Category Archives: Schematics

Schematics for various circuits.

The Downgrade – Analog Sampling Rate Reducer

BitRate Reducer The Squarewave Parade

It is hard to believe that half of a 40106 Hex Schmitt Trigger and single AD781 Sample and Hold amplifier IC can produce such a tasty lo-fi sounding effect processor. The circuit, which was developed and published by Tom Bugs on the BugBrand website is nothing short of genius with its utilization of the AD781 to sample, hold, and release a sound wave partial with each clock cycle of the 40106 oscillator. The result of such process is a very good simulation of what it sounds like to reduce the sampling rate from of a source from 44,100 Hz CD quality to 28,000 Hz NES or even lower 8,000 Hz Telephone Quality all in real-time. Impressed by the initial results and after weeks spent on research and development Steven of the Squarewave Parade asked Tom Bugs for a permission to modify the design and produce a limited run of 10 units, which are available for sale now. Each unit has been manufactured to be highly esthetically pleasing despite ultra decimating sounds under the hood. Currently each purchase also comes with a free original design T-Shirt. Nice work Steven!

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The downgrade the squarewave paradeBug Crusher Design

The downgrade

Atari Punk Console schematics

atari punk console beep schematic 556suchaturnon atari punk consoleatari punk console schematic

The so called “Atari Punk Console” device is a great start for builders interested in working with components and circuitry to produce Bleepy-Bloopy-Gitchy goodness. Using a 556 dual timer IC and a handful of other components one can be built quickly. The basis for this noise maker was a schematic originally published by Forest Mims III, which now can be found around the web and posted above for easy reference. The APC can be built into any case of your desire, and in the case of The SquareWave Parade even a vintage Atari joystick. The circuit is not only easy to build, but it is also easy to modify. The 556 IC is very resilient and cheap so don’t be afraid connect various pins to each other in order to discover new sounds. Touch contacts can be added in conjunction or as a substitute for the potentiometers and different values of capacitors can be swapped in to change the tone color dramatically and provide greater expression. Lots of links are available on this great little circuit:

Atari Punk Console is now available as a Kit from GetLoFi for only $24.

Worth Ekik

Kaustic Machines

MatrixSynth: Entry

Huge Huge Huge DIY Guitar Pedal Gallery

micro synthfuzz distortion diyvero board template

While browsing around the DIYguitarist forums looking for more info on a particular PT2399 Delay IC, I came across this link to a HUGE DIY Stompboxes gallery with schematics and build pictures. One can spend days leaching all the good distortion and classic effect schematics from this place. Make sure to save your favorites locally cause its not uncommon for this info to disappear after a while. Huge thanks to Aron Nelson for hosting this gallery. Enjoy.

Streetmachine Alligatron

circuit bent SK-1 case redcasio SK-1 circuit bentcircuit bent sk-1 with lamp

This lounge style Streetmachine Alligatron circuit Bent SK-1 comes via Joerg who runs a Casiobend forum, which dispite being located in Germany is actually all written in English. Joerg is also nice enough to post many shots that were taken in the process of building this device along with advice and even a schematic of the bends, which I believe was taken from the R.Q. Ghazala book. Very nice build expecially for the first project, keep up the good work.

Gieskes’ Video Bent Sega Mega Drive II

circuit bent sega mega driveschematic for circuit bending a sega mega drivecircuit bent sega mega drive

While browsing for something new to post I came across a new mod on the Gieskes.NL website. This time we have a circuit bent Sega Master System II with an RCA patchbay. Gijs was also nice enough to post a schematic refering to the IC which the patchbay was wired to. There are stills as well as some really neat videos on the site. It looks like certain patches only distort the scenes and not the actual characters or gameplay. Great for lofi visuals!

Ghetto Drum System

Ghetto Drum CaseGhetto Drum Pic circuitGhetto Drum Pic Controller

This acoustic piezzo trigger to serial interface is indeed pretty ghetto, but never to less there is plenty of great information on about programming a Pic Microcontroller for building such a device.The creator decided to use strait serial protocol for triggering samples through a custom application running on a PC and not through standard MIDI. Also housing projects in an external drive case does have advantages. Its cheap, rugged, and has a nice power supply built-in, so the circuit does not have to rely on battery power. The cases can always be painted if needed.

Barbie Karaoke Machine Circuit Bending


Pete of recently updated his website to include a blog. The very latest entry is a nice virtually step by step guide to circuit bending a Barbie Karaoke tape machine with echo effect. These rather pink devices are readily available on eBay for cheap. The resulting sounds are devastating to say the least. The tape motor control mod is also posted and I am sure can be applied to any tape device. The key appears to be the use of a voltage regulator, which outputs a steady voltage without effecting the rest of circuitry too much.

Circuit Bent Arion Guitar Effects

Bending cheap guitar effects pedals is a great way to start. More specifically these Arion pedals which can be purchased from Musicians friend and other online retailers for around $30. I would advise against Distortion pedals because those are too simple and contain no oscillator circuitry to play with. However chorus, octave, and delays are great. Most are built around the Bucket Brigade Delay ICs. Before deciding whether a particular pedal is worth bending check out the archives of schematics located on the super handy Experimentalists Anonymous website. There is just about every pedal schematic on there. also contains specific points of interest as well as some inside shots. Big thanks to Chris for sending in the inside wiring for the Bass Chorus and the Octave. Both of which contain enough points to require external break out boxes, massive rocker switches and joysticks.