Doepfer A-121-2 12db Multimode Filter

Module A-121 is a voltage-controlled multi-mode filter with a cut-off slope of -12 dB / octave. Four simultaneous outputs are available, each with different characteristics: low-pass, band-pass, high-pass and notch (or band reject). The cut-off frequency determines the point at which the respective filter effects appear. The frequency can be adjusted manually, or by voltage control (Filter modulation, for instance by an LFO or ADSR). Two CV inputs are available, whose control voltages are summed. Resonance (Emphasis or Q ) can be adjusted manually, or by voltage control, right up to self-oscillation, in which case it will behave like a sine wave oscillator.

Technical notes: Module A-121-2 is the successor of the obsolete module A-121. But the circuitry is totally different from the A-121 which used the obsolete CEM3320 filter circuit. The sound of the new module A-121-2 is identical to filter of the Dark Energy II but  has been expanded by the voltage controlled resonance feature.

he custom version is only a design study made with a self adhesive foil printed by a color laser printer. There are no plans to offer this version of the module. But you may use the Coreldraw file on our website A100_System.cdr to design your own front panel. It includes all currently available front panels and you may add your own background or change the size, font or color of the lines, words and symbols. That way a personal module custom module can be realized by printig the design on an self adhesive foil (e.g. Avery Zweckform 3480) and stick the foil to the module. For this the module has to be dismantled. Knobs in different colors are also available (please refer to the price list, section A-100 accessories).

Breite/Width: 8 TE / 8 HP / 40.3 mm
Tiefe/Depth: 50 mm (gemessen ab der Rückseite der Frontplatte / measured from the rear side of the front panel)
Strombedarf/Current: +40mA (+12V) / -40mA (-12V)