studied the filters.
non recursive finite impulse response filter.
infinite impulse response filter:
want to build a filter that makes sound pass through physical material. first, needed to find a way to amplify audio signals, using o-amps.
made this while messing around with an op-amp.
understood how they work, and revised my understanding of efi_class-5.
watched serge tcherpnin, on waveshaper.
soldered my initial circuit.