Viol Ruina#

Resonant lowpass filter and distortion with internal modulation and envelope following


Viol Ruina is an all-analog distortion and lowpass filter with an internal envelope follower and self-modulating cutoff. The four-pole design is reminiscent of the classic filters we all know but with a completely new and slightly ridiculous twist. The independently addressable distortion circuit takes Viol Ruina into overdriven paradise with a shocking amount of drive. Built-in envelope following makes an easy way to create dynamic patches with the flick of a switch, and feedback FM takes Viol Ruina to a whole new realm of filthiness. Run a sound through Viol Ruina, you'll get something cool out of it.

  • Type: Distortion/filter
  • Size: 4HP Eurorack
  • Depth: 0.8 inch
  • Power: 2x5 Eurorack
  • +12 V: 40 mA
  • -12 V: 35 mA


Viol -- from Latin violo, violentis: "violate, dishonor, violent" Also viola, "purple"

Ruina -- from Latin: "Destruction"

"Violent purple ruins"


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.


Illustration of Viol Ruina's interface

Filter cutoff frequency. Knob sums with the Frq CV input.
Engages the internal envelope follower at different amounts, routed to the cutoff frequency. Down position is off, middle is mild, high is extreme.
Filter resonance.
The audio is routed back to the filter cutoff frequency for input-dependent FM. Down position is off, middle is mild, high is extreme.
Distortion amount. Enough said.
Frq CV
CV input for filter cutoff frequency. Responds to 0 V to 5 V.
Filter In
Audio input to the filter section.
Filter Out
Audio output from the filter. Normaled to Mangle In; normal is broken when Mangle In is patched.
Mangle In
Audio input to the distortion section.
Mangle Out
Audio output from the distortion section.

Patch tutorial#

Patch 1
Patch a simple waveform like a saw wave to the Filter In jack. Patch the Mangle Out jack to your mixer. Play with the Frq, Q, Mod, and Mangle parameters to hear what it can do.
Patch 2
Patch a signal with lots of dynamics and harmonic content like a drum loop into the Filter In jack. Engage the Laser section and hear how the envelope follower shapes the filter to the sound.
Patch 3
Patch a sound to Mangle In. Patch Mangle Out to Filter In, and Filter Out to your mixer. Now you can distort your sound before the filter! Cool!

Design notes#

Viol Ruina came into existence as part of the Distortion of the Month series. It all began with a single epic distortion module that was really more of an experiment many years before. That module had something like six distortions on it and was really an experiment meant to get a feel for each individual one. Like so many of our early ideas, we knew we had something, but we just didn't have time to get to it. It sat.

When we hired Markus, we dusted it off and handed it to him. He came back to work next all starry eyed and we were convinced that now was the time to do something... but what exactly we weren't sure. We told Markus to go home and decide which of the circuits he liked and how and why. When we sat down to discuss, we designed a load of distortion modules, including Viol Ruina. It took a little more work and redesigning to get it to its current state -- the envelope extraction was a great add, and we finally had a gasp filter!

It sounded darker and meaner and awesomer than we could have hoped for. Viol Ruina We're sorry. You're welcome.


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.