The Fader/EnvFollower/Shaper

The Fader/EnvFollower/Shaper is special because it includes upgrades/redesigns of existing modules but also a new function. It comes in a panel with the Rungler, the Phaser and the FrqShifter. The Rungler may be switched to another module depending of one needs.

The DualFader now comes as a single Fader.
It has 2 knobs : Fade position and Fade modulation. It still has the same 5 connectors for different patching options. More on that later.
Please read the DualFader article to know more about it if you'd like.

It now has 2 switches.

The first switch gives the choice between RMS and linear curve behaviour.
The RMS curve will give an equal loudness contour no matter the fader position or modulation. It is better in use for audio purposes.
For processing CV signals (remember that all inputs and outputs are DC-coupled in Rob's modules) the linear curve might be a best use.
In the middle position of the Fader the linear curve gives -6dB of attenuation while the RMS mode gives -3dB.

The second switch is labelled Normal/Ringmod and affects the addition from the right output connector to the left output connector.
If only the left input is used the input signal is normalized to both VCAs. If only the left output is used then the right output signal is normalized to be added to the left output. In this case there is always an output signal no matter how you set the position knob. But if the right output signal is inverted (which this switch does) then the signal cancels out in the middle position of the knob. In this case modulating the position means that one get ringmodulation of the signal on left input with the signal on the modulation input and the left output connector will be the ringmodulation output.
If one would use a second input signal on the right input connector then one would crossfade, but the right input signal would be inverted if the switch is in RM mode and not inverted if its in Normal mode. This can be useful when crossfading between two modulation signals. It can also be used to e.g. fade between a positive envelope and the inverted envelope under voltage control. This is actually the main reason why the mode is there, to be able to invert a CV signal in a crossfade mix. But the moment one plug a jack in the right output connector the switch doesn’t do anything anymore, as it takes its signal from the normalization pin on the right output connector. So, it only works in cases where the right output connector has no jack connected.
Compared to the bipolar VCAs the RM mode on the Fader is slightly less perfect. It is possible to completely suppress the left input signal, but due to some inherent but quite low harmonic distortion in the VCAs the fundamental of the modulation signal on the modulation input can be suppressed but some of its harmonics will be faintly heard. In this respect it is very much a faithful replication of an old ringmodulator with a faint carrier leakage.

Depending of the jack patching, the Fader can have the following functions:
- For panning, use input 1 / output 1 and 2.
- For crossfading, use input 1 and 2 / output 1.
- For ducking, use input 1 and 2 / output 1 and 2.
- For ringmodulation, use input 1 / output 1. Mod input is the second signal and the second switch needs to be set to RM mode. First switch makes no difference.
- As a single VCA, use input 2 / output 2. Mod input is level CV, the RMS switch sets the curve (linear or 'anti-log' when in the RMS mode -more or less the 'opposite' of an exponential curve).


The envelope follower is a feature that I was missing in Rob's modular and I am very glad it finally is here.

The EnvFollower has a signal input, an envelope CV output and a trigger output. One knob will set the input gain and a second knob will set the trigger threshold sensitivity. Next to the peak LED is a LED to signal a trigger.

The EnvFollower has a high input impedance preamp that can boost the input between unity gain and a gain of about 40x. This is enough to e.g. connect a dynamic mic, an electric guitar, laptop signals, mpeg , etc...
The EnvFollower preamp output is internally normalized to the Shaper, the Phaser and the FrqShifter inputs. As the Shaper and Phaser inputs have a dry/wet knob one can use the dry preamp signal from either the Shaper or Phaser output.

The EnvFollower is quite fast on attacks and has an extra trigger output when it detects a change from a downslope to an upslope. Normally envelope followers are quite slow, as they need a smoothing filter at a very low frequency to filter the audio from the CV signal. This gives a sluggish behaviour. Rob designed a special smoothing filter that has a much higher cutoff when the slope goes up and a normal slow filtering when the slope goes down.
The EnvFollower is a chain of a preamp, a peakdetector with the specially adapted smoothing filter, plus an up/down slope detector to signal a transient signal in the incoming audio.
The result is that it follows percussive sounds much better and creates a trigger on the instant when a percussive sound is hit. So, if one would feed it a drum computer signal with kicks, snares, hi-hats, etc., it is able to instantly give a trigger on any hit.

The envelope CV output can modulate e.g. the Phaser or the FrqShifter and turn the panel into a ‘whammy’.
The trigger output can be used to clock the Rungler, DualEnv, sequencers, etc.


The Shaper is a different design. It uses four knobs, but only two connectors. So, the VCA/Ringmod will be dropped. As that VCA is exactly the same as the two bipolar VCAs on the NodeProcs its not really an issue.

The original one was a bit noisy due to some complex diode issue involving natural quantum noise in diodes. Rob redesigned the wavefolding part forcing all the diodes in a working mode where they do not produce that much quantum noise. In essence it does the same kind of wavefolding, but the symmetry knob from the original design has been replaced in favour of a symmetry knob like is on the old Blender module. It makes it sound cleaner, smoother. But the frequency doubling effect of the previous Shaper is gone.

The Depth knob sets the amount of wavefolds. The Symmetry knob will introduce even harmonics to the odd harmonic distortion produced when folding a symmetrical waveform like a sinewave.
The Overdrive knob will introduce a mild overdrive effect by 'tilting' the momentary angle of a folded waveform and theMix simply fades between the dry input signal and the wet folded signal.

Here is the flowchart if the Fader and EnvFollower :

Here is the flowchart if the Shaper :

Check these videos for sounds and more explanations :

The ShaperPhaser

The waveshaper is a 'wavefolder'-type waveshaper, that in its simplest form with a pure sinewave as input creates a odd harmonics spectrum similar to 'through zero'-type linear FM modulation, but always follows the input pitch exactly and can never go out of tune, also the waveform will always stay the same. In essence it is comparable with a wavetable containing multiple cycles of a sinewave and where the input signal is used as an 'index' to read values around the centerpoint of the table. But as this is a pure analog module an array of diodes and opamps is used to 'create' the table. The carrier signal is 0Hz so it is not present.

The input is a bipolar VCA. The modulation depth depends on the level of the input signal. This can be controlled by the bipolar VCA or when the SHAPER IN input receives a signal directly from a OscHRM VCA OUT it can be set by the VCA in the oscillator.

The bipolar VCA can also double as a ringmodulator when controlled by a bipolar CV signal, no matter when at LFO or at audio rate. If no signal is connected to the VCA MOD CV input then it fades between no signal and full level. The VCA MOD control knob fades between an input signal in the leftmost position to an unmodulated full output level in the rightmost position.

The output connector of the VCA is normalized to the input of the waveshaper, so if the waveshaper input is not connected it will get its input signal from the output of the VCA. This normalization allows the VCA to be used separately from the waveshaper or as the input level control for the waveshaper.

The SYMM knob is sort of a pre-shaper that will add even harmonics when a sinewave is used as input. It makes the input assymetric. Fully opened, this double sthe pitch which creates the second harmonic.

The OD knob adds overdrive distortion to the waveshaped sound, adding fuzzy sounding high harmonics to the sound, but it does not alter the modulation depth.

You can create very complex spectra when using the the VCA as ringmodulator on the input of the waveshaper with its pre-distort and fuzz options...

The switch routes to the left side of the MIX knob.

In its top position it receives the input signal to the VCA and the MIX knob crossfades between the VCA input and the shaper output. Used this way one can fade between an unaltered input signal and the waveshaped signal where the waveshaping depth is set by the VCA MOD knob and can be modulated by a CV signal on the VCA MOD CV input. One would normally want to route the output to the Filter/VCA module.

In the middle position the switch is off and the MIX acts like an output level control. One would have the switch in this position when using the VCA and waveshaper separately.

In the bottom position the MIX knob leftmost position gets its signal from the waveshaper input and this would be a dry/wet type of efx-mix. One would use this mode e.g. when the VCA and waveshaper are used independently and one would like to have a dry-wet mix control for the waveshaper only, or optionally when the bipolar VCA would be used as an enveloped VCA.

Here is the flowchart of the Shaper :

I was not able to upload the video of the Shaper at Novars Masterclass as I cannot compress it under 100Mo so here is the link : https://vimeo.com/240798045. It includes technical information on how it was designed. Very interesting video.

For the Phaser I will only talk about a single Phaser, the DualPhaser is basically 2 Phasers with internal normalization for the inputs and outputs. If you really want to know more about it please let me know.

The Phaser a 8-stage phaser. It has a reasonably accurate 1V/Oct direct control input that can track the keyboard voltage.

Total control range is about 18 octaves. The Freq knob goes over the top 9 octaves of this range. Through the V/Oct and Modulation inputs you can go deeper, but you get into the LFO range and audible phasing effects would disappear.

It is however possible to use the phasing effect on LFO control signals in the 1Hz to 10Hz range by supplying the V/Oct with e.g. a fixed -5V control signal, which can create quite interesting LFO effects on e.g. drones. All inputs and outputs are DC coupled. Only the internal resonance is AC coupled, so resonance drops off below roughly 10Hz.

Additionally the phaser has a modulation input, also at 1V/Oct when the mode is set to sweep. The input is not normalized, in fact if no plug is connected the modulation level knobs receive a fixed voltage so a manual spread value can be set.

Audio input is maximum 12V peak/peak before clipping occurs and there is 6dB attenuation from input to output to enable resonance peaks without clipping. The Phaser can act as a distortion device, where you modulate the cutoff with the audio input.

The MOD input has three functions, determined by a three position toggle switch:
1. SWEEP MODE - Standard frequency sweep, like other phasers, where all peaks sweep up & down as a group.
2. SPREAD MODE - The upper peaks and the lower peaks are spread apart & pulled closer together and cross over each other. This produces vocal timbres/formants and all sorts of complex filter effects and sounds really wonderful.
3. HALF-SPREAD MODE - the upper peaks move further away & closer to the lower peaks and the lower peaks are not affected.

The MIX control is bi-polar which adds even more sonic possibilities. Set straight up at 12 O'Clock you get dry only, no phaser (bypass mode). Turn it clockwise and you increase the phaser mix, and the phased output is positive. The original signal is still present. Turn it counter-clockwise and you increase the phaser mix, but now the phased signal is inverted which sounds very different from positive phasing. The original signal is not present. It then may sounds a bit less louder at higher resonance settings.

The resonance control always provides positive (non-inverted) feedback, regardless if the mix control is set to positive or negative. If the resonance is fully turned, it can produce very nice percussive effects (pings).

There is no flowchart for the Phaser as it is basic and obvious.

Here is a video of the Phaser with great sounds and tips :

Thanks to Todd Barton for providing the picture of the module.

Modular Meets Leeds synth tutorial

In this video, Rob is showing a great use of the Shaper module. One can create a totally complex sequence using a waveshaper.

And it is also nice to have more modules explanation.