is it because of the pickup or something else ?? FYI This is my first guitar effects project.
Reply 7 years ago on Introduction
It's your guitar. If the amp is putting out a signal on all other strings--the amp is fine.
7 years ago on Introduction
Great 'ible. Built one, and it wasn't working well enough with a piezo pickup. Found I could use a MPF102 as a buffer, and if you replace your switch on the 10uf cap with a 1-2k resistor, you can have variable gain!
8 years ago on Introduction
Hi! That's a great job you got there.
Now, I'm planning to build the amp, but I'm having a hard time figuring out how I could add a volume pot... Can you please enlighten me?
Thanks
Reply 8 years ago on Introduction
you can put a few 5k potentiometer, to connect you have to look at it from the front and pin 1 is ground, pin 2 goes to the output of the circuit, and pin 3 to jack TIP
8 years ago on Introduction
the polarity of the capacitors is it right negative?