I-ō47 Multimode Resonator/Filter is a modern take on a vintage circuit design inspired by the classic 1047 module of the ARP2500. It has been designed with some extra features and quirks built in.
The internal VCA’s are a new hybrid design of matched transistors and precision op-amps.
With CV controllable centre frequency, resonance/Q and notch offset along side FM, strike and a complex dual input with wave shaping limiter, the I-ō47 is truly a filter for all occasions.
I-ō47 | ʌɪ-əʊ-ˈfɔːti-ˈsɛv(ə)n | noun (signal processing) the in’s and out’s of a classic multimode filter/resonator
- Centre frequency range 16Hz to 16KHz
- 1V/octave, Coarse and Fine frequency controls
- FM input with attenuverter
- Low pass 12 dB/octave
- High pass 12 dB/octave
- Band pass 6 – 12 dB/octave dependent on Q
- Notch with variable offset –/+ 2 octaves
- Input with gain control
- Inverted input with resonance dependent gain
- Strike input for pinging the filter
- Feedback switch which adds BP to the input for enhances resonance
- Limiter based on tanh wave shaper which affects primary input (post gain fader)
Sometimes searched for as io47, i-047, i-o47