Mystic Circuits is known for some far out module design, like their extremely fun gate sequencer, Vert. Now Eli and the Mystic Circuits team have developed a new floating module system in the tradition of external mults, called 0HP. These innovative, business card sized modules dangle from or rest on your eurorack system, performing basic but crucial functions.

0HP “modules” are ingenious. Simple passive circuits (requiring no additional power source) rest at the heart of these open source devices. Available assembled or in DIY kit form, the 0HP line provide important tools that any modular user might need.

We all need more VCAs. Perhaps the most useful device in the line is the VCA/AND Gate, a passive VCA with an additional trigger output. When a signal is patched to the input, AND the CV input recieves a high voltage, the signal is sent to the output. With a gate, we get the AND logic functionality. When an envelope is used instead, we can shape the amplitude of the input signal over time. The circuit might be passive, but it can handle audio rate modulation, applying amplitude modulation to the incoming signal for some deep tonal manipulation.

The OR gate is another handy device, combining two CV or gate signals to a single output. This circuit can be used as a simple mixer with no attenuation, making it useful for many purposes. The module works well as a gate sequence mixer as well, allowing the signals from both input 1 OR input 2 to pass to the output, a fun tool for combining a steady a pattern with a more complex one for fills or embellishments.

Mystic Circuits has just released two more 0HP modules, a vactrol based VCA and a vactrol based low pass gate, offering more options for shaping the character of your patches without the cost in rackable modules.

What external devices are you using with your modular system? Tell us about it in the comments!