Behringer Abacus Analog Music Computer Eurorack Module

Behringer Abacus is an analog music computer module designed for Eurorack modular synthesizer systems. It enables control voltage processing and function generation for modular users, supporting modulation and timing workflows. This makes it ideal for Eurorack setups where multi-signal processing and function shaping are critical.

The module performs linear, logarithmic, and exponential triggered or continuous functions using control voltages. It supports combining multiple CV signals and generating envelope or LFO signals as part of a patchable control system.

In a modular system, it can be used to shape modulation movement, apply lag or slew to control voltages, and create timing-related events. Its input and output structure supports routing control signals to oscillators, filters, VCAs, and other modulation destinations.

Key Features

• Analog Music Computer: Algebraic sound processor modeled after Buchla's models 257 and 281 from the '60s
• Function Processing: Perform wide range of linear, logarithmic and exponential triggered or continuous functions
• Envelope and LFO Generation: Generate musical envelopes or LFO signals up to 25 minutes and as fast as 1 kHz
• Modulation Direction Control: Change the depth of modulation or even modulate backwards
• Control Voltage Processing: Amplify, attenuate, integrate or invert incoming signals for unlimited creativity
• Lag and Slew Processing: Apply lag, slew or portamento to control voltages for unique warped effects
• Multi CV Combination: Generate complex modulations by combining up to 4 CVs
• Output Activity Indication: LEDs indicate activity on all outputs for visual monitoring

Technical Specifications

Inputs
CV 1-4, Trig 1-4, Rise 1 & 4, Fall 1 & 4
Both 1 & 4, Cycle 1 & 4: 3.5 mm jack

Outputs
CV 1-4, OR, SUM, INV, ƒ1 & 4, 1 EOR, 4 EOC
3.5 mm jack

Controls
1 & 4 Rise, 1 & 4 Fall, 1 & 4 Response knobs
1 - 4 attenuverter knobs
1 & 4 Cycle buttons

Impedances
Rise & Both CVs: 100 kΩ
Fall CVs: 33 kΩ
CV Inputs 1 & 4: 33 kΩ
CV Inputs 2 & 3: 75 kΩ
Trigger Inputs: 100 kΩ
Cycle Trigger Inputs: 50 kΩ
Outputs 1-4, INV, SUM, OR: 680 Ω
EOR/EOC: 2.2 kΩ
ƒ 1 & 4: 100 Ω

Sensitivities
Trigger 1 & 4: 4 V minimum
Cycle 1 & 4: 1.8 V minimum

Power
Power supply: Eurorack
Current draw: 60 mA (+12 V), 50 mA (-12 V)

Dimensions
10 cm x 12.8 cm x 2.4 cm
(3.94" x 5.04" x 0.94")

Weight
191 g (6.74 oz)

Packaged Weight
284 g (10.02 oz)