0HP Modular

Whether you need some extra utilities for your studio behemoth or you need to save space on the road, 0HP gives you options.  Our modules come as a small circuit board mounted to a colorful piece of laser cut plexiglass, with a small chance to get one of our fabulous rare colors.  With a robust line of modules planned in the future, full DIY kits and an open hardware licence we aim to make modular synthesis accessible and fun for the veteran and new user alike.


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 or any of our retailers assume NO RESPONSIBILITY for modules that are accidentally damaged by doing so.  This expectation follows 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.

NOTE: For information on building the DIY options please go here.


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.

EYEtenuator Assembled: $33

EYEtenuator Full Kit (PREORDER): $23

EYEtenuator PCB and Panel: $10

EYEtenuator PCB Only: $5

0HP Vactrol LPG/ VCA

0HP Vactrol based modules take advantage of an outdated part to rough the edges of your sound.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 Voltage Controlled Amplifier 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 different response curve.

Vactrol VCA assembled: $33

Vactrol LPG assembled: $33

Vactrol VCA full kit: $23 (out of stock)

Vactrol LPG full kit: $23 (out of stock)

Vactrol VCA/ LPG PCB with acylic backing: $10
(both modules use same circuit board)

Vactrol VCA/ LPG PCB only: $5
(both modules use same circuit board)

0HP AND Gate - VCA:

The 0HP VCA/ AND 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.

AND Gate/ VCA assembled: $33

AND Gate/ VCA full kit: $23 (out of stock)

AND Gate/ VCA circuit board with acrylic backing: $10

AND Gate/ VCA circuit board only: $5

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.

OR Gate assembled: $33

OR Gate full kit: $23 (out of stock)

OR Gate circuit board with acrylic backing: $10

OR Gate circuit board only: $5