Doepfer A-101-6 Opto FET VCF/Phaser

The Doepfer A-101-6 is a unique and flexible Eurorack module that blends the functionality of a voltage-controlled filter and a phaser using opto-FETs. Unlike traditional vactrol-based designs, opto-FETs offer faster response times and reduced noise, resulting in a clean yet characterful modulation path.

With six opto-FET stages, the module can operate as a 6-pole lowpass filter or as a dynamic phaser. The feedback control (resonance) adds depth and motion, while CV inputs allow for animated movement across the spectrum. Perfect for psychedelic textures, subtle modulation, or wild filtering sweeps.

Key Features:

• Opto-FET-based voltage-controlled phaser/VCF

• 6-stage architecture for rich, evolving sound

• Feedback (resonance) for tonal shaping

• Voltage control over frequency and feedback

• Great for dynamic filtering and spatial modulation