Ovis Legio#

Granular pitch shifter stacking and crossfading octave-spaced layers for gliding Shepard tones

Overview#

Experimental granular and Shepard-tone processor for

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

Etymology#

Ovis -- from Latin: “Sheep”

Legio -- from Latin: “legion, army”

“Army of Sheep”

Color code#

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

Power#

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#

Pitch (encoder+CV input)

Octave phase of the endless sweep, which wraps every octave. To achieve continuous pitch sweeps, patch an LFO to the CV input.

Count (potentiometer+CV input)

Sets the number of grains from 0 to 16.

Length (potentiometer+CV input)

Sets the grain's window size.

Fade (switch)

Sets the type of grain crossfading, with more random results in the higher positions.

Layers

Sets the number of octave-spaced layers: 2, 3, or 4.

Hit

Freezes all layers when a high gate is applied here.

In L/In R

Audio input. The L jack is normaled to the R jack if R is left unpatched.

Out L/Out R

Audio outputs.

Patch tutorial#

Patch a freerunning oscillator to the audio input(s), and an LFO to the Pitch input.

Use an attenuator to constrain the range of the LFO to dial in how dramatic the Shepard tones are.

Adjust Length, Count, Fade, and Layers to taste: static waveforms often perform well with long layers and high counts, and more experimental inputs, like samples and drum loops, can sound more interesting with lower values.

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#

Ovis Legio came from Patrick's request for a Shepard-tone processor. Shepard tones are an aural illusion that sound as if their pitch is continuously rising or falling. Ovis allows this effect to be arbitrarily applied to any signal, while simultaneously being an experimental granular processor for more out-there patches. Once it was finished, we had a lot of internal arguments about it, but we asked our really great group of beta testers what they thought and it was resounding approval. Ovis made the cut.

Special thanks#

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

No farm animals were harmed in the making of these firmwares.