MUSICAL FEATURESThe I-ō47 is a modern multi-mode resonator filter inspired by the ARP2500 1047 module. The internal VCA is designed by combining matched transistors and precision operational amplifiers. The output can take out the low pass, the band pass, the high pass, and the notch output simultaneously. The notch offset can be controlled with a small knob. There are two main inputs, a main input with gain adjustment and an inverting input whose gain depends on resonance.
Cutoff and Q (resonance) can be CV controlled. Since it is equipped with a 1V / Oct input and the frequency can be finely adjusted (Fine), it is also possible to create a melody that suits the scale by oscillating or pinging.
The feedback switch emphasizes resonance by returning the bandpass output to the input and enables self-oscillation. The limit switch passes the sound after gain adjustment through a tanh type limiter circuit, and colors the sound mildly.