Fala Versio#

Stereo formant filter with wavefolding, saturation, and a tap-tempo LFO

Overview#

Fala Versio is a stereo formant filter designed with pure musicality in mind. Fala has a selectable set of 1, 2, or 3 resonant filters, with a built-in clockable stereo LFO to bring some panning animation into your patches. Fala also features an input wavefolder, perfect for adding grime to harmonically simple signals pre-filter, and a saturator on the output to really make things scream. Whether you want resonant, vocal tones or uniquely modulated filth, Fala Versio is the perfect tool to take your patches to new timbral spaces.

• Type: Stereo formant filter
• Size: 10 HP
• Depth: 1.5 Inches

Power#

To power your Versio, 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.

If your Versio looks like the left picture, it requires 70mA +12v and 70mA -12v. If it looks like the right picture, it requires 125mA +12v and 10mA -12v. Versio does not use the +5v rail.

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

Etymology#

Fala – from Portugese: “speak”

Versio - from Latin: "versatile"

"Spoken Versatility"

Color code#

On boot, the Versio's LEDs will shine with this color pattern to indicate that it is running the current Fala Versio 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!

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#

All CV inputs expect 0 V to 5 V.

Interface#

Fold

Sets the amount of pre-filter wavefolding.

Q

Sets the resonance amount of all three filters.

A2-A5

Sets the frequency of the first filter, from A2(110hz) to A5(880hz).

E4-E7

Sets the frequency of the second filter, from E4(330hz) to E7(2637hz).

Speed

Sets the rate of the internal LFO. If using an external clock or a tapped tempo, this parameter acts as a divider/multiplier, with the following settings: /4, /3, /2, 1, x2, x3, x4.

Index

Sets the amount of stereo LFO modulation applied to the filters. The LFO is off at noon, sinusoidal to the right, and random to the left.

Saturate

Increases the amount of post-filter saturation.

A/AE/AE3

Sets the number of active filters. In the left position, only the A2-A5 filter is active. In the center position, A2-A5 and E4-E7 are active. In the right position, a third filter is added based on the positions of A2-A5 and E4-E7.

I/II/IV

Sets the number of parallel filters to one, two, or four, creating a chorus-like effect.

Tap

Tap tempo control/clock input for the LFO. To clear a tapped tempo and return to a freerunning internal LFO, hold the Tap button for a few seconds.

Patch tutorial#

To start, set Fold and Saturate to minimum, Index to noon, and the top switch to the middle AE position. Patch a harmonically complex waveform like a saw to the L input, and the L and R outputs to your mixer. Adjust the A2-A5, E4-E7, and Q parameters to filter your sound.

Turn Index up and adjust the rate of modulation with the Speed parameter, or tap in a tempo with the Tap button.

Experiment with different switch settings, and turn up Fold and Saturate to add some grime to your sound.

Try a variety of sounds at the input: everything from basic waveforms to drum loops and stabs are fabulous filter fodder for Fala.

If you’re using a rhythmic sound source like a drum loop, try patching a copy of your clock signal or a trigger pattern to the Tap input to sync the internal LFO to the rest of your patch.

Starthief’s feedback stereo patch: Try patching a mono source to the L input, mult L output to the R input, and monitor both the L and R outputs for some extra feedback and texture.

Signal flow#

Before formant filtering is applied, a signal at the input is processed by a number of utilities. Fala features many stages of distortion processing, so a noise gate is applied to help keep the noise floor low at the output. After this, three allpass filters are applied to the signal, allowing the wavefolder to have a musical effect on nearly any input signal. After the allpass filters, soft clipping keeps levels in check, and then wavefolding can be applied with the Fold parameter.

After the input chain, the signal is processed by one, two, or four sets of formant filters, selected with the I/II/IV switch. After filtering, the signal is treated with a volume compensation stage, effectively a software-controlled VCA, that keeps levels in check based on the position of all filter parameters. Limiting and soft clipping are applied after the volume compensation stage to further normalize and color the signal.

Each formant in the graph above is comprised of a 2x3 grid of bandpass filters, each followed by an independent saturator. Formant A is controled by the A2-A4, formant E is controled by the E4-E7 parameter, and formant 3's frequencies are set based on formant 1 and 2's settings. The A/AE/AE3 switch selects whether formant A, formants A and E, or formants A, E, and 3 are active respectively.

The Q parameter affects the resonance of all bandpass filters simultaneously, and the Sat parameter adjusts the level of all saturators. With the switches in the IV and AE3 positions, a total of 24 bandpass filters and 12 saturators are used simultaneously!

Design notes#

This firmware has been kicking around NE for quite a while – some sort of formant filter has been on our idea list since the very early days. We’ve developed a lot of different versions of filters for our digital products over the years, so throwing a proof-of-concept formant filter ended up being a first firmware project for Adam, one of our engineers. The initial design concept was a pretty standard formant filter that allowed the user to drive the formants around the vowel space. This space is a funny shape, an irregular quadrilateral, and we had a lot of problems making the parameterization feel musically useful.

Adam settled on the most musical control set possible: the final parameterization keeps the two formant frequencies independent, and the ranges of each are based on musical notes rather than the normal human formant frequencies. We rounded out from the normal human formant frequencies onto notes so that each knob could be a range in whole octaves, and allowed formants to be turned off via a switch.

There are a bunch of vocal filter projects discussed in Electronotes and we took the cue for our LFO modulation from VEWA (EN#102). VEWA was a multi-part effect but it was built to have filters in the formant range with a bunch of LFO modulation options. The LFO on Fala ended up being pretty simple with a smooth noise or sinusoidal LFO, similar to LFOs we have used on other modules.

To make the LFO more fun, we added more filters in parallel. In total, Fala has 12 second-order filters in groups of 3 formant frequencies and 4 parallel formant sets. The filters are built out of a pretty basic trapezoidal-integrated state-variable filter with some nonlinearity added for fun and harmonics. When the additional formant sets are added, the LFOs modulate them using different LFOs: for sine they are the same frequency but different phase and for noise they are similar in frequency and independently random.

Of course, a Noise Engineering filter wouldn’t be complete without fold and saturation. They’re standards that always work great with filters.

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#

• Adam Lange-Pearson
• ElectroNotes
• starthief
• Tim Bartlett