Doepfer A-120

24 dB Low Pass 1 (VCF1)

Module A-120 is a voltage-controlled 24 dB low-pass filter, which filters out the high frequency components from a sound spectrum while allowing the low frequencies to pass unhindered. The cut-off frequency (corner frequency) determines the point at which this effect occurs. They can be set or modulated both manually and via control voltages (filter modulation, with an LFO for example). The VCF1 is configured as a "transistor cascade" with an edge slope of -24 dB / octave, which is also used in various Moog synthesizers, This results in the typical, "legendary" Moog sound. The resonance (emphasis) can be adjusted at the VCF 1 to the point of self-oscillation. In this case, the filter operates as a sinusoidal oscillator.

• 24 dB low pass 1 (VCF1)
• Voltage-controlled 24 dB low-pass filter
• Width: 8TE / 40.3 mm
• Depth: 65 mm (measured from the back of the front panel)
• Power Requirement: 30mA (12V) / -20mA (-12V)