Overloaded first log

A project log for Wurlitzer Key Note Visualizer Replica

Miniature, portable build of Wurlitzer's elusive keyboard teaching tool.

Guy DupontGuy Dupont 03/17/2020 at 17:380 Comments

I've done a bad job logging, but it's never too late to start.

I'm breaking this project down into four components:

Here's where I'm at.


I've got nothing here, and I will likely regret not thinking about this harder now. Though the original design uses a metal enclosure, I would prefer to make something nice out of wood. I'm going for vintage church-hall-bingo-board vibes. I don't think I could get it to the level of polish I'm looking for with my current skill set.  I will reach out for help with this soon.

Face plate

The face plate is done, save for a coat or two of clear gloss. I'm very happy with how it turned out.

I ripped the graphics by pulling some photos from this old auction and using Potrace to vectorize the black bits.  I did some pre-processing in Gimp (removing background and toning down colors to assist Potrace) and some final SVG cleanup using Inkscape. They're still not perfect, but I kinda like them that way. Gives a vaguely "hand-drawn" impression.

I'll post more detailed assembly instructions when I'm finished, but at a high level, you're looking at a translucent white sheet of acrylic, stenciled and spray-painted orange, and then decorated with vinyl decals cut on a Cricut Maker.


Each key on keyboard and note on the staff will have an RGB LED mounted behind it. For each of the two sections, I will be laser-cutting a "chassis" out of clear acrylic with precisely-placed holes for each of the 5mm bulbs. I will be surrounding each bulb with a 3D printed barrel to prevent leakage. The barrels will also collectively act as a standoff between the faceplate and the chassis. By pressing the end of each barrel against the face plate, I will ensure that the light will shine through as a well-defined circle.  I have not yet figured out how I will attach the chassis to the face plate.  It may make more sense to attach it elsewhere in the enclosure. TBD.

Here are some photos of my chassis prototype.  I have only mounted one LED so far, and I used a thin piece of cardboard in place of the acrylic:

ESP-32 Driving Lone LED
ESP-32 Driving Lone LED
3D Printed Barrel
3D Printed Barrel

The LEDs are driven by an ESP-32, which is acting as a BLE-MIDI peripheral to maximize compatibility with keyboards/other musical devices. And that brings us to...


I'm using the Arduino core for the ESP-32.  I found some great libraries that have made my life much, much easier. The basic functionality of notes -> lights is already working well.  I will get the .ino file hosted soon.  Here are the libraries I am using:

I'll be starting to push source files to the linked github repo starting today!