MFB FilterBox User manual

General
The MFB-FilterBox is an analogue filter unit with an integrated
stepsequencer with up to eight steps. It processes stereo as well as
monaural signals.
Setup
Connect the included power supply into the POWER jack. AUDIO OUT
is a TRS jack that connects to your amplifier or mixing console. AUDIO
IN is the FilterBox’ stereo input, once again on a TRS jack.
MIDI IN connects to the output of a MIDI sync source, e.g. a drum
computer or a keyboard. Finally, switch on the MFB-FilterBox by
pressing its ON/OFF button.
Function
Audio signal is routed into a resonant stereo lowpass-filter with 24
dB/oct slope. It’s directly routing to the output from here. Here’s a
description of the controls in detail:
ON/OFF
Press this button to switch the MFB-FilterBox on or off.
MIDI
Press and hold MIDI while using the data encoder to set the MIDI
channel.
Trigger
Press and hold TRIGGER and use the data encoder to switch between
five different trigger modi:
1 Internal sync
2 Sync to play
3 MIDI clock sync 1/16th note
4 MIDI clock sync 1/8th note
5 MIDI clock sync 1/4th note
6 Bar sync by MIDI note on
7 Keyboard sequence control (C2,D2,...C3 = Cutoff 1..8)
Input
This control sets the gain of the audio input. Signal levels above 1 Vss
will introduce distortion that can be used as an overdrive effect.
Step
Press and hold STEP while using the data encoder to set the length of
the sequence between 1-8 steps.
Step 1-Step 8
Use these controls to set different cutoff frequencies for each sequencer
step. Whenever the sequencer stops, only control 1 is active. The
controls address both sides of the stereo filter.
Play
Use PLAY to start and stop the sequence in trigger mode 1. In trigger
mod 2 PLAY will trigger the individual steps.
Tempo
The TEMPO control adjusts the sequence tempo in trigger mode 1.
Glide
By turning GLIDE clockwise the stepping of the filter sequence turn into
a continuous glide between the values.
Emphasis
EMPHASIS controls the resonance/feedback of the filter, a peak at the
cutoff frequency. It works up to self-oscillation.
Space
Use SPACE to set a difference in cutoff frequency for the left and right
stereo channel.
Threshold
This control sets the trigger threshold for the audio input. The trigger
itself will start the Attack/Decay envelope.

Contour
CONTOUR sets the modulation amount of the Attack/Decay envelope
to the stereo filter with full modulation at the center position. Turn
counter clockwise from here to decrease cutoff frequency, turn
clockwise to raise the cutoff frequency.
Attack
ATTACK controls the time the filter envelope takes to reach its full
modulation amount.
Decay
DECAY controls the time the filter envelope takes to travel from full
modulation to zero modulation amount.
Midi In
While in trigger mode 3, 4 and 5 the sequencer is controlled by Midi
Start/Stop and MIDI clock.
In trigger mode 6 it is controlled with Start/Stop and any MIDI Note On
command.
Trigger mode 7 allows to access the individual cutoff step controls with
note numbers C2, D2, E2, F2, G2, A2, H2 and C3.
Operating manual
MFB-FilterBox