Sinc Iter#

Twenty-three octave multi-mode voltage-controlled oscillator


Sinc Iter is a 4HP voltage-controlled oscillator with a 23 octave range. It has three waveform modes: Noise, Plain, and Super, each of which allow continual morphing between waveforms. Front-panel unipolar and bipolar outputs allow for easy use as a control source. Phase modulation and sync modulation are both supported to provide maximal tonal variety. The Sinc Iter also has a built-in quantizer.

  • Type: VCO
  • Size: 4HP Eurorack
  • Depth: 1.5 inch
  • Power: 2x8 Eurorack
  • +12 V: 150 mA (80 mA when using 5 V supply)
  • -12 V: 10 mA
  • +5 V: 90 mA


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 Sinc Iter's interface

An encoder used to select the base pitch of the oscillator. Tapping the Pitch knob toggles between coarse (red LED) and fine (green LED) mode. Pressing and holding Pitch for two seconds will toggle the pitch-based amplitude compensation. All settings are stored in flash and will persist through power cycling. The base pitch can be varied across 23 octaves of range ("lower than you care about to higher than you care about").
Selects the algorithm used to produce the waveforms. Plain is a variable sample rate direct waveform synthesis. Mathematically it is equivalent to a wavetable, but the table is computed on the fly. Super mode is 6 oscillators with LFO phase modulation. Noise is a fixed sample rate Perlin noise oscillator.
Controls the timbre of the waveform. In Plain and Super modes, it morphs through the basic waveforms (sine, square, saw, triangle, sine) then starts wavefolding the sine waveform. In Noise mode, it broadens the spectrum and then begins wavefolding.
Is the CV input for Morph/Fold. It sums with the position of the knob.
Controls the built in quantizer on the 1V/8VA input. 00 is disabled, 24 is quarter tone (24-tet) and 12 is semitone (12-tet).
Is a hard sync input for LFO sync and sync modulation. This is a rising-edge triggered input.
is a standard 1 V per octave pitch input. It has eight octaves of range.
is a DC-coupled bipolar phase-modulation input.
is a DC-coupled unipolar output 0 V to 5 V.
is a DC-coupled bipolar output -5 V to 5 V.

Patch tutorial#

Sinc Iter is an oscillator. The easiest place to start is listening to the output directly. Connect the Bi jack to your monitoring system. Turn the Pitch knob to adjust the pitch. Tap the Pitch knob to change between coarse and fine adjustment. Select between the three modes with the Noise/Plain/Super switch. Turn the Morph/Fold knob to adjust the timbre of the sound.

Voltage select#

Sinc Iter can run its processor on the 5 volt eurorack power rail to reduce noise and load on the 12 volt bus. Gently push the switch tab in the direction of the desired rail to use.

Picture of voltage supply switch


The Sinc Iter comes calibrated and should not need adjustment. On the off chance the trim pot gets bumped and needs a tuneup, follow this procedure to calibrate your module.

Pitch calibration is controlled by an linear resistor-divider network. To calibrate the tuning, attach a voltmeter (preferably 4+ digit) to the test points TPCV and TPGND on the rear panel and adjust the trim pot.

The voltage measured should be 5/16 (.3125) times the input voltage applied to the CV input. A reasonable way to tune the scale is to use an adjustable voltage source to generate 4 V then adjust the tuning trim until the test points read 1.2500 V. Sinc Iter can also be tuned using a reference supply capable of generating a 1 V difference and using a stroboscope such as the Peterson 490 to tune to an octave interval. This is method is preferred to the meter-only method.

Design notes#

Sinc Iter came from a simple desire to have a stable wide-range oscillator in 4HP. As many features as possible were crammed into the space to try to maximize utility.


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#

  • Kris Kaiser
  • Aaron Funk
  • Shawn Jimmerson
  • Skyler "kittyspit" King
  • William Mathewson
  • Mickey Bakas
  • Tyler Thompson
  • Alex Anderson