Jürgen Haible was a German electronics engineer and synthesizer designer who became one of the most respected figures in the DIY synth-building community for his meticulous reverse-engineering and reinterpretation of classic analog circuits. Working largely through self-published schematics and small-run PCBs, he produced a deep catalog of modules and effects that closely studied — and often improved upon — vintage gear from EMS, Moog, ARP, Bode, and the Berlin-school Schulte phaser tradition.

Among his best-known designs are the Krautrock Phaser (a reinterpretation of the Schulte Compact A used heavily by Tangerine Dream and Klaus Schulze), the Tau Phaser, the Living VCO and Living Vocoder (EMS VCS3-inspired), the Frequency Shifter (after Bode), the Storm Tide Flanger, the Trapezoid VCA, and various filters including SSM2040- and Wasp-style designs. His circuits became staples of the MOTM and 5U formats and have since been adapted to Eurorack.

Following Haible's death in 2011, his intellectual property, schematics, and module designs were acquired by Random*Source, which has been steadily reissuing the catalog — beginning with the Krautrock Phaser — and bringing his work to new formats. His designs continue to be built by hobbyists worldwide through licensed PCB vendors such as Modular Addict and Bridechamber.

Jurgen Haible has 2 products cataloged on Equipboard, including Effects Processors. Their gear is featured by 1 artist, with the strongest followings in Electronic. Notable users include Aphex Twin.