[Last Updated: January 31, 2024] Today, we’re peeling back the curtain on Passive RC Filters! With just one resistor and one capacitor you can easily build a basic passive filter. This circuit proves useful in designing certain aspects of guitar effects pedals and helps you figure out how to modifying existing ones. Introducing: Passive RC […]
Circuit 12 of 48: The Passive RC Filter Read More »
[Last Updated: January 20, 2024] Welcome back to another exciting installment of our blog series on guitar effects pedal circuit design! Today, we’re diving into a crucial yet often underestimated aspect of building guitar pedals – the power supply. Imagine the power supply as the heartbeat of your pedal, providing the lifeblood for each note
Circuit 11 of 48: The Linear Regulator Read More »
What is a Charge Pump? A charge pump is an integrated circuit (IC) that is used to convert from one voltage to another. As an example, let’s say you want to build a circuit that runs on +18Vdc, but you want to power it using a +9Vdc adapter. You can use a charge pump IC
Circuit 10 of 48: The Voltage Doubler Read More »
What is a Charge Pump Inverter? A charge pump is an integrated circuit (IC) that is used to convert from one voltage to another. As an example, let’s say you want to build a circuit that runs on +18Vdc, but you want to power it using a +9Vdc adapter. You can use a charge pump
Circuit 9 of 48: The Charge Pump Inverter Read More »
Most modern guitar pedals have one thing in common: an indicator LED. This LED allows you to know whether the effect is engaged or bypassed. In this article, we go over everything you need to know about the indicator LED circuit for guitar effects pedals. The Diode: A Review LED stands for Light Emitting Diode.
Circuit 8 of 48: The LED Circuit Read More »
Guitar pedal battery switching, DC power disconnect, and expression pedal wiring explained Introduction Switches: the most engaging electromechanical component! Available in all sorts of shapes, sizes, and configurations – switches give us the ability to interact with the electronic world. In this post, we’ll be covering a very particular type of switch technology that will
Circuit 5 of 48: The Switched Jack Read More »
Guitar pedal power supply circuits come with all sorts of concerns, including: We saw how to deal with reverse polarity in Circuit 5: The Diode Protectors. The other two concerns involve common sources of noise in guitar effects design, and they can be addressed with a proper power supply filter. [Last Updated: January 7, 2024]
Circuit 6 of 48: The Power Supply Filter Read More »
By: Dominic Sciarrino | Stompbox Electronics | Last Published: February 27th, 2026 Introduction Plug in the wrong polarity power supply – even briefly – and the results can be immediate and expensive. Electrolytic capacitors fail catastrophically. ICs and transistors conduct in the wrong direction. Reverse voltage can destroy a circuit in seconds. The fix can
Circuit 4 of 48: Diode Protection Read More »
By: Dominic Sciarrino | Stompbox Electronics | Last Updated: February 26th, 2026 Introduction You’ve plugged a 9V power supply into a guitar pedal. But the circuit inside isn’t running 9 volts everywhere. Different stages need different voltages to operate correctly. A transistor amplifier stage needs a specific bias point. An op-amp needs a reference to
Circuit 3 of 48: The Voltage Divider Read More »
By: Dominic Sciarrino | Stompbox Electronics | Last Updated: February 25th, 2026 Introduction If you’ve ever built a true bypass pedal, you’ve probably heard a loud thump or pop the moment you engage the switch. It’s one of the most common problems in DIY pedal design, and it has a specific, well-understood cause … and
Circuit 2 of 48: The De-Popper Read More »
