Instruo tanh 3 User manual

tanh[3]
Waveshaper / Limiter
User Manual

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Contents
3
Description / Features
4
Installation / Specifications
5
Overview
6
Inputs / Outputs / Level
7
Patch Examples

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Description
The Instruō tanh[3] is a three channel waveshaper, limiter, overdrive,
and feedback controller.
Each channel of the tanh[3] takes a signal input and outputs the
hyperbolic tangent function (tanh (x)) for that input signal.
... In more musical terms, tangential distortion is a form of soft
clipping which can produce signal amplitude limiting via analogue
waveshaping. Driving a hot audio signal into it will add warm overdrive.
Raw waveforms will be subtly shaped; softening or adding harmonic
content based on input amplitude.
Understanding what the tanh[3] does to a signal, both mathematically
and sonically can be hard to explain, but it essentially adds curves
to signals.
For many Max/MSP and/or PD users, the [tanh~] object may be
familiar and is likely a much used secret weapon in many contexts.
Features
• Waveshaper
• Limiter
• Distortion
• Feedback control
• 3 identical independent channels

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Installation
1. Confirm that the Eurorack synthesizer system is powered off.
2. Locate 4 HP of space in your Eurorack synthesizer case.
3. Connect the 10 pin side of the IDC power cable to the 2x5 pin
header on the back of the module, confirming that the red stripe on
the power cable is connected to -12V.
4. Connect the 16 pin side of the IDC power cable to the 2x8 pin
header on your Eurorack power supply, confirming that the red
stripe on the power cable is connected to -12V.
5. Mount the Instruō tanh[3] in your Eurorack synthesizer case.
6. Power your Eurorack synthesizer system on.
Note:
This module has reverse polarity protection.
Inverted installation of the power cable will not damage the module.
Specifications
• Width: 4 HP
• Depth: 27mm
• +12V: 15mA
• -12V: 10mA

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tanh
[3]
I
O
I
O
I
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tanh[3] | t{nt | noun (mathematics) the hyperbolic tangent of (x);
or as a verb... “a’m gonna tan-h that”
Key
1. Inputs
2. Outputs
3. Level
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1
1
3
3
3
2
2
2

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There are three channels of identical tanh[3] circuits.
Input: Signal input.
• DC coupled input for audio or control voltage signals.
Output: Signal output.
• DC coupled output for audio or control voltage signals.
Level: Input signal level.
• Moving the knob clockwise will increase the amount
of waveshaping.

7
Patch Examples
Waveshaping:
• Patching a triangle waveform through tanh[3] will allow for some
interesting waveshape control.
• When the Level knob is fully anticlockwise, the resulting signal will
be a slightly attenuated triangle wave.
• As the Level is increased, the corners will soften and the waveform
will shape into a sine waveform.
• At higher levels, the sine waveform will soft clip and eventually settle
into a unique pentagon waveform.
Resulting Waveshapes:
Triangle Wave Triangle Wave Triangle Wave
Sawtooth Wave Sawtooth Wave Sawtooth Wave
SineWave SineWave SineWave

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Limiter/Distortion:
• Patching complex audio signals through tanh[3] will result in signal
boosting, limiting, and distortion.
• Sounds such as kick drums, bass patches, and chordal pads work
particularly well.
• The effect is sonically similar to compression but achieved through
waveshaping as opposed to gain reduction.
• Increasing the Level will introduce soft clipping distortion/overdrive.
IN OUT
LIMITING (SATURATION)

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This device meets the requirements of the following standards: EN55032,
EN55103-2, EN61000-3-2, EN61000-3-3, EN62311.
Manual Author: Collin Russell
Manual Design: Dominic D’Sylva
Feedback Control:
• tanh[3] can be inserted in a feedback path to reign in
runaway feedback.
• This concept works in all feedback contexts, including delay loops,
reverbs, filters, and microphones.
• In this context, it functions as a limiter on feedback amplitude.
• In this scenario, there is a much wider range at which a feedback
oscillation will stabilise musically.
DELAY AUDIO
OUTPUT
AUDIO
INPUT
FEEDBACK CONTROL