Debel Iteritas Alia#

Hybrid additive phase-modulation voice on a swappable oscillator platform


Debel Iteritas Alia is a hybrid additive phase-modulation voice inspired by some of our favorite synth sounds across the decades. Its synthesis algorithms encompass three zesty different takes on four-operator phase modulation, and add in a unique additive edge: each operator contains four oscillators, for completely new and unique synthesis possibilities. There’s a huge number of synth flavors behind the panel, but controlling the relationships of 16 oscillators is easy with Debel’s simple interface and performable controls. Debel’s simple two-parameter envelope covers a huge range of shapes and timing, making it easy to dial in the exact shape you need, too. With CV over every parameter, a dedicated envelope output, and an absolutely massive timbral range, Debel Iteritas Alia is a combo meal of a synth voice in a supremely compact package.

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

  • Type: Hybrid additive PM voice
  • Size: 10HP Eurorack
  • Depth: 1.5 Inches
  • Power: 2x5 Eurorack
  • +12 V: 105 mA
  • -12 V: 10 mA
  • 5 V: 0 mA

Debel - of the bell - from Spanish de "of" + English bell OR from American English - "more life"

Iteritas - repetitiousness - from Latin itero "repeat" with suffix -tas "state of being"

Alia - supreme, from Arabic for "supreme"

"supreme repetition of the sound of the bells bells bells the tintinnabulation of the bells”


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 Debel Iteritas Alia 's interface

Encoder for adjusting pitch. Press and turn for coarse semitone adjustments, or just turn for fine tuning.
The Pitch input is calibrated for 1v/8va tracking.
Adjusts the levels of the additive oscillators, adjusting the weight of the harmonic spectra.
Changes the frequency of the modulating oscillator(s).
Adjusts the amount of modulation between the oscillators.
Adds some saturation and distortion as the parameter is turned up.
Shape and Time
The Shape and Time controls work together to parameterize the attack/decay envelope that controls the dynamics and timbral modulation of the sound. Time controls the overall time of the envelope, and Shape adjusts the ratio of attack vs. decay within that time period.
For example, turning Shape all the way down will create a decay-only envelope, with its length adjusted by the Time parameter. Turning Shape to noon will create an envelope that is roughly equal parts attack and decay, with the overall period of both attack and decay adjusted by Time.
This switch selects which of the three phase-modulation synthesis algorithms are used to create the sound. All algorithms use a unique PM structure: all algorithms use four operators, and each operator in turn has four oscillators that are balanced with the Octave control.
Taco is inspired by one of our favorite presets on a classic FM synth. It uses an identical pair of two-operator PM oscillators, for a 2x2 algorithm with a bright and metallic sound that ranges from soft to crunchy.
Nacho uses a linear four-operator algorithm, where each operator modulates the next in series. Big, crunchy, and tasty sounds galore.
Diablo adds some spice to the sound: it uses the same structure as Nacho, but adds a pitch modulation envelope for big impacts and fiery effects.
Changes the pitch of the voice. Each switch position offsets the pitch by two octaves.
Triggers the envelope. The envelope has no Sustain phase, but any sort of gate or trigger will fire the envelope. Try it at audio rates, too! The Hit button manually activates the envelope.
The audio output of the voice.
Env Out
An envelope output that mimics the envelope shape of Debel’s internal envelope. Spicy routing and patching across your whole system.


The Bell
Set parameters as shown, select Taco mode, and patch in a trigger and pitch sequence. For best results, tune to a mid-range E.
Use Grit to add more flavor to the sound, and change up the brightness of the timbre with Index.

The Debel settings for this patch

Mild to wild
Set parameters as shown, select Nacho mode, and patch in a trigger and pitch sequence.
Use Grit to add some crunch, and Octave to add some additive magic to the sound.

The Debel settings for this patch

Fire and flames
Set parameters as shown, select Diablo mode, and patch in a trigger and pitch sequence.
The Shape and Time parameters have a big effect on the impact and behavior of this sound. Try modulating them by hand or with external CV!

The Debel settings for this patch

Input and output voltages#

Alia’s trigger input has a threshold around +1.8 V.

Its modulation CV inputs have a range of 0 V to +5 V.

Its pitch CV input has a range of -2 V to +5 V.

The envelope output has a range of 0 V to +5 V.

The audio output varies depending on settings, and can reach a maximum of about 14 V peak to peak.


Alia 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.

Design notes#

Note about the design notes: All of this is real and true and taken from the company Slack history.

When we figured out a way to bring the Iteriti back from the dead by putting it on a platform, we knew we wanted to bring something new to the mix too. We’ve been mulling over a variety of synthesis ideas for a while but had no time to develop a new voice module. The platform gave us that chance.

The initial inspiration for Debel was a stock DX7 patch that we all love. We discovered it last year at Synthdaddi, our annual gathering here in Los Angeles where we get together, nerd out, play music, and eat a lot of tacos. Much of what you see is an homage to these roots. We love the patch enough that we tried to get Winterbloom to do a special edition of the Big Honking Button in this vein (we can still hope this will happen, and a taco seedling has been planted). Once we realized we had a platform coming together, though, Stephen sat down at one of our DX7s and started thinking.

Two days later, there was a working prototype. Markus took it and we watched as Slack informed us “Markus is typing” for an exceedingly long time. They had thoughts. We discussed potatoes and lasers.

Stephen and Markus started their banter. For a while no one could keep up (they have been doing this for a while now and they have a sort of language). Shawn saw the concept and joined in (and lobbied hard for lasers but made a great cowbell). Feedback flew furiously in the Slack channel. Firmware versions flew just as fast. Hot sauce was made and eaten. Stephen would optimize one parameter and then another thing would be just slightly out of whack. In the meantime, we ordered the production run of the first batch of Alia, which we had tested the (insert your descriptor of choice) out of using the Basimilus and Manis firmwares.

So of course we immediately found a hardware issue.


It was, thankfully, a very simple one, and a quick value change saved the day (and our butts). Markus and Shawn came over and we swapped things around. Work recommenced. Feedback would come in, Stephen would send out a new firmware. One day, he pushed out 17 new versions. We talked about vegan nacho fries, Mexican pizza, and potatoes (again, but that’s kind of a regular thing here).

“Nature is healing,” said Markus.

We nerded out about the weird world of DX7 controllers and finally, the team gave Kris the go ahead to do her worst and find her release-week show-stopping bug. Friends, she found nothing. It was a Halloween miracle.

Well, no bugs. She did make her office sound like a dungeon and that was fun. Shawn made a very convincing “Secret of My Success.” Markus made pop music. We are full of surprises.

This is all to say that we had way too much fun making this module. It’s been a long year of weird twists and turns so thank you for supporting this merry band of misfits and allowing us to do what we do.


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.