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 »
[Last Updated: February 27th, 2026] The Attenuator When you use a volume control knob on your guitar effect pedal you are most likely using a circuit called an attenuator. An attenuator is a circuit that decreases the amplitude of a signal. Attenuators are usually built with components called potentiometers. The Potentiometer A potentiometer (or pot,
The Attenuator Circuit 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 »
The BOSS compact pedal series was introduced in 1977, and with it came the ACA adapter power supply. BOSS introduced it’s modern power adapter, the PSA adapter, and has since moved on from the unregulated ACA equivalent. As a result, guitarists purchasing these legacy BOSS pedals have found problems using the ACA-based pedals with the
Convert Your Boss ACA Pedal to PSA 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 »
By: Dominic Sciarrino | Stompbox Electronics | Last Updated: February 23, 2026 Introduction Every guitar effects pedal has to solve one problem before it does anything else: how to switch the signal on and off. That’s the bypass circuit. Most explanations treat bypass as a single thing, but that framing misses something important. There are
Circuit 1 of 48: The Bypass Read More »
The Electro Harmonix LPB-1 has been a staple on my board for quite some time. The circuit is easy to understand, lending itself as a key starting point for those interested in modifying guitar pedals. In this article, we go over two EHX LPB-1 mods that will make it a useful addition to your pedalboard.
2 Useful EHX LPB-1 Mods Read More »
Audio probing guitar effects circuits is an essential skill for the stompbox designer, repair person, and modder. An audio probe is a device used for detecting audio signals at specific points in a circuit. It is especially used to troubleshoot guitar effects circuits, and you can build one using just a few components. In this
The Definitive Guide to Audio Probes Read More »
Often times you will need to specify, purchase, and replace electrolytic capacitors when dealing with audio electronics. Whether you are building audio circuits, or repairing vintage equipment, this is a necessary skill you need in your toolbox. By the end of this article, you will know the most important factors you need to take into
Electrolytic Capacitor Replacement Guide for Audio Electronics Read More »
The BOSS DS-1 distortion has been with us for almost half a century. The DS-1 is a distortion pedal with a relatively simple circuit and has been popularized by the likes of Kurt Cobain, Joe Satriani, Robert Smith, Steve Vai, and others. Most iterations of the DS-1 have been built with through-hole electrical components, making
Top 9 BOSS DS-1 Modifications Read More »
