IDUM by Mystic Circuits is a special combination of clock modulator and random generator specialized for IDM (Intelligent Dance Music). Since IDM in itself is quite a complex genre of electronic music because of the fast gates, tremolos and hack effects, Mystic Circuits has thought about how to keep the musical expression in simple control processes in a manageable effort for Eurorack modular systems.
The module's four trigger outputs are used to open VCAs, trigger envelopes, drum modules or reset functions of other modules. IDUM itself does not process audio signals. The trigger inputs wait for incoming gates to affect the currently selected algorithm. To control when IDUM's effects are active, the CHANCE control sets the probability that an effect will be activated at a given step, and the LENGTH control determines how many steps the effect lasts for. The PARAM knob controls a parameter specific to each effect, while the MODE knob selects the mode. All of these controls, as well as the LOOP state, have their own CV modulation inputs. Additive to the following eight modes controlling the trigger outputs, the module has an eight-step looper that loops incoming Gates as well as any effects active on those steps.
IDUM's eight modes:
HOLD - Changes the length of incoming triggers.
BURST - Creates a ratcheting effect whose timing is determined by the Clock.
MULTIPLY/DIVIDE - Creates a ratcheting effect whose timing is determined by the incoming triggers.
BALL - Creates a "bouncing ball" effect.
ROTATE - swaps the connections of inputs and outputs.
DELAY - delays incoming Gates and a dynamic period of time depending on incoming triggers.
BREAK - preset rhythms that turn incoming triggers into breakbeats.
SKIP - manipulates the clock output to multiply the clock speed or jump forward several steps.