Ampla Legio#

A multimode filter-gate with a vactrol-inspired envelope.

Overview#

Ampla Legio was the result of our desire for a stereo gate to accommodate the growing number of stereo audio sources in the Eurorack format. With a multimode filter that can be gnarly or nice, a vactrol-inspired envelope, and CV control over filter frequency and envelope timing, Ampla is a simple-yet-effective solution for organic dynamics control.

  • Type: Stereo multimode filter-gate
  • Size: 6 HP
  • Depth: 1.5 inches
  • Power: 2x5 Eurorack
  • +12 V: 140mA
  • -12 V: 22mA

Etymology#

Ampla -- from Latin: "Amplify"

Legio -- from Latin: "versatile"

"Lots of amplification"

Color code#

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

A illustration of two lights. Both are white.

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!

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#

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

The Freq input’s range is -2 V to +5 V. The Hit input responds to a rising edge around +1.6 V.

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

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

Interface#

The Ampla Legio interface

Freq
Sets the starting frequency of the filter .

Note

Press the Freq encoder to manually trigger the envelope generator.

A/D
Sets the ratio of attack versus decay within the envelope time, set with the Time potentiometer.
Time
Sets the overall attack and decay time.
Res: Howl/Bite/Calm
Sets the amount of filter resonance.
Mode: HP/BP/LP
Sets the mode of the filter: highpass, bandpass, or lowpass.
Hit
Gate input for the envelope generator. The envelope generator features a sustain phase and will respond to gate width.

Note

Ampla Legio is an envelope-controlled VCF and VCA. If a gate signal is not present at the Hit input, the module will not pass audio from the input to the output.

In L/R
Audio inputs. The L jack is normaled to the R jack if R is left unpatched.
Out L/R
Audio outputs.

Patch tutorial#

Patch an audio source to In L (and In R if stereo). Patch Out L and Out R to your mixer. Set the A/D and Time parameters to minimum, the left switch to Calm, and the right switch to LP. Patch a trigger or gate sequence to the Hit input. Adjust the Time and ++"Freq parameters to taste for a classic low-pass gate sound.

Try the other Res settings to impart a more aggressive edge to your sound.

Use A/D to change the attack and decay curve of the envelope.

Try all three Mode settings to change the way the timbre of your sound is shaped.

Try multing the 1v/8va signal of your pitch sequence to the Freq input to make the gate open and close to match the frequency of your oscillator.

Firmware swapping#

Use our firmware swap app to change your platform module's firmware at any time.

To get started:

  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 pack of the module, and the other end into your computer.
  4. Follow the instructions in the firmware swap app.

Design notes#

We all love low-pass gates here but have long been put off by the environmental cost of vactrols. Our answer: make our own low-pass gate in software!

Ampla Legio is simple yet powerful. We argued about the featureset, but Stephen put an early version of it in his case and hasn’t taken it out since…so we refined and polished it a bit. If you’ve tried Ampla Versio, the flavor is similar, but no code is shared between them: for Legio, we started from scratch.

Ampla Legio is compact and with fewer controls, a bit more to the point. It’s great for shaping Ataraxic Iteritas Alia if you’re going for a bite, or Cursus Iteritas Alia for a more traditional wavetable, giving a punchy, organic feel.

Warranty#

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#

  • starthief
  • Tim Bartlett