Has Anyone Tried Building a DIY Guitar Pedal with the LM386 Amplifier Chip?

A

Aria James

New member
Hey everyone,
I’ve been experimenting with simple DIY audio circuits lately and started wondering how far you can go using the LM386 as the core of a small effects pedal. I recently found this project on The Engineering Projects that walks through building a simple LM386 audio amplifier in Proteus https://www.theengineeringprojects.com/2021/06/simplest-lm386-audio-amplifier-in-proteus.html, and it really sparked my curiosity. I’ve also seen similar builds discussed on the Arduino forums and a few DIYStompboxes and Instructables posts where people used LM386-based circuits for fuzz or overdrive pedals. Has anyone here tried making one themselves? How does it actually sound compared to preamp ICs or op-amp–based designs like TL072 or NE5532? Would love to hear your experience or any tips on improving tone clarity when using the LM386 in pedal circuits.
 
Lots of pedals use the 386 amp---Acapulco Gold springs to mind. In my recollection, it's not exactly known for its high-fidelity, but can be fun to use in a dirty sounding mini amp or drive circuit
 
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Moonn released a big muff variant based on that IC.

Dropbox

www.dropbox.com www.dropbox.com

It's a single op-amp IC, like the TL71, it wont work as TL72 substitute, which is a dual-op-amp.

I tried to use it in circuits like the Bass brutalist from GCI, instead of an OP07. TL71 felt better, but it depends on the circuit and on your tastes, i guess.
 
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A lot of the clipping in LM386 circuits actually occurs at the input. If you want clean, you'll have to attenuate the input signal significantly, even if you opt for the 20x gain option.
 
Here’s a couple more you could build on stripboard, or maybe a pcb from another company.

Krank Distortus Maximus

Lovepedal Purple Plexi
 
There's also the DEAD-EASY DIRT circuit...

Feral Feline

Post in thread '"Express Lane" Pedals'

When I made my previous list I couldn't find the following which I've stumbled across on my HD again:


Transistors and Beer's Dead Easy Dirt

LM386 > 2µ2 > opposed 1N914 to ground > Vol pot


And since the criteria doesn't include pots you can actually narrow the above down to

- IC
- Cap
- diode 1
- diode 2


I'll have to breadboard this and see how it sounds.

Would be a great Dead-Bug build, two:

Hot glue the IC and pot back to back, solder on the Cap to IC-pin5 and other leg to VOL-3;
Diodes soldered from VOL3 to IC-Pin4 (or 2)...

I think it'd be still wise to include some extra...
  • Wow


But it's ssssoo easy it's sleazy and needs a couple of additional bits'n'bobs — in Chuck We Trust!

Chuck D. Bones

Post in thread '"Express Lane" Pedals'

There should be a current limiting resistor between the LM386 and the diodes.

The input impedance of the LM386 is nominally 50K. Will really load down the guitar if it's 1st in the chain.
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Repeating a few others' suggestions with a few additions... here're my notes on the 386...
BEAVIS TUFNEL

DAM SONIC TITAN : FUZZ DOG SONIC TIGHT’UN

EQD ACAPULCO GOLD & DERIVATIVES
 (ex GLASSJAW)
Fuzz Dog Total SOnic Destruction AG+BMPT

PCBGuitarmania AG + Bax & Clean NOT RECOMMENDED​

FRANTONE PEACH FUZZ Moonn

GREER, Nick, SUCKER PUNCH

LOVEPEDAL Black Magic/Purple Plexi,

LovePedal Jubilee Build Suggestion
http://guitar-fx-layouts.42897.x6.nabble.com/Lovepedal-Jubilee-Build-Suggestion-td41798.html
To those who have built this & find it Flubby & Fuzz like, Change the Drive 2 cap to 4n7, same as 4.7nf (47nF on Layout) to Pin 3!
Cross reference Purple Plexi 800 & Black Magic both use 4n7 to Pin 3. — Cheers music6000

DeadEndFX PU II PCB EXPERIMENTALISTS ANONYMOUS PARALLEL UNIVERSE II LM386 Fuzz w buffer buster on the front

HARRYMATIC 386 & 555 stutter fuzz



ATOMIC DISTORTION from Distorque 386>MPF102 JFET

DISTMAX by Musikding
2N5088 > 386 with 3-band EQ
Probably a clone of one these others, frantone? NOPE! Sure I’ve seen it before though, BJT followed by 386… [Distortus Maximus by Krank (I HAVE TAOBAO's and CDB's version)]​

velvet_fu##_boost_sectionv1.1 fuzz verofied

FUZZROCIOUS : RAM THE MANPARTS vero

Protone Body Rot II : Perf
Krank Maximus, modified and “improved”: Protone Body Rot II (LM386)



ALSO
OZ COMPRESSOR
MARTYMART's TAKE ON THE OZ COMP (He wound up going with a Flatline comp in the end, BTW)
Click to expand...
 
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