Make It With Matty

DIY LM386 Mini Amplifier If you’ve ever wanted a tiny amplifier for your guitar, a retro console, or just to boost the sound from your phone, the LM386 audio amplifier IC is a perfect choice. It’s cheap, easy to wire, and surprisingly powerful for its size. In this post we’ll build a simple amplifier, then add a few extras to make it more versatile. I've used my guitar pedal prototyping board just for ease of building with a guitar input. How the LM386 Works The LM386 is a low-voltage power amplifier IC. At its heart, it takes a small audio signal and boosts it enough to drive a speaker. Runs on 5–12 V DC (a 9 V battery works great). Drives an 8 Ω speaker at a comfortable volume. Default gain is 20×, but you can boost it to 200× with a capacitor between pins 1 and 8. Parts You’ll Need 1 × LM386 IC 1 × 10 µF capacitor (for optional gain boost, non-polarized if possible) 1 × 220 µF electrolytic capacitor (output coupling) 1 × 100 nF capacitor (power deco...

Resistor Voltage Divider – A Simple but Essential Circuit If there’s one circuit you’ll keep coming across in electronics, it’s the resistor voltage divider . Simple, reliable, and everywhere, from measuring voltages to dimming LEDs, it’s one of the first building blocks worth learning. What is a Voltage Divider? A voltage divider is just two resistors connected in series across a voltage source. By tapping the middle point between them, you “divide” the voltage into a smaller, useful value. Formula: V o u t = V i n × R 2 R 1 + R 2 V_{out} = V_{in} \times \frac{R2}{R1 + R2} Where: V i n V_{in}  = supply voltage R 1 = resistor connected to input R 2 R2  = resistor connected to ground V o u t V_{out}  = output voltage between R1 and R2 Demo 1: Measuring a Higher Voltage Say you want to measure a 9V battery with an Arduino (which only tolerates up to 5V). Choose R 1 = 10 k Ω R1 = 10kΩ , R 2 = 10 k Ω R2 = 10kΩ Output will be: V o u t = 9 V ×...

Diodes: From Theory to Hands-On Practice In this post, we’ll introduce diodes, explain their basic theory, and walk through practical exercises that you can do with just a calculator, a breadboard, and a few simple components. What is a Diode? A diode is a two-terminal semiconductor device that allows current to flow in one direction only . Its symbol looks like an arrow pointing towards a bar: The left hand side with the white bar is the Cathode, the right hand side without the white bar is the Anode Forward bias : When the anode is more positive than the cathode, the diode conducts (after reaching a certain threshold voltage, usually ~0.7V for silicon). Reverse bias : When the cathode is more positive, the diode blocks current (almost no conduction until breakdown). This directional property makes diodes essential in rectifiers, protection circuits, voltage clamps, and logic circuits . Key Theory: Ideal vs. Real Diode Ideal diode : Conducts perfectly in one direction, b...

Simple 555 Timer astable oscillator This guide shows you exactly how to wire a 555 timer in astable mode and output to a led . Follow it carefully, and your circuit should work on the first try. Parts List R1 = 10 kΩ R2 = 100 kΩ R3 = 220 Ω (LED resistor) C1 = 10 µF electrolytic (timing capacitor) C2 = 10 nF (0.01 µF) (control pin noise bypass) C3 = 100 nF (0.1 µF) electrolytic (power supply decoupling — critical!) 1× LED 1× NE555 (or LM555) Supply = 5 V (clean supply preferred for first tests) Pinout Reference Hold the chip with the notch or dot facing up . Pins count counter-clockwise: Pin 1 = GND Pin 2 = TRIG Pin 3 = OUT Pin 4 = RESET Pin 5 = CTRL Pin 6 = THRESH Pin 7 = DISCH Pin 8 = VCC Circuit Diagram Wiring Instructions 1. Power & Housekeeping Pin 1 → GND Pin 8 → +5 V Pin 4 (RESET) → +5 V C3 (100 nF): across Pin 8 ↔ Pin 1 (place close to chip) C2 (10 nF): Pin 5 → GND 2. Timing Network R1 ...

Simple Boost guitar pedal. Using the guitar pedal prototyping board in previous post, I'm going to make a simple Boost guitar pedal. It is a great first build for guitar pedals. We are going to use a tl072cp  op-amp to create this b oost I’ll give you the parts/values and circuit diagrams for this simple boost pedal. Parts IC: TL072CP Diode: 1× 1N5817 (reverse protection) Resistors: 100 k (×2), 1 M (×1), 10 k (×1), 100–220 Ω (×1), 2.2 k (LED) Pots: B100k GAIN , B100k VOLUME Caps: 100 nF (×2), 10 µF (×2), 4.7–10 µF (×1), 10–33 pF (×1, ceramic/NPO) Hardware:  Previous guitar prototype board that we built. (Electrolytics: “+” toward the TL072/output side as noted below.) Circuit Diagram Wiring (non-inverting TL072 boost) 1) Power & decoupling +9V_RAW → 1N5817 → +9V (diode anode to +9V_RAW, cathode to +9V ) Pin 8 → +9V , Pin 4 → GND 100 µF from +9V to GND 100 nF directly between Pin 8 ↔ Pin 4 (close to IC) 2) Virtual ground (VREF, ...

Introduction Want to make two LEDs blink alternately without any ICs? In this project, we’ll build a simple two-transistor oscillator, also called an astable multivibrator,  using only NPN transistors, resistors, and capacitors from your parts collection. This circuit is a fun way to see: How capacitors can be used for timing. How transistors can act as switches in a feedback loop. How changing just one or two components can speed up or slow down the blink. How It Works The circuit has two identical halves that “hand off” control. When Q1 is on , its LED conducts current while its coupling capacitor pushes Q2’s base negative, keeping Q2 off. As the capacitor recharges through a resistor, its voltage rises until Q2 turns on and Q1 switches off. The cycle repeats in the opposite direction: Q2’s LED lights while Q1 is held off. This constant back-and-forth produces the alternating blink. For symmetric resistor and capacitor values, the oscillation period is ap...