These are the three main blocks of the circuit. Then, we must build each channel, and finally mix all the channels. First, we must have input amplifiers for each of the two inputs. This vocoder will analise the signal on 14 bands, but the design can easily be modified to include more channels, or actually fewer (if you are in a hurry).
The program signal is then fed to an analysis section, which extracts the spectral information from the sound and applies it to the carrier signal. The first input is the program (usually a connected to a microphone) and the second input receives a carrier signal (usually a keyboard). A vocoder basically has two inputs and one output. I focused on using easily obtainable components that are inexpensive, and I tried to keep the circuit as simple as possible without sacrificing functionality. I designed it from scratch, although I did investigate as many vocoder schematics I could get my hands on. The first thing we need is a circuit design, which I am posting as a series of images.
