Whether you need some extra utilities for your studio behemoth or you need to save space on the road, 0HP gives you options! These modules are all passive designs that come as a small circuit board mounted inside a neat purple case which can float anywhere around your modular system.
More 0HP videos can be found here: Mystic Circuits on Youtube
0HP – Envelope
Don’t let the name fool you, this module is quite a bit more than just an envelope. Patch in a gate and your output will behave as a normal sustain- release envelope, staying high while the gate is high and slowly decaying once it goes low. Patch in audio and you have an envelope follower, extracting amplitude data from whatever signal is coming in. Patch in any positive control voltage and you have a slew, adding glide whenever the incoming voltage falls. All three modes boast voltage control over the release/ response time and can use the on board input mult to either daisy chain multiple envelopes or to extract amplitude data from an audio input and then send the audio somewhere else. Possibly the most useful 0HP module yet!
Envelope: Video Build Tutorial
0HP – Vactrol Low Pass Gate / Vactrol VCA
Both of the Vactrol based modules use the same PCB design but involve slightly different components. 0HP Vactrol based modules take advantage of an outdated part to rough the edges of your sound. What sets Vactrol-based circuits apart is that they will slow down any incoming control voltages, allowing them to convert a gate or trigger CV input into very musical envelopes. Both the Vactrol Low Pass Gate and the Vactrol VCA modulate the amplitude of a signal under voltage control, but the VCA does so with minimal alteration to the sound whereas the LPG filters the sound to give it some extra weight. Both modules feature a ‘mix input’ allowing for passive mixing with other sound sources or daisy chaining of multiple Vactrol modules. Please note that all Vactrols are unique snowflakes and as such each module will have a slightly different response curve.
0HP – AND Gate (& VCA)
The 0HP VCA/ AND gate acts like a faucet: When a high control voltage is present, the input is allowed to flow to the output. When there is a low control voltage, the flow is restricted and nothing is present at the output. Using a high speed optocoupler, the module accepts audio at all inputs so audio-rate amplitude modulation is possible for pseudo-ring modulation effects. When used with gates at both the input and the CV input, the module acts as a logical AND gate (an AND gate outputs a high voltage when both of the inputs are high.) A built in trigger converter outputs spike whenever the main output transitions from low to high.
0HP – OR Gate
The 0HP OR Gate can be used to combine different signals, usually gate or clock signals. The output will give a high voltage whenever a high voltage is present at either of the inputs. This can be useful for combining multiple different gate sources together to trigger the same module, such as using a gate sequencer and a burst generator on a drum module to get drum fills. This module can also process fluctuating voltages, outputting the maximum of the two inputs (the highest of the input voltages above 0). The built in trigger converter outputs a spike whenever the main output transitions from low to high.
0HP – 0ttenuator
Two interconnected attenuators that can perform a variety of mixing functions without taking space or power in the rack. Mix, pan or use each attenuator separately. The 0ttenuator can:
- Mix two signals together
- Send one signal to two places
- Attenuate two signals separately
Be advised that even when the knobs are all the way up there is a little bit of signal loss.
0HP – Eyetenuator
Control your synth with the power of light! Two signals coming through this 0HP module are attenuated based on the amount of light hitting their respective photo detector. Normalized jacks allow one input to be sent to each attenuator or for both attenuators to be summed together at one output.
Since the modules are passive, some signal loss and distortion should be expected. The user is expected to keep cables away from the top of the circuit board. While in 99.9% of cases an accidental short circuit is not an issue, Mystic Circuits, Eli Pechman and Thonk assume NO RESPONSIBILITY for modules that are accidentally damaged by doing so. This expectation follows the same logic as not plugging an output into another output or touching your cables to the panels, which are common safety practices expected to be followed by the end user.