This Vocoder module displays the control voltages up to 24 Vocoder Channels. The display is linear and displays the voltage from 0..5V with means of LM3914. Due to the modular build you can start with 8 Channels and add more (16, 24) as you need. The display is multiplexed and runs on 6V to minimize power consumption. It is not essential to run the Vocoder but it adds a nice feature. You can see the spectral distribution of your signal. This comes in handy from time to time.

Vocoder Display Front

Vocoder Display Inside

Vocoder Display Bargraph PCB

Schematics are found on my website