Younger readers may not recall the days when every mall had a music store — not the kind where tapes and LPs were sold, but the kind where you could buy instruments. These places inevitably had an employee belting out mall-music to all and sundry on an electric organ. And more often than not, the organist was playing a Hammond organ, with the distinct sound of these instruments generated by something similar to this tonewheel organ robot.
Tonewheels are toothed ferromagnetic wheels that are rotated near a pickup coil. This induces a current that can be amplified; alter the tooth profile or change the speed of rotation, and you’ve got control over the sounds produced. While a Hammond organ uses this technique to produce a wide range of sounds, [The Mixed Signal]’s effort is considerably more modest but nonetheless interesting. A stepper motor and a 1:8 ratio 3D-printed gearbox power a pair of shafts which each carry three different tonewheels. The tonewheels themselves are laser-cut from mild steel and range from what look like spur gears to wheels with but a few large lobes. This is a step up from the previous version of this instrument, which used tonewheels 3D-printed from magnetic filament.
Each tonewheel has its own pickup, wound using a coil winder that [TheMixed Signal] previously built. Each coil has a soft iron core, allowing for the addition of one or more neodymium bias magnets, which dramatically alters the tone. The video below shows the build and a demo; skip ahead to 16:10 or so if you just want to hear the instrument play. It’s — interesting. But it’s clearly a work in progress, and we’re eager to see where it goes. Continue reading “Tonewheels Warble In This Organ-Inspired Musical Instrument”
The one thing you might be surprised not to find in [Laurent]’s beautiful tonewheel organ build is any tonewheels at all.
Tonewheels were an early way to produce electronic organ sounds: by spinning a toothed wheel at different frequencies and transcending the signal one way or another it was possible to synthesize quite an array of sounds. We like to imagine that they’re all still there in [Laruent]’s organ, albeit very tiny, but the truth is that they’re being synthesized entirely on an STM32 micro controller.
The build itself is beautiful and extremely professional looking. We were unaware that it was possible to buy keybeds for a custom synthesizer, but a model from FATAR sits at the center of the show. There’s a MIDI encoder board and a Nucleo development board inside, tied together with a custom PCB. The UI is an momentary encoder wheel and a display from Mikroelektronika.
You can see and hear this beautiful instrument in the video after the break.
Continue reading “A STM32 Tonewheel Organ Without A Single Tonewheel”
What can you do with ferromagnetic PLA? [TheMixedSignal] used it to give new meaning to the term ‘musicians’ gear’. He’s made a proof of concept for a DIY tone generator, which is the same revolutionary system that made the Hammond organ sing.
Whereas the Hammond has one tonewheel per note, this project uses an Arduino to drive a stepper at varying speeds to produce different notes. Like we said, it’s a proof of concept. [TheMixedSignal] is proving that tonewheels can be printed, pickups can be wound at home, and together they will produce audible frequencies. The principle is otherwise the same — the protruding teeth of the gear induce changes in the magnetic field of the pickup.
[TheMixedSignal] fully intends to expand on this project by adding more tone wheels, trying different gear profiles, and replacing the stepper with a brushless motor. We can’t wait to hear him play “Karn Evil 9”. In the meantime, put on those cans and check out the demo/build video after the break.
We don’t have to tell you how great Hammond organs are for making music. But did you know they can also encode secret messages?
Continue reading “Rock ‘n Roll With 3D-Printed Tonewheels”
There’s nothing new, ever. It’s all been done. But that doesn’t mean you can’t invent something interesting. A case in point is the Motor Synth, a crowdfunding project from Gamechanger Audio. It’s what you get when you combine advanced quadcopter technology with the market for modular and semi-modular synthesizers.
The core feature of the Motor Synth is an octet of brushless motors tucked behind a plexiglass window. These (either through an electromagnetic pickup or something slightly more clever) produce a tone, giving the Motor Synth four-note polyphony with two voices per key. On top of these motors are reflective optical discs sensed with infrared detectors. These are mixed as harmonics to the fundamental frequency. The result? Well, they got an endorsement from [Jean-Michel Jarre] at Superbooth earlier this month (see video below). That’s pretty impressive. Continue reading “The Motor Synth Is What You Get When You Forget Hammond Organs Exist”