ALM Busy Circuits MUM M8

S950-inspired low-pass filter with smooth vacuum-like tone and aggressive resonance.

8 HP Eurorack module

An 8 HP Eurorack low-pass filter based on the Akai S950 sampler filter design, with resonance, voltage control, clipped saturation, and a dedicated VCA.

Features

• Dual cutoff CV control, including attenuation and inversion on the main CV input, plus resonance CV control.
• Two audio inputs, with a dedicated VCA on one input that can drive the filter core.
• Aggressive resonance capable of self-oscillation past noon.

Controls & Jacks (13)

• VCA Level— Sets the level of the VCA Audio Input when no VCA CV is patched, or attenuates VCA CV when it is patched.
• Resonance CV Attenuator— Sets the amount of resonance CV applied from the Resonance CV Input.
• Frequency CV Attenuverter— Attenuverter for the lower frequency CV input, providing attenuation and inversion of its cutoff modulation.
• Frequency CV Input 2— Second cutoff-frequency CV input with no attenuation.
• Resonance CV Input— CV input for resonance, controlled by the associated resonance CV attenuator.
• Resonance— Manual offset control for filter resonance; settings beyond approximately noon can self-oscillate.
• VCA Audio Input— Audio input routed through the VCA before being mixed into the filter; its level is set by the VCA Level control or its CV attenuator.
• Filter Output— Low-pass filter audio output.
• VCA CV Input— CV input for the dedicated input VCA.
• Audio Input— Direct audio input mixed with the VCA audio input before the filter.
• Cutoff— Manual offset control for the filter cutoff frequency.
• Frequency CV Input— Primary cutoff-frequency CV input, summed with the manual cutoff control and other frequency CV input.
• Clip— Indicates clipping at the filter input.

How-To Guides

• Patch audio through the filter

Explore the interactive MUM M8 panel on BleepDex — tap any control to learn what it does.