Working first draft of a rough spectrum analyzer. The incoming audio is passed through 8 SV filters, and each filtered audio band is then passed through an envelope generator. The CV output of each envelope generator, through a series of switches, tells the first page what the overall level of the band is. The 8 columns of pixels on the first page each represent one of the 8 bands, and so a general sense of the overall frequency content of the audio is visualized. It’s fun to watch it respond to audio with highly variable frequency content, such as from a drum machine.
The frequency bands are centered around:
40hz
80hz
160hz
320hz
640hz
1280hz
2560hz
5120hz
The last page has a couple of adjustable settings:
Rise time of the envelope generators
Fall time of the envelope generators
Bias of the signal – turn this up to light up more lights at the same level of sound.