Doepfer A-126-2 Frequency Shifter

The Doepfer A-126-2 is a fully analog frequency shifter designed for audio-rate modulation and experimental sound shaping. Unlike a pitch shifter, which transposes audio proportionally, a frequency shifter displaces every frequency in the input signal by a fixed amount — producing inharmonic, metallic, and bell-like tones that can’t be achieved with conventional modulation tools.

At its core, the A-126-2 uses a high-precision 12-stage Dome filter, a quadrature oscillator, and dual analog ring modulators to shift frequencies up or down — or anywhere in between — with full voltage control over the shift amount and mix. The result is a rich and unusual palette of phase-shifted, harmonically detuned, or totally alien sounds.

Equipped with both manual and CV control over shift frequency, up/down mix, and squelch behavior, this module excels in stereo imaging, sideband filtering, chaotic FX, and deep drone manipulation. It even features internal VCA squelching, envelope following, and direct outputs for Up, Down, and Ring Mod signals—making it an excellent modulation destination or audio mangler.

Use the built-in quadrature oscillator, or patch in external sources like the A-110-4 or A-143-9 for extended frequency ranges or different waveforms. With precise build quality and an all-through-hole design, the A-126-2 is a durable and high-performance frequency shifter for creative modular systems.

Version 2 includes an internal header for Audio Input 2, expanding feedback possibilities when paired with the optional A-126-2Exp module.