At the heart of the vocoder: the channel filter board
The analysis/synthesis channel board is based on a standard 8-pole multi-feedback bandpass filter topology. For accuracy and temperature stability, resistors from the E48 series and SMD capacitors (size 1206 or 0805) with C0G/NP0 dielectric are used. A total of 18 boards cover a frequency range from 120 Hz to 7 kHz.
For a detailed view, click on the image.