Meet the Array from Bad Dog Designs: an audio spectrum analyzer with 18 channels that uses IN-13 Nixie tubes for visualization. Simply connect the device to your audio source to see it visualized. The Array doesn’t rely on digital electronics at all. Its rear panel lets you adjust sensitivity, access line in/out, and turn the device on/off.
The Array measures 14″ wide, 8″ tall and 6″ deep. You can find it on Etsy.