You hear many users search for an “extreme” filter to add to their system, looking for one that is unstable when pushed, screams when provoked, and otherwise makes their instrument more aggressive, less predictable, and in general fun to play with (if you’re the type of person who likes to play with knives). Filters based on the Vladimir Kuzmin’s design in the Russian Polivoks synthesizer fit this description. My favorite variation of the classic Polivoks design in the Erica Dtech VCF, which extends the original design. In this video, I explore how to push the Dtech filter into unstable, aggressive territory
This module – a recreation of the classic Serge Wave Multipliers (VCM) module from the early 80s, adapted partially to the Eurorack format – contains a nicely-rounded, tube-like clipping or saturation; a wave folder that emphasized the odd-numbered harmonics; and a three-stage full wave rectifier that emphasizes the even harmonics. The video in this article focuses on the wave shaping section, and compares its analog sound to the digital one included in the Expert Sleepers Disting; I also discuss matching Eurorack levels to work with Serge-inspired modules.
One of the potential challenges of using a modular synth is keeping multiple VCOs in tune with each other as well as external instruments as you play up and down a scale. Most VCOs have trim controls to improve their tracking, but they can occasionally be frustrating to use: They may require you to remove the module from the case to access them, or the manufacturer might have not have used high-precision multi-turn potentiometers for the trimming controls. Therefore, I’ve added several AJH Synth V-Scale Variable Precision Buffers to my modular cases, and have been happier for it. What sets it apart is that 4 of its 5 outputs have high-precision trimmers accessible from the front panel, allowing you to improve the tracking of connected modules like VCOs and resonating filters.
A nice option for an analog VCO to add to your system is the Intellijel Dixie II+: it’s small, has excellent tracking, supports linear and exponential FM as well as PWM and hard sync, and has six different waveforms. In this movie, I demonstrate creating a hard sync patch with the Dixie II+. For those who wonder exactly what’s going on when you use sync, I focus heavily on what’s happening with the waveform output. I also look at the Dixie II+’s unique Flip function.