ARTURIA – ARP2600– USER’S MANUAL 67
The ARP2600 V noise module
6.1.2 The filter or VCF
The audio signal generated by an oscillator (the waveform) is next generally directed to a
filter module (Voltage Controlled Filter). It is this module that we use to control the
sound by filtering (by subtraction, which explains the name given to this type of
synthesis) the harmonics situated around a cut-off frequency. It can be considered to be
a sophisticated equalizer that reduces, depending on the case, the high or low
frequencies of a sound.
The removal of undesirable frequencies at the cut-off frequency is not done suddenly but
progressively, depending on the filtering slope. This filtering slope is expressed in
decibels per octave (or dB/Oct). The filters used in classic analog synthesizers have 24
dB/Oct or 12 dB/Oct slopes.
The ARP2600 V filter module
The ARP 2600 V offers two types of slope: 24 and 12 dB/Oct slopes.
On the ARP2600 V, you have access to four types of filtering. Let’s have a look at some
of his properties:
The low-pass filter (LPF) progressively removes high frequencies above the
assigned frequency limit (the cut-off frequency) and allows the sound below the cut-