Eurorack Reference

Make Noise / make-noise/maths

Maths

Analog computer designed for musical purposes. Generates linear, logarithmic, or exponential triggered or continuous functions; integrates, amplifies, attenuates, and inverts signals; adds, subtracts, and ORs up to 4 signals; generates analog signals from digital information and vice versa. [4]

Specifications

HP
20
Depth
32 mm
+12V
60 mA
−12V
50 mA
+5V
—
Last verified
2026-05-02

Capabilities

  • Attenuverter attenuverter
    Four attenuverter knobs in center of module scale, attenuate, and invert signals. CH2 and CH3 can also generate DC offsets (+/-10V and +/-5V respectively) when no signal is patched. [4]
  • Clock Source clock-source
  • Envelope Generator envelope-generator
    Channels 1 and 4 generate voltage controlled Attack/Decay envelopes (0V to 10V) when triggered, or Attack/Sustain/Release envelopes via the Signal Input. Range from 25 minutes to 1kHz. [4]
  • LFO lfo
    Channels 1 and 4 self-oscillate (Cycle) to generate LFO waveforms from slow (25 minutes) to audio rate (1kHz). Shape set by Vari-Response. [4]
  • Signal Mixer / Combiner signal-mixer
    All four channel Variable Outputs are normalized to a SUM bus (addition/subtraction), Inverted SUM bus, and OR bus (analog maximum/logic OR). Attenuverters weight each channel's contribution. [4]
  • Slew Limiter / Portamento slew-limiter
    Signal Inputs on all channels are Direct Coupled, allowing Lag, Portamento, and Slew processing of incoming control voltages via Rise and Fall controls. [4]

Jacks (24)

Inputs (13)

NameSignalVoltageDescription
Channel 1 Both CV Input cv -8V to 8V Bi-polar exponential CV input affecting the entire function (both Rise and Fall). Positive signals decrease total time; negative signals increase total time. [4]
Channel 1 Cycle Input gate ≥2.5V On Gate HIGH, Cycles on. On Gate LOW, does not Cycle (unless Cycle button engaged). Requires minimum +2.5V for HIGH. [4]
Channel 1 Fall CV Input cv -8V to 8V Linear CV input for Fall parameter. Positive signals increase Fall time, negative signals decrease Fall time. [4]
Channel 1 Rise CV Input mixed — [4]
Channel 1 Signal Input mixed -10V to 10V Direct Coupled input to circuit. Use for Lag, Portamento, ASR envelopes. Also input to Sum/OR Bus. [4]
Channel 1 Trigger Input gate — Gate or Pulse triggers the circuit regardless of Signal Input activity, producing a 0V to 10V envelope function. Used for Envelope, Pulse Delay, Clock Division, LFO Reset (only during Falling portion). [4]
Channel 2 Signal Input mixed -10V to 10V Direct Coupled input normalized to a +10V reference for generation of voltage offsets. Generates +/-10V offset when nothing is patched. [4]
Channel 3 Signal Input mixed -10V to 10V Direct Coupled input normalized to a +5V reference for generation of voltage offsets. Generates +/-5V offset when nothing is patched. [4]
Channel 4 Both CV Input mixed -8V to 8V [4]
Channel 4 Cycle Input gate ≥2.5V [4]
Channel 4 Fall CV Input mixed -8V to 8V [4]
Channel 4 Signal Input mixed -10V to 10V [4]
Channel 4 Trigger Input gate — [4]

Outputs (11)

NameSignalVoltageDescription
Channel 1 Variable Output mixed -10V to 10V Signal processed by Channel 1 attenuverter. Normalized to SUM and OR busses; inserting a patch cable removes signal from both busses. [4]
Channel 2 Variable Output mixed -10V to 10V [4]
Channel 3 Variable Output mixed -10V to 10V [4]
Channel 4 Variable Output mixed -10V to 10V [4]
End Of Cycle Output (EOC) gate 0V to 10V Goes high at the end of the Fall portion of the function. Defaults to +10V (High) when no activity. Useful for clocking and pulse-shaped LFO. [4]
End Of Rise Output (EOR) gate 0V to 10V Goes high at the end of the Rise portion of the function. Defaults to 0V when inactive. Useful for clocking, pulse delay, clock division. [4]
Inverted SUM Output mixed -10V to 10V Inverted version of the SUM Output. Allows modulating backwards. [4]
OR Bus Output mixed 0V to 10V Analog Logic OR output — always outputs the highest voltage of all four channel variable outputs. Does not respond to negative voltages. Useful for maximum voltage selection and half-wave rectification. [4]
SUM Bus Output mixed -10V to 10V Sum of all four channel variable outputs as weighted by their attenuverter controls. Can add, invert, or subtract voltages. [4]
Unity Signal Output (CH1) mixed 0V to 8V Signal from the Channel 1 circuit, not affected by the Attenuverter. 0-8V when Cycling; otherwise follows amplitude of the input. Not normalized to SUM/OR bus. [4]
Unity Signal Output (CH4) mixed 0V to 8V [4]

Parameters (12)

NameTypeRangeMin FWBehavior
CH1 Attenuverter knob — — Scales, attenuates, and inverts the signal being processed or generated by CH1. Connected to CH1 Variable Output and Sum/OR Bus. [4]
CH2 Attenuverter knob — — Scales, attenuates, amplifies, and inverts CH2 signal. With no signal present, controls level of the +/-10V offset generated by CH2. [4]
CH3 Attenuverter knob — — Scales, attenuates, amplifies, and inverts CH3 signal. With no signal present, controls level of the +/-5V offset generated by CH3. [4]
CH4 Attenuverter knob — — Scales, attenuates, and inverts the signal being processed or generated by CH4. Connected to CH4 Variable Output and Sum/OR Bus. [4]
Cycle Button (CH1) button — — Causes the circuit to self-cycle, generating a repeating voltage function (LFO). Use for LFO, Clock, VCO. [4]
Cycle Button (CH4) button — — [4]
Fall (CH1) knob — — Sets time for voltage function to ramp down. CW rotation increases Fall Time. [4]
Fall (CH4) knob — — [4]
Rise (CH1) knob — — Sets time for voltage function to ramp up. When triggered, circuit starts at 0V and travels to 10V; Rise determines how long. Also sets how fast an external control voltage can increase. Range spans from audio rate (1kHz) to 25 minutes. [4]
Rise (CH4) knob — — [4]
Vari-Response (CH1) knob — — Continuously variable response curve from Logarithmic through Linear to Exponential to Hyper-Exponential. Tick mark indicates Linear setting. Affects Rise and Fall shape. [4]
Vari-Response (CH4) knob — — [4]

Firmware history (0 versions)

No firmware history recorded.

References (2)