Doepfer A-106-5 SEM VCF

The Doepfer A-106-5 SEM VCF is a 12 dB multimode filter that is based on the filter circuit of the Oberheim SEM module. The filter is equipped with a band pass output and a combined low/notch/high pass output. For this output a control knob defines the relation between low and high pass signal. If both signals appear at the same level (i.e. middle position of the Mix knob) one obtains a notch filter. Otherwise the low or high pass signal predominates. The module does not feature self oscillation in contrast to most of the other filters of the A-100 system. The module generates a distorted audio signal if the level control is set to about 50% (i.e. center position) or more with A-100 standard signals like VCOs.

The function and operation of this module is very similar to the Wasp filter module A-124. But the sound of both filters is very different. The only functional difference is the position of the sockets and controls, and the function of the controls CV2 (A-124: normal attenuator, A-106-5: polarizer).

Features:

• Inputs: Audio In, CV1 In without attenuator, CV2 In with Polarizer
• Outputs: Bandpass Out, Low/Highpass Mix-Out
• Controls: Audio Attenuator, CV2 Polarizer, Frequency, Resonance, LP/HP Mix