About 12 years ago (yikes!), I came across a rather interesting concept: it’s possible to use CMOS inverters to step up input voltage much the same way as dedicated charge pump ICs work. I loved this idea because it would be cheaper (much cheaper) to play with higher supply voltages for pedal circuits while keeping with the standard single-supply +9V input voltages that have ruled the pedal world from the beginning. Read More
Back in 2012, I put together the simplest circuit I could think of, which was a couple caps, a resistor or two, some diodes, and an LM386 amplifier IC. I left out everything that was 100% necessary for a functional circuit, including polarity protection, pulldown resistor, and power filtering. Lots of people built that simple circuit, so I thought I would update it a bit to include a few basic improvements that I had omitted from the original. The design owes a lot to the Big Daddy from RunoffGroove.
This one is perfect for breadboarding and experimenting. Try different diode types for D2 / D3, add a gain control via a pot between pins 1 and 8, change up the input and output caps, throw a simple boost in front, etc.
Also works great for building on perf or vero/strip board.
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Just got these boards in today and have begun the first prototype build. It’s an optical tremolo with both the audio path and LFO made from a single CD4049 CMOS hex inverter. Despite having it all function in a single IC, there is no LFO ticking in the audio. Two of the inverters are the audio path (input and output amplifiers), and three more inverters are arranged as a low-frequency oscillator. And the last inverter is unused (I may do another iteration later that uses this last inverter to add a bit of grit/drive).
There are three controls: Speed (pot), Depth (pot), and Triangle/Square (switch). The switch controls the wave shape of the LFO. Be default, the LFO products a VERY square output. To try to smooth this out as much as possible, I added a very large capacitor as a rudimentary low-pass filter on the wave. The result is pretty close to a triangle wave shape. And the switch allows you to choose which wave shape you want to use (obviously). There is also an LED to indicate LFO speed, and it is lit even when the pedal is bypassed. The pedal will be available with either a standard 3PDT mechanical bypass switch or with a relay-driven soft-touch bypass switch (modest upcharge for the latter).
I hope to have a demo video posted soon, and after that I plan to sell these primarily through a local music shop (who will ship pretty much anywhere), but I will also sell direct if someone would prefer that.
Pic of the mostly populated board:
I’m pleased to announce the first of a few pedals that will be hand built by me in small batches and sold as cheaply as I can manage. There are cheap Chinese pedals galore these days, but I want to try and get as close to I can to slave-labor prices but made in the USA. Think of it as “shabby chic” or maybe “bespoke” rather than old-school “boutique.”
I always liked the original ROG Phozer’s base sound, but the LFO wasn’t really that useful at lower speeds. So I took the basic idea, which is the Tim Escobedo’s Idiot Wah + LFO, and kicked it up a notch. Instead of the Phozer’s input JFET buffer, I went with an op amp buffer, and since there’s an extra amp in the package, I also added an output buffer. The LFO is the Shoot The Moon tremolo. For the variable resistor element, just about any of the usual suspects will work: LED/LDR combo, vactrol, or even one of those optical ICs such as the H11F1. And that’s how the Wahscillator came to be. Read More
There are many Rat clone projects out there, but this one is mine. This is a part-for-part clone of the original Rat circuit. There are no extra pots or switches…just three knobs of ass-kicking tone in a small PCB form factor. It’s laid out for 1N4148 / 1N914 diodes, but you could use pretty much whatever you want to mimic the various Rat version. My suggestions:
Or rather, AutoDesk has announced that they will stop support for and allow online access to Eagle CAD after July 2026. Presumably, older versions of the Eagle CAD will still work on the machines they are installed on. Read More
There have been many an online (and offline) argument about the nature of the classic Univibe pedal. Is the Univibe a phaser? Is it a vibrato? Or is it something in between or something altogether different? Read More
I have spent countless hours pouring over the circuits and notes that used to be hosted on a strange little website called Folk Urban (used to folkurban.com but it’s gone now). These so-called “circuit snippets” from a guy named Tim Escobedo (RIP) has inspired so many DIY pedal hobbyists to build pedals, create new circuits, and learn about electronics. Tim’s impact on the DIY pedal scene cannot be overestimated. His amazing insights and creative ideas will be sorely missed. Read More
Everybody seems to lust after “analog” pedals of all types, with delay/echo being the most sought after. But what’s going on under the hood of analog delay? The core of any analog delay pedals is the BBD chip, which stands for “bucket brigade device”. Read More
