Sinc Legio#

Multimode stereo oscillator with wavemorphing, folding, and PM


Sinc Legio is a compact oscillator with some tricks up its proverbial sleeve. If you need some basic waveforms, Sinc has you covered – and it makes it easy to spice up those waveforms with phase modulation, wavefolding, or hard sync. Sinc pairs well with other oscillators in your system, too: hard-sync and stereo PM inputs make complex sounds easy to patch. Combine broad-ranging timbral parameters with a vintage-inspired chorus, and you’re well on your way to stereo sound-design heaven in just 6 HP.

Not only is Sinc an incredible oscillator on its own, it’s also part of the Legio platform. Use the included USB cable to connect to the Customer Portal and swap the firmware to any other Legio firmware, completely free, at any time.

  • Type: Stereo PM oscillator
  • Size: 6HP
  • Depth: 1.5 Inches
  • Power: 2x5 Eurorack
  • +12 V: 140 mA
  • -12 V: 22 mA


Sinc -- from Old English: "treasure"

Legio -- from Latin: "legion"

"Lots of treasure"

Color code#

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

A illustration of two lights. From left to right, the lights are colored green and pink.


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!

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#

Sinc Legio’s CV-modulation inputs expect signals from 0 V to +5 V, except the Pitch input, which has a range of -2 V to +5 V. The Sync input responds to a rising edge around +1.6 V.

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

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


Sinc Legio features an autocalibration system. The modules are autocalibrated and tested at the factory, but should you feel you need to recalibrate, just power the unit on with nothing patched to the Pitch CV input. The module will calibrate itself during startup.


An illustration of Sinc Legio's interface

Pitch (encoder)
Sets the pitch of the oscillator. Turn for fine tuning, press and turn for coarse tuning.
Pitch (CV)
1v/8va calibrated pitch CV input.
Changes the waveform of the oscillator.
Changes the timbre of the oscillator in different ways, depending on the mode.
  • In Warp mode, Timbre controls the pitch of an internal modulation oscillator that applies PM to, and sums with, the carrier oscillator.
  • In Op mode, Timbre controls the level of phase modulation applied to the carrier oscillator from an internal modulation oscillator, and, if patched, the amount of external PM applied to the modulation oscillator.
  • In Fold mode, Timbre controls the amount of wavefolding.
Changes the oscillator algorithm. More info on each algorithm can be found in the section below called Tone Generation.
Activates the vintage-inspired chorus. 0 is off, I is some, II is lots.
Hard-sync input.
Phase-modulation inputs. Intended for use with audio-rate signals for complex harmonic patches, similar in sound to FM.
Inputs can be used independently with separate signals, or with a single signal. Patching to the L input will normal to the right for easy modulation.
Out L/Out R
Audio outputs.

Getting started with Sinc#

Bubbly saws
Set Sinc to Warp mode, the chorus to 0, and adjust Morph and Fold to match the illustration. An illustration of Sinc's settings for this patch'
VC multi-op PM
Patch two or more Sinc Legios in series, input to output. Set all to Op mode, and set chorus to 0. Use the Timbre parameter to change the amount of phase modulation, and the Pitch parameter to change the flavor of the sound. Try voltage controlling Timbre and Pitch with sequencers or envelopes for even more PM fun! An illustration of Sinc's settings for this patch'
Super stereo
Set Sinc to Fold mode, the chorus to I or II, and adjust Morph and Fold to taste. Listen to the glorious magic of stereo sound! An illustration of Sinc's settings for this patch'

Tone Generation#

Sinc Legio has three synthesis algorithms: Warp, Op, and Fold.

Warp uses phase modulation to create its timbres. The modulating oscillator is also mixed with the output oscillator, creating additional amplitude-modulated artifacts that add to the character of the sound. The Morph parameter changes the shape of the output oscillator, and Timbre controls the pitch of the modulating oscillator, perfect for bright and heavily modulated sounds with no patching required.

Op is designed to fit into a broader phase-modulation patch, or create wild self-modulating sounds on its own. Timbre controls the PM index, allowing for voltage control over the amount of modulation – a great target for envelope generators to create FM-style plucks. A single modulation oscillator can be patched to the left input for standard PM duties, or left and right can be PM’d individually for wild stereo experimentation. When no external oscillator is patched to the inputs, Sinc modulates itself for simple and bright in-the-box self PM.

Fold uses the famous Noise Engineering infinifolder to create bright, complex sounds. Use Morph to find a waveshape you like, then fold and distort it with the folder, controlled by the Timbre parameter.

Swapping firmware#

Sinc Legio’s firmware can be updated by the user via our firmware webapp on the Noise Engineering Customer Portal. Alternate firmwares available now transform the Legio into completely different modules, and open-source firmware development documentation is available here.

To swap the firmware on your Legio:

  1. Turn off the power to your case and unscrew the module.

  2. Remove the power connector on the back of the module.

  3. Plug a micro USB connector into the port on the back of the module, and the other end into your computer.

  4. Follow the instructions in the webapp.

Design notes#

Sinc Legio was inspired by the need for a compact oscillator in our lineup. A long time ago we released Sinc Iter, a broad-ranging utility oscillator that had some fun features we really enjoyed. We had to discontinue SI for a variety of unfun reasons, but when we decided to put an oscillator on the Legio platform, we knew we wanted to use its features as a starting point.

It was just a starting point, though, because with the Legio platform, we had twice as many parameters to play with, as well as more inputs and outputs. A basic wavemorph/wavefold algorithm was the first concept we implemented, and we borrowed the chorus from Virt Iter Legio to put things in the stereo field.

Hard sync and phase modulation are two relatively simple techniques that always yield complex sounds, so we decided to use the other two modes to emphasize these fundamental techniques. Sinc Legio is great as only oscillator in a patch, but it’s equally powerful as an operator in a multi-operator PM array, as a complex oscillator, or as a hard-sync target for other oscillators – or a combination of all three at once!

After some testing and refinement, Sinc Legio was ready to go in record time. The first Legio oscillator took three years to come to fruition, and Sinc Legio took just three days… how the times have changed.

Sinc Iter vs Sinc Legio#

Sinc Legio ended up being quite different from its inspiration, Sinc Iter. While phase modulation, hard sync, wavefolding, and variable waveshapes are a commonality between the two, the final products work (and sound) quite differently. Sinc Iter was designed with some broad utilitarian goals, and as such has a huge frequency range, from single hertz up past the range of human hearing. For ease of use, Sinc Legio stays firmly within the range of musical audio frequencies.

The original Sinc Iter was a single oscillator, and required external modules to perform any sort of phase modulation duties. Sinc Legio has multiple oscillators within its algorithms, so complex timbres can be created without the use of external modulation.

Sinc Iter also had three algorithms: Noise, a variable-frequency noise oscillator; Plain, for basic waveshapes; and Super, similar to Plain with a mono chorus. Sinc Legio also has three algorithms, but all three are based on harmonic sound design, and due to the higher number of parameters on the Legio platform have a broader timbral range. Legio’s chorus can be applied to any algorithm at any time, and in stereo.

If you have an original Sinc Iter in your system, it’s an absolutely fantastic modulation oscillator for PM patches. Try patching both Sincs together and modulate your way across the decades!


We will repair or replace (at our discretion) any product that we manufactured as long as we are in business and are able to get the parts to do so. We aim to support modules that have been discontinued for as long as possible. 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 user modification or other damage are charged at an affordable rate. Customers are responsible for the cost of shipping to Noise Engineering for repair.

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

Please contact us if you think one of your modules needs a repair.

Special thanks#

  • Everyone who wrote in asking about making Sinc Iter again.