ALM Busy Circuits

Beast's Chalkboard


Beast’s Chalkboard is dual channel stepped voltage source and adder for your eurorack modular synthesizer system. It can also function as a dual precision buffered mult. 

It primarily is intended as a dual octave switcher for VCO’s but has many other uses including sequence transposition, FM ratio creation, buffered CV distribution and VCO calibration.


    • Dual channel voltage adder and source with 1V stepped range of -2 to +2 volts (i.e 5 Octaves)
    • Two Buffered outputs and through output per channel
    • Top input normalized to bottom. Allows input to be varied across both channel outputs
    • Bottom octave switcher can be chained to top extending range to 9 octaves
    • Also functions as 1->6 or dual 1->3 buffered mult.
    • Skiff friendly
    • Designed and built in England.


    • Width: 6HP
    • Max Depth: 22mm
    • Power: 30mA @+12V , 30mA @-12V , 0mA @+5V