Wizardry: Audio Modifiers

Content courtesy of John Papiewski, except where noted

Wave Multipliers (VCM)

Pro: Three different wave shaping sections. I was going to say 'audio wave shaping', but like everything else on the Serge, it can be used for CV also. Top section is a simple linear ac-coupled VCA with switchable mild clipping, handy for modulation or use as spare VCA. Middle section sounds 'something like' a very wild, resonant filter sweep, but that description doesn't do it much justice. Waveform fattener? If you look carefully through the archives on Analogue Heaven you'll find a thorough discussion on what the middle section does, in terms of how the waveform is 'folded over'. The bottom section is very versatile, regular and comparator-driven (pulse wave) outputs deliver woodwind type effects ranging from very subtle to 'bang you on the head.' Electrically, it's a variable full-wave rectifier with level compensation.

Con: Middle section is a *little* noisy. And this is one of a few modules that don't have CV attenuation. In order to make effects more subtle, you sometimes have to attenuate CV in a Processor module or by some other means.

Wizardry: The middle and bottom two sections are most useful with low-harmonic content input waveforms. They have some effect with sawtooth, less with square. This makes sense since they're designed to add harmonics; if the input already has a lot of harmonics the added harmonics stand out less. Since the 2nd input of the middle section is DC coupled, using this with a control voltage along with audio into the 1st input makes for some interesting effects.

The top section is a linear response VCA. Ordinarily this would give dull or unnatural sounding notes when used as a regular VCA, but you can fix this by feeding it exponential envelopes (see notes on DSG and DTG)! Normally, a linear VCA is what you want for amplitude modulating an FM or other exponential parameter.

Triple Waveshaper (TWS)

With the help of Doug Masla and Michael Firman, I've learned a little bit about this one. Yes, it turns a sawtooth into a sine wave, and you can also get hollow buzzy resonant harmonic distortions out of it, similar to Wave Multiplier #3.

From the catalog:
The TRIPLE WAVESHAPER is a nonlinear modifier which can transform a sawtooth wave into a sine wave. This module incorporates three independent waveshapers for modifying synthesizer waveforms or processing signals from preamplified instruments. Although originally designed as a waveshaper for our early oscillators, this module has been found to be an excellent modifier of electronic and acoustic sounds, and is highly recommended for subtle timbral modifications beyond the range of simple oscillator/filter patches.

Tweaks: The "ALL" label on the switch has been relabeled "Series" and "Single" to make more sense. Also, note that if you're flipping the switch to use it in series, the Input is taken in on the bottom waveshaper, and the output is taken out of the top one.

Ring Modulator (RING)

Pro: Same old Serge stuff: versatile, quiet, unique. Two knobs control modulation amount and 'mode': zero through AM through full four-quadrant multiplication.

Con: AC coupled inputs limit its ability to be used as a spare VCA. HOWEVER, see 'wizardry' notes.

Wizardry: Yes, Virginia, you can use this as a VCA, but with the following strange requirement: With your audio going into the Signal In jack only, and mode at Ring, with no voltage going into the VC mode, you will have no output. With increasing NEGATIVE voltage at Mode increases the amplitude of the output, and since Mode is DC coupled, you can put a transient or other envelope voltage here, as long as it's inverted with a Dual Processor or some other way.

Pay attention to where you have the Carrier amount knob set - past twelve 'o clock the circuit is designed to overdrive that input deliberately introducing some clipping and distortion. If you have it fully cranked and get more harmonics than you expected, that's why.

Dual Phaser (2PHA)

Pro: Very nice, creamy-smooth sounding phase shift effects. Multiple simultaneous outputs, phase shift has attenuated VC.

Con: Can it do much besides?

Wizardry: With a small amount of LFO, can do Leslie-speaker type effects.

Frequency Shifters (FRS)

From Chris Whitten:
"A really radical module. Rather expensive although cheaper than the competition (Bode etc.). I feel I've only scratched the surface of this module. I still haven't used the internal (0 and 90 degree) oscillator as I don't yet understand what to do with it. For someone who doesn't understand electronics you can still get some remarkable results just by experimenting with it. Again it's great for processing audio. I've used it for adding strange frequencies to drums and drumloops. Great used on guitar parts. Very expensive but one of the most radical Serge modules."

Wilson Analog Delay (WAD)

From the catalog:
The Wilson Analog Delay was specifically designed to allow internal functions such as filtering, feedback, and delay to be determined by the user as a patch programmable function. Features of the Wilson Analog Delay include the following:
* VOLTAGE VARIABLE DELAY OVER A VERY WIDE RANGE, from a minimum of .0005 sec. to greater than one half second **
* Availability of the TWO DELAYED OUTPUTS (A & B), one which is twice the delay of the other.
* A FLANGING OUTPUT with a control to set its depth
* A 1 VOLT PER OCTAVE (V/OCT) OUTPUT to permit controlling external VC filters easily.
* THREE INPUTS, each with its own gain control and specific function. IN-1 is the main audio input for internal or external signals. IN-2 is suitable for audio, but also for the input of control voltages to be delayed. IN-3 is connected via a switch to provide feedback selectively from either the "A" or "B" delay outputs, or from the AUX jack. This channel features a processing-type control to scale and invert either the feedback from "A" or "B" or the AUX signal.
* An INNOVATIVE NOISE-CANCELLATION CIRCUIT which produces a very clean sound, as opposed to the "muffled" quality of more conventional analog delays.
These features provide an amazingly varied palette of effects. Here are some of the possible ways to use this module:
* "GLIDING" FREQUENCY SHIFT effects (the frequency shift effect is never steady, but is a function of envelopes varying the delay rate).
* STRAIGHT DELAY (perceived as fast repeats as in the delay between two tape recorder heads).
* ECHO CHAMBER EFFECTS, where the delayed signal is fed back into the Analog Delay's input. (The switchable AUX input is particularly valuable for this type effect, especially if an external VCA is inserted into the feedback loop, allowing voltage control of the number of echoes as well as their rate of occurrence).
* DELAY AND ECHO OF CONTROL VOLTAGE ENVELOPES (via IN-2). Though the maximum guaranteed delay is .5 second, in practice the delay will go to more than 5 seconds for low frequency signals such as control voltages.
* MODULATION EFFECTS resulting from the modulation of the input signal by the clock internal to the Analog Delay.

** The first question often asked about the Analog Delay is how long a delay can it do? The answer to this question is fairly complex. Quite a long delay can be performed by the module. However, as delay becomes longer, the bandwidth of the signal which can be processed by the Analog Delay becomes more restricted. As an example, if it is desired to delay a signal consisting of a sine wave at 440 Hz (concert "A"), then better than a half second can be gotten quite cleanly. The same note with a lot of harmonics, say a square wave at 440 Hz, if delayed at a half second, will produce a very modulated output(if the Analog Delay's built-in filters are opened wide) full of extraneous signals, or will lose its overtones because the filters will remove them. (This is why many other delay modules have a dulling effect at long delays). The moral to this story is that one function which the Wilson Analog Delay will not do, is to reproduce the full effects of tape delay (i.e. "echo-plexing") without appreciably changing the signal being delayed. But tape delay is a stock effect, usually available to most synthesists (but which can be used with other voltage-controlled functions such as filtering, phasing, frequency shifting, etc., for more sophisticated effects). The forte of this module is its ability to transform signals and control voltages in an incredible number of ways.

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