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



Comments

author
FreddyR16 made it!(author)2017-02-09

Where to connect the LED?

author
Erik-Mattson made it!(author)2016-11-28

Made it (breadboard). And it's a pretty cool little amp for sittin' and jamming. Added a genuine on/off switch, volume knob, and power indicator LED. \m/

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author
egyedia made it!(author)2016-11-29

I like the extras you added to this amp!

I am planning to build this together with my son for his mini guitar. I am not a total newbie, but I am not a hardcore circuit builder neither. Could you just indicate where your additions should be mounted?

I am also thinking about adding the support for dual power (battery vs external power supply). A headphone output (which would switch off the speaker) will be nice as well :)

Do you have any suggestions regarding these?

Thank you.

author
hfresco made it!(author)2016-02-10

Could a speaker be put on the output instead of a jack to output the sound?

author
owatson made it!(author)2016-07-26

yes, but only use a small speaker

author
Mehmet%C3%962 made it!(author)2016-06-10

thank you. i did this circuit and it works well :=)

amp.JPG
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Jonko123 made it!(author)2016-05-12

Is it possible to use ceramic caps instead of electrolytic

author
Guii made it!(author)2014-05-12

What's the role of the C2, C3 and C4 capacitors?

author
samtechpro made it!(author)2014-12-19

C4 filters input audio signals and C2 filters output signals. And C3 filters the Vcc coming from battery.

author
avianoguitarist made it!(author)2014-02-13

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 ;)

author
djurenas made it!(author)2013-05-13

how do i know where i can put capicators - and + because it isn't clear for me,

author
avianoguitarist made it!(author)2014-02-13

Look at the schematic.
If you can't read schematics--go to runoffgroove dot com for the perfboard layout.

author
cholo123 made it!(author)2013-05-16

how many voltage in the capacitor of 4.7uF Capacitor, 10uF Capacitor , 100uF Capacitor, and 470uF Capacitor. Please reply ... tnx !

author
avianoguitarist made it!(author)2014-02-13

Anything above the rated piwer source. I typically use 35 or 50v caps.

author
pmakakatok made it!(author)2013-08-18

how to add volume, bass and treble control?

author
avianoguitarist made it!(author)2014-02-13

You build and add a tone stack.

author
blinkme made it!(author)2013-10-22

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.

author
avianoguitarist made it!(author)2014-02-13

It's your guitar. If the amp is putting out a signal on all other strings--the amp is fine.

author
jsawyer made it!(author)2013-08-29

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!

author
NunoMorna made it!(author)2012-12-18

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

author
pogodike200%21%21%21 made it!(author)2013-01-18

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

author
pogodike200%21%21%21 made it!(author)2013-01-18

the polarity of the capacitors is it right negative?

author
ghosty37 made it!(author)2012-01-14

Hy, I made it to. It works very well. Thanks.
I replace your dip switch by a rotary switch.

I add volume pot(100k lin.), like in another project I did at the same time.
https://www.instructables.com/id/Distortion-Pedal-With-Stutter-Effect/

What type of speaker did you use?

Mini guitar amp large.jpgMini guitar amp pcb.jpg
author
jorence made it!(author)2011-12-22

wat r the voltages of the caps??

author
bgondes made it!(author)2011-11-09

how to make the sound distortion is long?????

author
volney made it!(author)2011-07-05

Great instructable! But how do i connect an on/off switch and LED?

author
jimdkc made it!(author)2011-08-15

This circuit needs no on/off switch. The way the input jack is wired, the ground circuit to the battery is completed when you plug in your guitar. The sleeve of the plug shorts the ring and sleeve connections on the jack. (The input jack is actually a stereo jack, not mono.)

You could put an LED from the + battery terminal, through a current limiting resistor, to ground.

author
andrezfen made it!(author)2011-07-31

i followed your circuit and it is successful. than you capthook :D

author
coolguy2015 made it!(author)2011-04-12

for volume control how much k ohms of pot should i use?? reply me plzzz....

author
capth00k made it!(author)2011-04-13

I would suggest building my other model (the little gem) mini guitar amp, as it sounds much better to my ear. Try using a 50K A (audio) PoT on your build.

Peace

Capt.

author
Thereyouhaveit made it!(author)2011-03-15

I completed building it , as a preamp , it sounds so soft when i put it into my power amp :(

author
Thereyouhaveit made it!(author)2011-03-15

as a guitar amp for a passive strat .

author
Thereyouhaveit made it!(author)2011-03-03

Hey , can i use this as a pre amp ?

author
theVader75 made it!(author)2011-03-02

can I use MC1458CP1 or OP270GP for this application?

author
coolguy2015 made it!(author)2011-02-06

my input is mono, how can i connect it??

author
Teburon made it!(author)2011-02-18

i'm wondering too. how did you solve this? just connect all the grounds together?

author
coolguy2015 made it!(author)2011-02-18

yes, i did connect all the grounds and the sleeve of the jack together.

author
coolguy2015 made it!(author)2011-02-08

Its working but when i turn the switch, there is no distortion except clean sound.. plzz any one help me......

author
Teburon made it!(author)2011-02-18

did u use 10uF capacitor for the dirty sound? if you only used Switch -> .01uF -> LM386 then you'll only get clean sound

author
coolguy2015 made it!(author)2011-02-18

I've used 10uF capacitor

author
coolguy2015 made it!(author)2011-01-19

dude i have a 6 volts DC adapter, can i use it instead of 9v??

author
brainstromer made it!(author)2010-12-29

hi there
i have some question
di ineed to use spesifik capasitor
like mylar or elco??
because on my country not all tipe capasitor avalaible
and i don't see "spesific type" on your diagram

sorry for my bad english
thanks bro..

author
warfighter made it!(author)2011-01-03

can u pls tell me if it is electrolitic (elco) or normal capacitor
thnx

author
capth00k made it!(author)2011-01-03

Normal Radial / Axial capacitors.

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author
capth00k made it!(author)2011-01-03

Just use Radials. Sometimes I use axials. The best 'tone' capacitors are Paper in Oil however. Find those, and you're golden.

author
dan95 made it!(author)2010-12-10

where do i plug the distortion dip switch

author
capth00k made it!(author)2010-12-11

Where the 2.2 uf - 10 uf capacitor is after the 'clean / distortion' switch. To do the 5 tone dip switch just bride one side of the switch as 'negative', and wire em up as shown off the dip switch. If you have more than one on, remember you will be adding (2.2uf + 1 uf = 3.2 uf, etc.) to make unique distortion tones.

Additionally, you can use a rotary switch to do the same thing without having to fuss with a dip switch (cheaper) ; a 12 position rotary switch is perfect for it.

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author
WALLz made it!(author)2010-11-09

Powersome! \o/

author
Falcore made it!(author)2010-04-12

It sounds AWESOME!!! I had a similar amplifier with LM386 but I decided to try this as a portable amp for my phone and it has great power and quality...

author
capth00k made it!(author)2010-09-19

Yep, just don't use pins 1 / 8 and there won't be any gain

peace,

K

About This Instructable

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Bio: I am a musician, internet developer, and a hobbyist pedal builder.
More by capth00k:Fixing an iMac g5 Power Supply using an ATX (pc) PSUThe ' Little Gem ' - Mini Amplifier / Guitar Amp -Portable Guitar Amp with distortion / Bass Amplifier - 9v / LM386 IC
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