Random*Source JHaible VC POLY RESONATOR User manual

JHAIBLE
VC POLY
RESONATOR
FOR EURORACK
USER MANUAL
V1.0
RANDOM*SOURCE

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VC POLY RESONATOR
Installation ........................................................ 3
Overview ......................................................... 3
What’s new? What’s different? ......................................... 3
VC Resonator - Basic Operation........................................ 4
Input (#1) and Gain (#10) ............................................. 4
Outputs LOW, BAND and HIGH (#2, #3, #4)............................... 5
DRY (#6).......................................................... 5
FREQUENCY (#9)................................................... 5
VC CONTROL OF FREQUENCY (#7, #8) ................................. 5
VC Resonator - Patch Ideas ........................................... 6
(Version 10 March 2023).............................................. 6

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VC POLY RESONATOR
Installation
Always turn the eurorack case off and unplug the power cord before plugging or unplugging any eurorack power
cable. Do not touch any electrical terminals when attaching any eurorack power (bus board) cables.
The Haible Resonator is an electronic music module requiring 50mA of +12VDC and 50 mA of -12VDC regulated
voltages and an appropriate power connector to operate. It must be properly installed into a eurorack format
modular synthesizer system case.
POWER YOUR CASE OFF before installing the module. Please use the power cable provided to connect the small
end of the power cable to the module: RED STRIPE to “-12V”, as indicated on the back of the module. Carefully
install and secure the module in your case. Power on and your module should be ready to go :-)
Please beware: Powering the module on anything more (or less) than +/-12V is not recommended and may
damage the module. Feeding any of the inputs (or outputs) with voltages outside a +/-12V range may damage the
module. This type of damage is not covered under warranty.
Overview
The Haible VC Resonator is an evolution of Jürgen Haible’s Resonator which was inspired by the Polymoog
Resonator. As Jürgen stated: “The Polymoog, an early polyphonic synthesizer, featured a 3-band “Resonator”
section that allows Formant-Filtering in addition to its dynamic Filters. Such a Resonator is a very useful
feature for analogue synthesizers”. Each of the three lter channels has a control for frequency, signal gain, and
emphasis (resonance).
What’s new? What’s different?
As its predecessor, the core of the module comprises 3 lter bands - LOW, MED(IUM) and HIGH. In the previous
version(s), the center frequency of each band could be set with a knob within a certain (limited) range. The VC
Resonator now not only adds VC control for each band, but also extends the ranges whithin which each
frequency band can be set - adjacent bands can now overlap or even cross over, for instance the LOW and
MED bands can now be set (or moved!) so that the LOW center frequency is higher than the MED frequency.
Jürgen’s original Resonator (like the Polymoog) had a switch to select one of 3 basic modes, i.e. only one mode
could be used at a time. The Haible VC Resonator now provids the same 3 modes as separate outputs so they
can be used simultanously, e.g. for further processing like crossfading.

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VC Resonator - Basic Operation
Send a audio signal into the IN (#1), make sure all three GAIN knobs (#10) (or at least one) are not set fully CCW
and listen to either output (#2, #3 or #4). The DRY knob (#6) determines how much of the (dry) input signal is
added to the processed signal, i.e. it is not a WET / DRY mix but rather a +DRY. Play with the Frequency knobs
(#9), GAIN (#10) and EMPHASIS (#10) to shape the sound.
VC POLY RESONATOR
GAIN
EMPH
LOW
GAIN
EMPH
MED
GAIN
EMPH
HIGH
HAIBLE
IN
DRY
LOW
HIGH
BAND
MODE
7 3x
CV INPUTS
8 3x
CV ATTENUVERTERS
9 3x
BAND FREQUENCY
10 3x
INPUT ATTENUATION
11 3x
RESONANCE (Q)
2
LOW OUT
1
INPUT
6
ADD DRY
3
BAND OUT
4
HIGH OUT
5
MODE SW
LOW BAND MED BAND HIGH BAND
Input (#1) and Gain (#10)
Each GAIN knob (#10) determines how much of the input signal present at IN (#1) is actually sent into each lter
band. The GAIN knobs act as attenuators. When all three GAIN knobs are set to minimum (CCW), the three lters
do not receive any input signal, i.e. the 3 knobs act like a single attenuator at the input jack. Turning down GAIN,
however, has also the effect of giving more weight to resonance (EMPHASIS, #11) especially when EMPHASIS is
so high that it self-oscillates.

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Outputs LOW, BAND and HIGH (#2, #3, #4)
LOW and HIGH provide a combination of the three LOW and HIGH outputs of each lter band. Of course, if
the GAIN of any band is turned down completely (and EMPHASIS also), a band may not be present at all. The
BAND output has a MODE switch (#5) that allows you to select whether the MED band is actually added to or
subtracted from the other two frequency bands, providing an additional Band pass “notch”mode. Depending on
the input signal and module settings, this has a more or less noticeable effect.
DRY (#6)
The DRY knob (#6) determines how much of the (dry) input signal is added to the processed signal, i.e. it is
not a WET / DRY mix but rather a +DRY. As this can lead to phase cancellations, the DRY knob can have quite
interesting sound shaping effects.
FREQUENCY (#9)
The Frequency knobs sets the center frequency of each lter band. These bands are not identical, but spaced out
to cover (and exceed) the classic LOW, MED and HIGH ranges of the original Polymoog - that means each band
is limited to a certain frequency window. The adjacent windows, however, overlap, so that the LOW frequency
(turned up) can be higher that the MED frequency turned all the way down.
VC CONTROL OF FREQUENCY (#7, #8)
The frequencies of he three lter bands can also be voltage-controlled using three attenuverters. Turning the
attenuverter right (“black swoosh” area) means a positive control voltage (CV) applied will have a positive (=
increasing) effect on the frequency set by the knob (#9). When the attenuverter is turned left (“empty swoosh”),
such CV will push the frequency down. While the VC control is primarily intended for control voltages - e.g. using
a sequencer / programmer to step between different settings - interesting results can also be found by sending
clicks or audio signals (e.g. feedback) into the VC inputs.

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VC Resonator - Patch Ideas
Basic Pinging - using the Resonator as a sound source
Letting the Resonator resonate on a Using both sides combined as one tracking oscillator.
• Feed a click signal into the IN, e.g. a single spike (sawtooth form from a DSG) or a pulse (that will gener-
ate 2 clicks, one on each ank).
• Set the Frequency knob of each band to minimum (CCW).
• Set GAIN to about 50% and EMPH to maximum (or almost maximum).
• Use a Sequencer to control the CV inputs of each band, i.e. to step through different settings.
• Listen to any output and play with GAIN and EMPH to explore.
• Changing the input shape (rising edge) of the click slightly will have an effect, also dialing DRY in.
Abusive Pinging
Starting from the patch above, try swapping the input signals (click from DSG and sequencer outputs), like
• Send the click into a CV in rather than the IN.
• Try patching any output to any CV IN and play with the attenuator.
• Use one of the CV signals from the sequencer as input (this will again just use the steps as a click).
(Version 19.04.23)
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