DOEPFER / A-106-6V Xpander Type VCF / 16

Variations

The A-106-6 XP VCF 16 Fold VC Xpander Filter is a multimode filter based on the Oberheim Xpander filter circuit.

This module contains 15 different filters, 8 of which can be used simultaneously. The toggle switch Filter Group toggles between two filter groups.

List of Filter Types
1L (6 dB low pass)
2L (12 dB low pass)
3L (18 dB low pass)
4L (24 dB low pass)
1H (6 dB high pass)
2H (12 dB high pass)
3H (18 dB high pass)
2B (6 dB band pass)
4B (12 dB band pass)
2N (notch)
3A ( All-pass)
2H1L (asymmetric bandpass with 12 dB high pass and 6 dB low pass)
3H1L (asymmetric bandpass with 18 dB high pass and 6 dB low pass)
2N1L (combination of notch and 6 dB low pass)
3A1L (combination of all pass and 6 dB low pass)
VC resonance function; Filter Group 2 (2L, 4L, 2B...) is also capable of self-oscillation.

All standard VCF controls are available. Manual Filter Frequency Control (Frq.), CV input with attenuator (FCV2) and CV input without attenuator (FCV1,?1V/Oct). It also has a manually controlled VC resonance (Q) and an attenuated CV input (QCV).

The circuit is based on a 24dB low-pass filter: the outputs of the four internal filter stages (6, 12, 18, and 24dB outputs) are mixed at different levels and polarities to produce 15 different filter sounds. Due to this special circuitry, the outputs have slightly different levels and noise floors. This is due to the different number of internal amplifiers and stages required to generate the filters. For example, a filter generated with only one stage, such as a 6dB, 12dB, 18dB, or 24dB low pass, will have a smaller noise floor than a filter with all four stages combined.

Width 12HP
Depth 50mm
Current consumption
+12V : 50mA
-12V : 50mA