DOEPFER / A-121d DUAL MULTIMODE FILTER

Variations

The A-121d is a dual multimode filter that can be used as a dual mono filter with parallel or serial outputs, but is also intended for use with stereo outputs.

The filter consists of two special circuits: "Highpass & Bandpass Output" and "Lowpass & Bandpass Output". This is a feature that has not been available in the A-100 filter module series so far.

Easy use of manual control and CV input for dual filter applications is emphasized. There is a common control for the frequency of both filters (Frequ.) and a control for their difference (Delta, filter spread).

CV inputs (FCV, DCV) are also available for both parameters. Resonance (Q1, Q2), the amount of each FCV input (FCV1, FCV2) and the level of the audio input (In1, In2) are adjusted with individual controls for each filter. ?

The module has a simple audio mixing unit with inputs Mx1 and Mx2 and an output MxO. If you do not patch to the mixer inputs, Bandpass 1 and Bandpass 2 are internally wired to the Mx1 and Mx2 terminals. This allows you to realize any filter type by connecting the other filter outputs (H1 = High Pass 1, L2 = Low Pass 2) to the mixer input. For more information, see the diagram below showing all possible filter types.

You can also combine two or more modules to create, for example, four or more parallel-wired bandpass filters.

Width 8HP
Depth 45mm
Current consumption +12V : 30mA
-12V : 30mA