Logic gates (AND, OR, comparators) in Eurorack combine trigger and gate signals to create conditional rhythmic patterns

Logic modules process binary (on/off) gate and trigger signals using Boolean logic. An AND gate outputs a high signal only when all inputs are high simultaneously — e.g. triggering a hi-hat only when both the kick and a rhythmic gate are active at the same time, producing a dependent rhythm. An OR gate outputs high when any input is high. A comparator outputs a gate when a CV signal crosses a set threshold — converting a continuous modulation into on/off events. These utilities are the ‘plumbing’ that enables sophisticated conditional rhythms and event structures without a complex sequencer.

Examples

Clock / 4 signal AND clock / 3 signal -> AND gate output: a gate fires only when both sub-clocks coincide, producing a polyrhythmic accent. Use the output as a VCA CV or envelope trigger.

Assessment

Explain what an AND gate outputs given two clock signals of different divisions. Design a patch where a comparator converts an LFO into a rhythmic trigger for a drum module.