Krautrock Phaser is a stereo phaser built around a faithful emulation of the Schulte Compact Phasing “A”, the unit heard on classic Krautrock, kosmische, and early electronic recordings.
Eight first-order all-pass sections share a single LFO, producing four evenly-spaced notches that sweep together through the frequency spectrum. The result is a dense, harmonically rich sweep — less like a filter and more like the sound moving through physical space. Feedback is tapped after stage 2, meaning only the first two stages feed back into the input. This creates a tight, resonant peak low in the sweep that gives the phaser its characteristic bite and voice: the “wah-like” quality that distinguishes the Schulte from smoother, more diffuse phasers.
The lamp model gives the sweep a slightly lopsided, breathing quality. It rises faster than it falls, the way a real incandescent bulb responds to current. The result is a modulation that feels organic and unpredictable rather than mechanical. The Bias control determines how deep the sweep travels: lower values open it up into a wide, dramatic arc; higher values pull it back into something subtler and more continuous.
Two stereo modes:
Hardware — shared LFO and coefficient across both channels, faithful to the original character
Dual LFO — independent LFOs offset 180°, for a wider, more animated stereo sweep.
Available for macOS (AU, VST3, CLAP) · Windows (VST3, CLAP) · Linux (VST3, CLAP)
Need help installing? See our Installation Guide.