The Behringer Abacus is a eurorack module that is based on the Don Buchla-designed 257 and 281 analogue synths. Or is it? Whichever way way you like at it, it is designed to Make Noise.

It generates LFOs 25 minutes in length and as fast as 1 kHz.
Incoming signals can be an amplified, attenuated, integrated or inverted for unlimited creativity. Unique and crazy warped effects like lag, slew or portamento can be applied to control voltages perfect for use with a sequencer, or synth keyboard. Up to 4 control voltages can be combined to generate even more complex modulations.

Features:

• Algebraic sound processor modelled after Buchla's models 257 and 281 from the '60s
• Performs a wide range of linear, logarithmic and exponential triggered or continuous functions
• Generates musical envelopes or LFO signals up to 25 minutes and as fast as 1 kHz

Specs:

• 20 HP
• 60 mA +12 V
• 50 mA -12 V

Video: https://youtu.be/XJtpzysqJv8

Product Specs

• Item Number: 32337
• Make: Behringer
• Model: Abacus
• Condition: Excellent
• Finish: Black
• Categories: keyboards-and-synths ⇒ eurorack
• Function: CV Modulation Envelope Follower Envelope Generator Function Generator LFO Slew Limiter
• Made In: China
• MPN: 32337
• Modular Grid: Eurorack ⓘ ＋
• Dimensions*: 20 HP 24 mm deep
• Power*: 60 mA +12V 50 mA -12V 0 mA 5V

* User contributed details