Filter – Audio Damage Mangleverb User Manual
Page 7
The switch labeled PRE and POST changes the signal path within Mangleverb. If the switch is set to PRE, the
reverb comes before the filter and VCA. If the switch is set to POST, the signal passes through the filter and
VCA before entering the reverb.
Filter
Second from the left you’ll find Mangleverb’s filter controls. Since the cutoff
frequency is the most important parameter of a musical filter, these controls are
dominated by the large and uniquely decorated CUTOFF knob. Turn this knob
clockwise to raise the filter’s frequency, turn it anti-clockwise to lower the
frequency.
The other control which is probably familiar to you is the resonance knob, labeled
Q
1
. Turning up the Q knob will cause the filter to boost signals near the cutoff
frequency. If you turn it up far enough, the filter will oscillate, creating a
continuous tone and pretty much obliterating whatever input signal you’re feeding
to it.
The filter operates in one of three different configurations, which you choose with
the TYPE switch. There are three types available:
Low-Pass Filter (LPF) – the type of filter most commonly found in
synthesizers, the low-pass filter attenuates frequencies higher than the
cutoff frequency, passing lower frequencies.
High-Pass Filter (HPF) – the high-pass filter does the opposite: it attenuates frequencies lower than
the cutoff frequency, passing higher frequencies.
Band-Pass Filter (BPF) – the band-pass filter is like a combination of a low-pass and high-pass filter: it
passes frequencies near the cutoff frequency, and attenuates higher and lower frequencies.
Mangleverb’s filters are models of the filters found in a much-revered analog synthesizer of yesteryear whose
name might have the number 20 in it. Like the originals, they distort signals that pass through them,
particularly when driven hard with a loud signal. Since this sort of distortion is often a useful tone-shaping
1
Why Q? According to Wikipedia,
it originated during early work with inductors (coils
of wire used to build filters) and was chosen because all of the other letters in the alphabet were taken for designating other
electrical parameters. Yes, really.