Doepfer A-105-2 SSI Low Pass Filter

The Doepfer A-105-2 is a voltage-controlled 24dB/oct low-pass filter built around the SSI2144 chip, offering the smooth, rich character of classic synths like the Korg Polysix and EMu SP-1200. It’s a modern successor to the original A-105, retaining its sonic signature while reducing the footprint to just 4HP.

The module features two audio inputs mixed pre-filter, with adjustable level for input 1. Cutoff and resonance are both manually and CV-controllable, with attenuators on the second frequency CV input and the resonance CV input. The filter self-oscillates at high resonance settings, allowing it to be used as a sine wave source.

Despite the slimmer layout, all core functions remain intact, making the A-105-2 a flexible and great-sounding option for filtering duties in smaller systems.

Key Features

• 4HP width

• 24dB/oct low-pass filter based on the SSI2144 chip

• Successor to the original SSM2044-based A-105

• Resonance reaches self-oscillation

• Two audio inputs mixed pre-filter

• Input 1 level adjustable via knob

• CV control over cutoff and resonance

• Attenuators on FCV2 and QCV inputs

• Frequency range approx. 15 Hz – 15 kHz

• Compact layout for small systems

• Available in-store for demo