instruo-i-o47

Instruo I-ō47

Modern multimode resonator/filter inspired by the ARP 2500 1047

14 HP Eurorack module

I-ō47 is a multimode resonator/filter inspired by the classic ARP 2500 1047, featuring a hybrid design of matched transistor pairs and precision op-amps. It provides simultaneous low pass, high pass, band pass, and notch outputs at a steep -18dB/oct slope. With an on-board limiter/waveshaper, exponential FM, variable notch with CV, pingable resonance via Strike input, an inverting secondary input with dynamic amplitude tied to Q, and a feedback toggle for self-oscillation, I-ō47 is a versatile filter that doubles as a sine wave oscillator and percussion source.

Features

  • Simultaneous LP, HP, BP, and Notch filter outputs
  • -18dB/oct slope on LP and HP, -6 to -18dB/oct on BP
  • Self-oscillating resonance with feedback toggle
  • 1V/Oct tracking for pitch-accurate oscillator use
  • Strike input for pingable resonance and hard-sync effects
  • Variable notch with CV-controllable centre frequency offset
  • On-board tanh limiter/waveshaper on primary input
  • Inverting secondary input with Q-linked amplitude reduction
  • Exponential FM input with bipolar attenuverter
  • Hybrid semi-discrete VCA design with matched transistor pairs
  • Frequency range: 16Hz to 16kHz
  • Quadrature sine waveform oscillator when self-oscillating

Controls & Jacks (19)

  • Coarse
  • Fine
  • FM Attenuverter
  • Q
  • Notch
  • Input
  • Limiter
  • Gain
  • Inverting Input
  • 1V/Oct
  • Strike
  • Feedback
  • LP Output
  • FM
  • BP Output
  • Notch CV
  • HP Output
  • Q CV
  • Notch Output

How-To Guides

  • East Coast Synth Voice
  • Sine Wave Oscillator
  • Phaser Effect
  • Percussion: Kick Drum
  • Dynamic Input Crossfade

Explore the interactive I-ō47 panel on BleepDex — tap any control to learn what it does.

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