Analog Multimode Filter with Feedback Insert

The RS-110N is a resonant analog filter offering four simultaneous output modes and a dedicated insert path within its internal feedback loop.

This module provides 24dB low-pass, 24dB high-pass, 12dB band-pass, and 12dB notch outputs running concurrently from a dual-input mixer. Beyond standard frequency sweeps, its defining feature is a dedicated feedback break-out section that routes the resonance loop out of the panel before returning it to the filter core.

In use, the feedback insert fundamentally changes how the filter self-oscillates and saturates. Patching an external delay, distortion, or pitch shifter into the feedback path introduces unpredictable harmonic movement directly into the resonance ring. You can also self-patch the filter outputs, such as routing the notch tap directly back into the feedback return, to shift the circuit into aggressive, metallic self-oscillation.

The dual audio inputs feature significant head-room gain past unity. Driving signals beyond the center threshold adds rich analog overdrive directly at the input stage, which helps smooth out sharp resonance peaks during deep sweeps.