ritual-electronics-miasma

Ritual Electronics Miasma

Voltage-controlled distortion with self-oscillating feedback loop and swappable rectification diodes

10 HP Eurorack module

Miasma is a 10HP voltage-controlled distortion with an open feedback loop and interchangeable rectification diodes. The signal hits a Gain stage (up to +20dB) feeding two clipping diodes mounted on a tool-free header, so you can swap diode types — 1N4148, 1N914, BAT42, 1N60, blue LED, plus your own — to reshape the distortion's character (symmetrical or asymmetrical). The OTA-based Feedback VCA mixes the post-distortion signal back into the input with no phase inversion, so even with no input patched the module self-oscillates. A Fdbk Out / Fdbk In normalled pair lets you insert filters, delays, or reverbs into the feedback path for tuned or surreal feedback patches. A Blend control crossfades dry/wet and a Level trimmer compensates for diode-dependent volume changes.

Features

  • Voltage-controlled distortion with up to +20 dB of pre-gain
  • OTA-based VCA on both Gain and Feedback for clean CV control
  • Open feedback loop — Fdbk Out / Fdbk In normalled pair
  • Self-oscillates with no input when feedback is high enough
  • Interchangeable rectification diodes (header-mounted, no tools needed)
  • Ships with six diode types: 1N4148, 1N914, BAT42, 1N60, blue LED, plus a spare
  • One diode per waveform polarity — supports symmetrical or asymmetrical clipping
  • Bipolar attenuverters on both Gain and Feedback CV inputs
  • Front-panel Level trimmer for diode-dependent make-up gain
  • Dry/wet Blend control for parallel distortion
  • 100k input impedance, 1k output impedance
  • Responds extremely well to audio-rate modulation on Gain and Feedback CV

Controls & Jacks (12)

  • Feedback— Sets the initial amount of distorted signal feeding back into the distortion circuit. Pushes Miasma into self-oscillation when raised — work
  • Gain— Sets the initial amount of gain applied to the input signal — up to +20dB. Higher gain means more distortion intensity but reduces audible f
  • Blend— Crossfades between the dry input signal (fully CCW) and the 100% wet distorted signal (fully CW). Use this for parallel distortion or precis
  • Gain CV Attenuverter— Bipolar attenuverter for Gain CV input. CW adds CV to the Gain knob position; CCW subtracts. At 12 o'clock no CV is applied. Allows positive
  • Fdbk CV Attenuverter— Bipolar attenuverter for Feedback CV input. CW adds CV to the Feedback knob position; CCW subtracts. At 12 o'clock no CV is applied.
  • Level— Front-panel trimmer that sets the output volume to compensate for level differences between rectification diode types. Does not affect the d
  • Gain CV In— CV input for the Gain parameter. Voltage is scaled by the Gain CV Attenuverter and summed with the Gain knob. Responds well to audio-rate mo
  • In— Audio input. 100k impedance. The input signal voltage greatly influences the distortion character — higher input levels produce more aggress
  • Fdbk CV In— CV input for the Feedback parameter. Accepts -5/+5V. Voltage is scaled by the Fdbk CV Attenuverter and summed with the Feedback knob. Excell
  • Fdbk In— Feedback loop input — receives the signal returning from the feedback path. Normalled to the Fdbk Out jack: when nothing is patched, Miasma
  • Out— Main audio output of the distorted/blended signal. 1k output impedance. Carries the Blend mix between dry input and the wet distortion stage
  • Fdbk Out— Feedback loop output — sends the post-distortion signal out for external processing. Normalled to Fdbk In, so unpatching simply closes the i

How-To Guides

  • Subtle warmth
  • Aggressive crunch
  • Modulated grit (audio-rate FM)
  • Self-oscillating chaos (no input)
  • Tuned feedback (filter in the loop)

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

8c571ce