Mum M8 S950 Lowpass Filter

ALM Busy Circuits MUM M8

ALM Busy Circuits presents MUM M8', an 8hp lowpass filter built from the same design as that of the Akai S950, albeit with the incorporation of voltage control, resonance, clipped saturation, and a VCA. The filter can be driven to self-oscillation at higher resonance levels, while its clipped overdrive works in tandem to its smooth core to push it into wasp-esque territory that affords a distinctly varied sound.

Mum8's filter cutoff enjoys dual voltage control with attenuation and inversion, and its resonance can operate under full voltage control. Beyond that, one of the module's inputs features an integrated VCA, which can be used to compound overdriven signals into the filter core.

Though the filter is analog, it is driven by a digital clock. This combination results in a characteristically smooth sound with high minimum cutoff that prevents any clock bleed. The cutoff point can be configured via trimmers on the reverse side, though there will still be some low-level artifacts present—which only adds to the filter's already distinct character.

MUM M8 Features

• Modeled after the Akai S950 filter design
• 6th Order Butterworth switched capacitor type filter design
• Analog core controlled by high speed digital clock
• High resonance yields self-oscillation
• Two audio inputs, one with VCA