Plus Legio#

Complete additive voice with internal modulation

Overview#

Plus Legio is a complete additive synth voice with simple envelope control and a complex internal modulation matrix. Timbre controls the levels of the additive oscillators, which can also be modulated by the internal ADSR envelope by way of the Mod switch. An optional chorus LFO brings width and movement to a sound, which can, in turn, be modulated by the ADSR envelope for extra complex and evolving notes. Add in stereo phase-modulation inputs and you've got a wildly complex synth voice that's easy to control, all in 6 HP!

  • Type: Additive voice
  • Size: 6 HP
  • Depth: 1.5 inches
  • Power: 2x5 Eurorack
  • +12 V: 140mA
  • -12 V: 22mA

Etymology#

Plus -- from Latin: "More”

Legio -- from Latin: “legion, army”

“Lots More”

Color code#

On boot, the Legio's LEDs will shine with this color pattern to indicate that it is running the current Bitcrush firmware:

A illustration of two lights: blue and blue.

Power#

Power connector

To power your Noise Engineering module, turn off your case. Plug one end of your ribbon cable into your power board so that the red stripe on the ribbon cable is aligned to the side that says -12 V and each pin on the power header is plugged into the connector on the ribbon. Make sure no pins are overhanging the connector! If they are, unplug it and realign.

Line up the red stripe on the ribbon cable so that it matches the white stripe and/or -12 V indication on the board and plug in the connector.

Screw your module into your case before powering on the module. You risk bumping the module's PCB against something metallic and damaging it if it's not properly secured when powered on.

You should be good to go if you followed these instructions. Now go make some noise!

Noise Engineering modules are reverse protected. If you accidentally installed it with the red stripe up, simply remove the power and place it correctly.

A final note. Some modules have other headers -- they may have a different number of pins or may say "not power". In general, unless a manual tells you otherwise, do not connect those to power.

Input & output voltages#

Legio’s CV-modulation inputs expect signals from 0v to +5v.

The Pitch input’s range is -2v to +5v.

The Hit input responds to a rising edge around +1.6v.

The audio inputs are AC coupled and respond to any Eurorack audio signals.

The audio output can reach up to 16v peak-to-peak.

Interface#

explanation

Pitch (encoder+CV input)
Sets the pitch of the voice. Turn for fine tuning, press and turn for coarse tuning.
Time (potentiometer+CV input)
Sets the relative time of the ADSR envelope segments that control the dynamics of the voice (and, optionally, the amplitude of the LFO).
Timbre (potentiometer+CV input)
Sets the levels of the additive oscillators.
Mod (switch)
Sets the direction for Timbre modulation from the envelope.
  • +: Positive modulation.
  • Off: No envelope modulation.
  • -: Negative modulation.

Note

Envelope modulation is offset by the Timbre parameter. In order to hear negative modulation, Timbre must be above minimum, and to hear positive modulation, Timbre must be below maximum.

LFO (switch)
Controls a chorus LFO.
  • Env: LFO rate is modulated by the ADSR envelope.
  • On: LFO is always on.
  • Off: LFO is off.
Hit (gate input)
Gate/trigger input for the ADSR envelope.
PM L/R
Phase-modulation inputs. The L jack is normaled to the R jack if R is left unpatched.
Out L/Out R
Audio outputs.

Patch tutorial#

Patch a pitch-CV sequence to the Pitch input, and a trigger/gate sequence to Hit.

Set Mod and LFO to the Offpositions.

Adjust Time to taste, and use Timbre to adjust how the voice sounds.

Set Mod to positive, and try out the LFO settings to add some movement to your sound.

Patch another oscillator to a PM input for even more timbral range.

Signal flow#

A block diagram of the firmware's signal flow.

Warranty#

We will repair or replace (at our discretion) any product that we manufactured for one year after initial purchase as long as we are able to get the parts to do so. This warranty does not apply to normal wear and tear, including art/panel wear, or any products that have been modified, abused, or misused. Our warranty is limited to manufacturing defects.

Warranty repairs/replacements are free. Repairs due to normal wear, user modification, or other damage are charged at an affordable rate. Customers are responsible for the cost of shipping to Noise Engineering technicians for repair.

All returns must be coordinated through Noise Engineering; returns without a Return Authorization will be refused and returned to sender.

For immediate issues with new modules, please contact your dealer for a replacement. Otherwise, please contact us if you think one of your modules needs a repair.

Design Notes#

We've long been fans of additive synthesis and the goal with Plus was to make an easy-to-use additive voice that sounds great. Legio allowed us to do that in a small footprint.

Special thanks#

  • Enthusiastic Electrons
  • Everett Dolgner
  • Frequency Divide
  • itsMasterIll
  • Ozon
  • starthief