Mutable Instruments Rings
Physical modelling resonator for bars, tubes, and strings
14 HP Eurorack module
Rings is a resonator module that transforms unpitched excitation signals into full-bodied pitched sounds using physical modelling techniques. It simulates vibrating structures such as bars, tubes, and strings through modal synthesis, sympathetic string resonance, and extended Karplus-Strong methods. With its polyphonic capability and three resonator types, it ranges from delicate plucked strings to inharmonic metallic bells and glassy tones.
Features
- Three resonator types: modal synthesis, sympathetic strings, and modulated/inharmonic Karplus-Strong
- Selectable polyphony: mono, duo, and quad with overlapping voice tails
- Odd and even complementary audio outputs for stereo-like separation of partials
- Internal excitation generator (pulse or noise burst) when IN is unpatched
- Automatic strum detection from V/OCT note changes or IN transients when STRUM is unpatched
- FREQUENCY CV input normalized to 1/12V for fine-tuning via attenuverter when unpatched
- Attenuverters on all five CV inputs
- V/Oct tracking with calibration procedure for accurate pitch tracking
- Firmware update via audio input
- Virtual notches on STRUCTURE knob at harmonically significant positions
- Polyphonic strumming for chord-like textures with single CV source
Controls & Jacks (24)
- Frequency CV — Additional CV input for frequency modulation with attenuverter control.
- Harmonic Structure CV — CV input for modulating the harmonic structure parameter with attenuverter control.
- Damping CV — CV input for modulating the damping parameter with attenuverter control.
- In — Audio excitation input. Receives the signal that excites the resonator. If unpatched, the module synthesizes an internal excitation signal (
- Brightness CV — CV input for modulating the brightness parameter with attenuverter control.
- Excitation Position CV — CV input for modulating the excitation position parameter with attenuverter control.
- Harmonic Structure — Controls the frequency ratio between partials: modal resonator structure (plate/bar/string), sympathetic string ratios (octaves/fifths), or
- Damping — Controls the decay time of the sound, from less than 100ms to about 10 seconds.
- Out — Main audio output of the resonator.
- V/Oct — Pitch control input. Expects 1V/octave control voltage. Module detects note changes to trigger strumming if no dedicated strum input is patc
- Aux — Auxiliary audio output providing an alternative or complementary signal.
- Strum — Trigger input to initiate strumming. Freezes current voice and starts a new note on the next voice in polyphonic mode. Normalized to step de
- Excitation Position — Controls the point on the string/surface where excitation is applied. Center position creates hollow sound by canceling even harmonics.
- Coarse Frequency — Coarse frequency control adjusted by semitone increments, spanning 5 octaves.
- Brightness — Adjusts the level of higher harmonics via low-pass filter on exciter and damping filter on modes. Low values simulate wood/nylon, high value
- Resonator Type Button — Selects between monophonic, duophonic (2-voice), and quadriphonic (4-voice) operation.
- Polyphony — Selects between modal, sympathetic string, and modulated/inharmonic string resonators.
- Damping Attenuverter — Attenuverter for the Damping CV input.
- Brightness Attenuverter — Attenuverter for the Brightness CV input.
- Excitation Position Attenuverter — Attenuverter for the Excitation Position CV input.
- Frequency Attenuverter — Attenuverter for the Frequency CV input, functioning as fine frequency control when no patch cable is inserted (normalized to 1/12V).
- Harmonic Structure Attenuverter — Attenuverter for the Harmonic Structure CV input.
- Polyphony Mode — Selects between monophonic, duophonic (2-voice), and quadriphonic (4-voice) operation.
- Resonator Type — Selects between modal, sympathetic string, and modulated/inharmonic string resonators.
How-To Guides
- Calibrate V/Oct Tracking
- Recalibrate Normalization Detector
- Update Firmware via Audio
- One-Cable Plucked String
- Inharmonic Bell and Metal Tones
- Sympathetic String Drone Coloration
- Hollow Square-Wave Resonator
- Strummed Polyphonic Chord Texture
- Contact Microphone Body Resonance
- Sitar and Tanpura String Buzz
- Noise-Excited Pitched Percussion
- Generative S&H Resonator
Explore the interactive Rings panel on BleepDex — tap any control to learn what it does.
