Custom Piano Tickles The Ivories

The core ethos of “hacking” is usually interpreted as modifying something for a use that it wasn’t originally built for. Plenty of builds are modifications or improvements on existing technology, but sometimes that just isn’t enough. Sometimes we have to go all the way down and build something completely from scratch, and [Balthasar]’s recent piano-like musical instrument fits squarely into this category.

This electronic keyboard is completely designed and built from scratch, including the structure of the instrument and the keys themselves. [Balthasar] made each one by hand out of wood and then built an action mechanism for them to register presses. While they don’t detect velocity or pressure, the instrument is capable of defining the waveform and envelope for any note, is able to play multiple notes per key, and is able to change individual octaves. This is thanks to a custom 6×12 matrix connected to a STM32 microcontroller. Part of the reason [Balthasar] chose this microcontroller is that it can do some of the calculations needed to produce music in a single clock cycle, which is an impressive and under-reported feature for the platform.

With everything built and wired together, the keyboard is shockingly versatile. With the custom matrix it is easy to switch individual octaves on the piano to any range programmable, making the 61-key piano capable of sounding like a full 88-key piano. Any sound can be programmed in as well, further increasing its versatility, which is all the more impressive for being built from the ground up. While this build focuses more on the electronics of a keyboard, we have seen other builds which replicate the physical action of a traditional acoustic piano as well.

6 thoughts on “Custom Piano Tickles The Ivories

  1. Over here in the US I haul a 7 meter long truck full of pianos and older organs to the dump twice a year or so. Even spinet organ keyboards of 44 notes have 2 to graft into one big one with contacts to go unless it’s a Baldwin. They had variable resistance under each key!

    The shaft idea is used by Lo Duca, makers of a large number of Italian sourced keys to worldwide manufacturers. The only drawback as I commented about the “xylophone” in a recent post is slop which will make noise verses the felt cloth bushed joints that move to be as quiet as can be. Impressive to cut out keys. I didn’t see how the little cut is made between the naturals and sharps at right angle to the long cuts. Wire saw?

    The same with the rest. Lots of work, good work. I’d be happy to get MIDI out of a good salvaged set of keys and leave the synth to ZynAddSubFX. From what I know it’s possible to run a headless version with preset files of ZynAddSubFX on a late model Raspberry Pi, probably even with a screen GUI.

    1. If you are considering rPi, check Zynthian project. It can run ZynAddSubFX and a lot of other plugins, including Pianoteq. They have kits for sale, but if you check forums you’ll find a lot of wild DIY builds around it, including ones with the keyboards

    2. This is one fine piece of work! Hearty congratulations! He almost inevitably ended up creating a versatile music synthesizer, totally polyphonic.

      The player–piano–roll display, enhanced by color, was a fine touch!

      Analog synth technology is apparently quite alive and well. He used ADSR enveloping, which Bob Moog made popular; fine idea. Exponential amplitudes would have been welcome.

      It’s truly tough — it hurts, a /lot/ — to read of mass disposal of pianos and other keyboard instruments. Even good pianos, maybe excellent ones, can be had for the asking, apparently. Moving a good acoustical piano is significantly costly. Mine eyes doth water with the tragedy of it all. (I had to accept, also, the mass scrapping of CRT TVs, alas.) I dearly hope that such as Bösendorfers and Steinway concert grands don’t get trashed. As well, please don’t trash a Hammond Novachord!!

      Making an electronic piano that a serious pianist would respect is one devil of a challenge. Probably the best is a huge bunch of audio samples recorded on a fine acoustic piano, but afaik, nobody has duplicated the subtle acoustic coupling among undamped notes.

      A century and decades earlier, radio was just developing, and TV was experimental. I was born in 1936, when Nazi Germany broadcast the Olympics on TV. Guessing, maybe there were roughly a dozen receivers, if even that.

      Point is, that learning to play piano was common, because making music made life lots richer, and encouraged socializing. Pianos are superbly expressive, although tone color is what you get, but nevertheless, good pianists can create oodles of effects.

      If you start with a hammered* dulcimer, add a keyboard and dampers, you have a piano, of sorts. *US (& Canadian?) term; simply “dulcimer”, elsewhere.

      Regarding key dimensions, not to be chauvinistic, the AGO (American Guild of Organists) has a spec., which is apparently excellent.

      Guess what: The present–day ubiquitous key layout is an historical mess. Apparently, about 2/3 of the effort required to become fluent is spent struggling with its idiosyncracies. Go back far enough, and you learn that (in modern terms), keyboards were diatonic: only the white keys.

      As music progressed, we needed sharps and flats, but they were added piecemeal over centuries (afaik) to come up with the cruel monstrosity* we have, today. *I exaggerate.

      For a few centuries, music has been written based on* every one of the 12 keys per octave, but the layout is a C major scale!
      *The tonic, key signature (for tonal music…)

      Some fine minds have come up with key layouts that make it much easier to play in any key. Try an European accordion, with button keys for the melody. Try concertinas, but maybe not bandoneons. Probably the simplest mod. Is to reverse black and white in the cluster of seven, including F natural and B natural. Perhaps I’m wrong, but a major scale in any key is played on all white, or all black.

      Surely, I’m not trying to set a record for length of reply, but have been involved with electronics and music for about 79 years, with almost passionate interest in both, although music interest is fading, alas.

      In my early teens, I was inspired for life by electronics, when I discovered the MIT Radiation Lab series. I had a firm conviction that eventually, musical sounds created electronically could be co–equal to those created acoustically, in expressiveness and satisfaction. The Hammond Novachord, a pre-WW II totally polyphonic keyboard instrument, was an underappreciated landmark. I didn’t learn about it until ~1964, though.
      FM synthesis, with both carrier and modulation within the audio band, was/is another remarkable development.

      One of the few greatest thrills of by life was my first hearing of “Switched–On Bach”. I can explain why W. Carlos called the first Moog modular synths “notoriously bitchy” to keep in tune. I have done a small amount of such, and the comment is apt. Bob came to his senses, probably soon after. As well, I introduced ARP’s first customer to that company.

      My apologies and appreciation to Hackaday, with some hope these thoughts can help.

      1. “The player–piano–roll display, enhanced by color, was a fine touch!”
        Just to make sure – the display with colorful falling notes is not part of the instrument.
        The display is connected to a computer using the program “Piano From Above” which displays the notes on screen and sends the commands to the instrument over the MIDI cable. So the instrument there is responsible for playing the received notes and not for displaying the colorful rectangles.

  2. “didn’t see how the little cut is made between the naturals and sharps at right angle to the long cuts. Wire saw?”
    Everything was cut with the same saw.
    A smaller rectangle has to be cut from the bigger rectangle.
    This consists of a parallel and a perpendicular cut.
    The parallel cut is done before the key is separated from the big piece. It reaches only to the corner.
    Later wen the key is separated I insert it into a a small vice horizontally, and make the perpendicular from above.
    Finally, a small circle blade on a mini drill to finish the corner.

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