ADSL Router As Effects Pedal

Moore’s law might not be as immutable as we once though thought it was, as chip makers struggle to fit more and more transistors on a given area of silicon. But over the past few decades it’s been surprisingly consistent, with a lot of knock-on effects. As computers get faster, everything else related to them gets faster as well, and the junk drawer tends to fill quickly with various computer peripherals and parts that might be working fine, but just can’t keep up the pace. [Bonsembiante] had an old ADSL router that was well obsolete as a result of these changing times, but instead of tossing it, he turned it into a guitar effects pedal.

The principle behind this build is that the router is essentially a Linux machine, complete with ALSA support. Of course this means flashing a custom firmware which is not the most straightforward task, but once the sound support was added to the device, it was able to interface with a USB sound card. An additional C++ program was created which handles the actual audio received from the guitar and sound card. For this demo, [Bonsembiante] programmed a ring buffer and feeds it back into the output to achieve an echo effect, but presumably any effect or a number of effects could be programmed.

For anyone looking for the source code for the signal processing that the router is now performing, it is listed on a separate GitHub page. If you don’t have this specific model of router laying around in your parts bin, though, there are much more readily-available Linux machines that can get this job done instead.

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Processing Audio With The RP2040

The Raspberry Pi, although first intended as an inexpensive single-board computer for use in education, is now ubiquitous in electronics communities. Its low price as well as Linux platform and accessible GPIO make it useful in many places outside the classroom. But, if you want to abandon the ease-of-use in favor of an even lower price, the Raspberry Pi foundation makes that possible as well with the RP2040 chip, commonly found on the Pico. [Jason] shows us one way to make use of this powerful chip by putting one in an audio digital signal processing board.

While development boards are available for this chip, [Jason] has opted instead for a custom PCB which he designed himself and includes an integrated headphone amplifier and 3.5 mm audio jacks. To do the actual DSP work, the RP2040 chip uses three 12-bit ADC channels and 16 controllable PWM channels. The platform is also equipped with the TLV320AIC3254 codec from Texas Instruments. With all of this put together, he has a functioning open-source platform he calls the DS-Pi.

[Jason] has built this as a platform for guitar effects and as a customizable guitar amp modeler, but with a platform that is Arduino-compatible and fairly easy to program it could be put to use for anything involving other types of music or audio processing, like this specialized MIDI-compatible guitar effects platform which is built around the same processor.

Bass Guitar Gets Shapeshifting Pickups

Electric guitars were the hip new thing back in the mid-century. The electrification of the common and portable guitar opened up a lot of avenues in terms of sound and technique. Specifically, the use of the pickup, an electromagnetic device which converts the vibrations of the guitar strings into electrical signals, increased the number of ways that a musician can alter the guitar’s sound on-the-fly. Some guitars have several rows of pickups which can be used in any number of ways, but this custom guitar has a single pickup which can be moved around the guitar’s body instead.

[Breno] was gifted this Dolphin bass guitar to start learning after years of playing a regular guitar, and while they aren’t known for high-quality instruments this guitar seemed to play and sound well enough to attempt this modification. First, a hole had to be cut all the way through the guitar’s body in order to accommodate the build. The pickup for this guitar is then mounted on two rods which allow it to move in various positions along the strings, and a second set of adjustments can be made to bring the pickups closer or further away from the strings. Some additional custom circuitry was added to control it and also to handle the volume and tone knobs, and while this was being added [Breno] and his friend [Arthur] decided this would be a great time to build some effects into the guitar’s now-custom electronics as well.

While this was largely a project for [Breno] to understand in greater depth the effect of moving the pickups around an electric guitar, the finished product looks ready to play some live shows. The addition of some extras like the effects really adds some punch to this guitar and it looks to be completely original. The nearest thing we could find is this guitar which uses hot-swappable pickups but even those are mounted in fixed locations.

A musical cyberdeck

Musical Cyberdeck Is Part Synth, Part MIDI Controller, And All Cool

When a new project type starts to get a lot of exposure, it’s typically not long before we see people forking the basic concept and striking out in a new direction. It happened with POV displays, it happened with Nixie clocks, and now, it seems to be happening with cyberdecks. And that’s something we can get behind, especially with cyberdecks built to suit a specialized task, like this musical cyberdeck/synth.

Like many musicians, [Benjamin Caccia] felt like he needed a tool to help while performing with his band “Big Time Kill.” He mainly needed to trigger track playbacks on the fly, but also wanted something to act as a mega-effects pedal and standalone synth. And while most of that could be done with an iPad, it wouldn’t look as cool as a cyberdeck. The build centers around a Raspberry Pi 4 and a 7″ LCD display. Those sit on top of a 25-key USB MIDI keyboard and a small mixer. Alongside the keyboard is a USB keypad, which has custom mappings to allow fast access to buried menu functions in the cyberdeck’s Patchbox OS. Everythign was tied together on a 3D-printed frame; the video below shows it in action, and that it sounds as good as it looks.

We think [Benjamin]’s cyberdeck came out great. Need to see some other specialized cyberdecks? Why not take a look at this battle-ready cyberdeck, one that aims to be distraction-free, or a cyberdeck for patrolling the radioactive wastelands.

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Neural Networks Emulate Any Guitar Pedal For $120

It’s a well-established fact that a guitarist’s acumen can be accurately gauged by the size of their pedal board- the more stompboxes, the better the player. Why have one box that can do everything when you can have many that do just a few things?

Jokes aside, the idea of replacing an entire pedal collection with a single box is nothing new. Your standard, old-school stompbox is an analog affair, using a combination of filters and amplifiers to achieve a certain sound. Some modern multi-effects processors use software models of older pedals to replicate their sound. These digital pedals have been around since the 90s, but none have been quite like the NeuralPi project. Just released by [GuitarML], the NeuralPi takes about $120 of hardware (including — you guessed it — a Raspberry Pi) and transforms it into the perfect pedal.

The key here, of course, is neural networks. The LSTM at the core of NeuralPi can be trained on any pedal you’ve got laying around to accurately reproduce its sound, and it can even do so with incredibly low latency thanks to Elk Audio OS (which even powers Matt Bellamy’s synth guitar, as used in Muse‘s Simulation Theory World Tour). The result of a trained model is a VST3 plugin, a popular format for describing audio effects.

This isn’t the first time we’ve seen some seriously cool stuff from [GuitarML], and it also hearkens back a bit to some sweet pedal simulation in LTSpice we saw last year. We can’t wait to see this project continue to develop — over time, it would be awesome to see a slick UI, or maybe somebody will design a cool enclosure with some knobs and an honest-to-god pedal for user input!

Thanks to [Mish] for the tip!

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Circle Guitar Creates Wall Of Sound

In the 60s a musical recording technique called the “wall of sound” came to prominence which allowed artists to create complex layers of music resulting in a novel, rich orchestral feeling. While this technique resulted in some landmark albums (Pet Sounds by the Beach Boys for example) it took entire recording studios and many musicians to produce. This guitar, on the other hand, needs only a single musician but can create impressive walls of sound on its own thanks to some clever engineering.

Called the Circle Guitar and created by [Anthony Dickens], the novel instrument features a constantly-rotating wheel around the guitar’s pickups in the body. Various picks can be attached in different ways to the wheel which pluck the strings from behind continuously. This exceeds what a normal guitar player would be able to do on their own, but the guitarist is able to control the sounds by using several switches and pushbuttons which control a hexaphonic humbucker and are able to mute individual strings at will. Of course, this being the 21st century, it also makes extensive use of MIDI and [Anthony] even mentions the use of a Teensy.

While details on this project are admittedly a little fleeting, the videos linked below are well worth a watch for the interesting sounds this guitar is able to produce. Perhaps paired with a classic-sounding guitar amplifier it could produce other impressive walls of sound as well. Either way, we could expect someone like [Brian Wilson] to be interested in one once it is in production.

Thanks to [Mel] for the tip!

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MIDI Guitar Pedals

Ever since Jimi Hendrix brought guitar distortion to the forefront of rock and roll, pedals to control the distortion have been a standard piece of equipment for almost every guitarist. Now, there are individual analog pedals for each effect or even digital pedals that have banks of effects programmed in. Distortion is just one of many effects, and if you’ve built your own set of pedals for each of these, you might end up with something like [Brian]: a modular guitar pedal rack.

ae0fmjxTaking inspiration from modular synthesizers, [Brian] built a rack out of wood to house the pedal modules. The rack uses 16U rack rails as a standard, with 3U Eurorack brackets. It looks like there’s space for 16 custom-built effects pedals to fit into the rack, and [Brian] can switch them out at will with a foot switch. Everything is tied together with MIDI and is programmed in Helix. The end result looks very polished, and helped [Brian] eliminate his rat’s nest of cables that was lying around before he built his effects rack.

MIDI is an extremely useful protocol for musicians and, despite being around since the ’80s, doesn’t show any signs of slowing down. If you want to get into it yourself, there are all kinds of ways that you can explore the studio space, even if you play an instrument that doesn’t typically use MIDI.