Instruo I-o47

MUSICAL FEATURES

 The I-ō47 is a multi-mode resonator filter inspired by the 1047 module of the ARP2500, with a modern twist. The internal VCA is designed with a combination of matched transistors and precision operational amplifiers. Outputs can be low-pass, band-pass, high-pass, and notch outputs simultaneously. The notch offset can be controlled with a small knob. The input has two main inputs with gain adjustment and an inverting input whose gain depends on the resonance.

 Cutoff and Q (resonance) can be CV controlled. 1V / Oct input is provided, and fine tuning of the frequency (Fine) is possible, so it is also possible to create a melody suitable for the scale by oscillation or pinging.

 The feedback switch emphasizes resonance by returning the bandpass output to the input, enabling self-oscillation. The limit switch passes the sound after gain adjustment through a tanh-type limiter circuit to color the sound mildly.