Use a Series of IN-13 Nixie Tubes to Create an Audio Visualizer

Nixie tubes have been around since the ’50s and were primarily used in military equipment for displaying numbers and letters. As technology advanced, these devices fell to the wayside and were picked back up again several decades later by engineers and makers to incorporate into a myriad of different projects, with the most notable being clocks. Another great use for the neon tubes is audio visualizers, which is what engineer Will Yager created with his Nixie Tube Audio Meter.

Yager designed his audio visualizer with 16 IN-13 Nixie tubes that are secured to custom modular daisy-chainable boards, which power and control four tubes per PCB. Driving the audio meter is a Microchip SAM D11 microcontroller with all pins used — four PWM, two bidirectional UART, with programming interface exposed via SWD header, and a single power control output. Yager states the high-voltage can be turned off/on with a TPS2281 PMIC, while an NCH8200HV module is used to generate 170V to power the tubes.

Each Nixie tube in the audio visualizer can be calibrated via a trimpot, while a control board processes the audio to determine what levels are shown on each tube. The control board also detects how many tubes are connected and automatically displays the correct number of bands. He states his audio meter can read audio signals through either Toslink (optical) or S/PDIF connections, which leaves out HDMI or USB-C options, although that’s not necessarily a deal-breaker. Yager has provided a detailed walkthrough of his Nixie Tube Audio Meter on his blog — complete with links to schematics, files, and code for those looking to recreate his build.