Effects

Katla features two stereo effects: a lush reverb inspired by iconic 1980s hardware, routed through a ferocious CMOS drive.

CMOS Drive

CMOS Drive is an analog distortion circuit built around CMOS inverter chips, normally used for digital logic rather than audio. When overdriven, these MOSFET-based inverters transition through their linear region and produce a distinct, harmonically rich clipping response that differs from typical diode or op-amp based distortion effects. The result is a sharp, responsive distortion character with strong dynamic interaction, making CMOS stages useful for adding aggressive edge, asymmetric saturation, and unique timbral shifts to an audio signal.

Reverb Amount

This slider controls a combination of reverb parameters, including reverb length, modulation depth, and stereo width. At its lowest setting, the reverb has a short tail, minimal modulation, and a narrow stereo image. At its highest setting, the tail becomes longer, modulation depth increases, and the stereo field widens.

Reverb Mix

Controls the reverb dry/wet mix.

Drive Amount

Controls the input level for the CMOS drive — higher levels produce more distortion.

Drive Mix

Controls the drive dry/wet mix.

Effects Color

This slider affects both the reverb and the drive in different ways to shape their perceived brightness. In the reverb, it adjusts several parameters within the algorithm, including a tank filter and a tilt EQ. In the drive, the Effects Color slider controls a mid-scoop filter by shifting the frequency of the dip. When modulated, it can produce a phaser-like effect.