Doepfer A-124 Wasp Filter

The Doepfer A-124 Wasp Filter (Silver) is a character-rich multimode filter that captures the snarling spirit of the iconic EDP Wasp synthesizer from the late 1970s. Its secret weapon? A deliberately unorthodox design that uses CMOS inverters instead of op-amps—introducing instability and saturation in all the right ways.

This 12 dB/oct filter features a bandpass output and a mix output that lets you continuously blend between lowpass, notch, and highpass modes. The resonance is aggressive and unpredictable—never reaching full self-oscillation but always flirting with feedback. Crank the input gain for signal distortion and raw sonic texture.

If you want a filter that adds bite, dirt, and eccentricity to your patches, the A-124 delivers with flair. A classic Doepfer favourite with a rebellious edge.

Key Features:

• Multimode filter with 12 dB/oct slope

• Blendable lowpass, notch, and highpass via Mix control

• Dedicated bandpass output

• Unstable resonance with strong character

• Input gain for distortion and tone shaping

• CMOS inverter-based circuit inspired by the EDP Wasp

• Silver faceplate with full-size knobs