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Preamp Detector (PRNV)
The new Serge preamps and envelope detectors provide an exceptionally responsive link between external audio signals and the Serge synthesizer modules. The key to this responsivity comes from the fact that our detector was designed to respond to the POWER rather than to the AMPLITUDE of a sound. No other synthesizer system offers this sophisticated capability. Human perception of loudness is proportional to the POWER content of a wave, rather than to its AMPLITUDE. Detecting the AMPLITUDE of a signal produces an inaccurate envelope, sometimes too soft, and most of the time too loud. The new Serge detectors are exceptionally accurate, responsive devices which output a control voltage envelope that is directly proportional to the perceived loudness of an input signal. It operates over a very wide dynamic range, in excess of 70 db (or the difference between a whisper and a subway train at 15 feet!). The output is accurately log-linear at 12.5 dB per volt, a taper which mates perfectly with the control characteristics of our newest VCAs. Thus it is possible, for example, to control the loudness of a synthesizer sound by the sound envelope of a locomotive, a dog barking, or a voice going from a whisper to a shout. The effect is especially remarkable [since] because of the accuracy of the responses, the whisper is really a whisper, and the shout a shout.

The PREAMP DETECTOR (PRNV) allies a Serge detector with a multi-purpose preamp suitable for a wide variety of inputs. The HI-Z input accepts transducers such as guitar pick-ups and contact microphones. It is also suited for amplifying low level signals from tape machines, tuners, etc. Detector and Preamp can be switched to work separately or coupled. Sensitivity for the various microphones and audio sources can be adjusted over a very wide range using the Preamp's gain control. Please note that it will not cut the gain to zero, however.

Frequency Shifter (FRS)
The FREQUENCY SHIFTER is an advanced model with several improvements over existing designs:
  • Greatly improved signal-to-noise ratio
  • Extremely high carrier frequency rejection
  • A very clean sound down to very low signal levels (unlike conventional shifters which have increasing distortion at low levels) 
  • No squelch circuit and, therefore, no annoying dropouts or "pumping" action in the sound
These improvements have so improved the quality of the sound, that even the most subtle natural sounds can be processed. Apart from its effect, the FREQUENCY SHIFTER does not intrude with extraneous noises or distortions. The FREQUENCY SHIFTER does not transpose. Rather it shifts each harmonic of the signal by a fixed value equal to the shifting frequency. Thus, as the shifting frequency becomes larger, the relationships between overtones are altered, and timbres change dramatically.

Uses of the FREQUENCY SHIFTER abound. It can be used to frequency modulate natural sounds (from musical instruments, for example), to produce the "Leslie effect" of rotating speakers, and to synthesize other phase shift and vibrato effects. In concert halls, frequency shifters are often Used to control feedback. It performs special effects on human speech, excellent for "computer-like" or "alien-type" speech. One of its most dramatic effects is frequency shifting of an echoed sound, where delayed signals get successively fed back and shifted up or down to produce incredible arpeggios of multiple echoes. Such an effect can be produced with the FREQUENCY SHIFTER and a reverb chamber or tape delay. Quite similar (and other rather far-out) effects can be produced with the use of the Analog Delay module.

...[This] basic unit features a built-in oscillator (with 0 and 90 degree outputs) whose sine wave outputs provide for the smoothest and cleanest shifting... Additional features ... include output VCAs for both the UP and DOWN shifted signals, and an Output providing a COMPRESSED version of the input.

Control Module (C/M)
The CONTROL MODULE (C/M) is provided for economic utilization of extra panel space and as a low-cost source of manual triggers. Also included are two sections for attenuating control voltage or audio signal levels.

Wilson Analog Delay (WAD)
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 **
  • VOLTAGE CONTROLLED PROGRAMMING OF THE FILTERS WHICH CONDITION THE INPUT AND OUTPUT SIGNALS.
  • 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:
  • VC FLANGER
  • "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).
  • CHORUS EFFECTS
  • VIBRATO EFFECTS
  • 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.

Audio Mixer w/ phase switch (3x1) (AMX)
[The Audio Mixer is a three-in/one-out manual mixer with a phase switch on input 3].

Variable Slope VC Filter (VCFS)
The VARIABLE SLOPE VCF (VCFS) offers unique control of sound quality offered by no other synthesizer manufacturer. All VCFs offer voltage control of the cut-off frequency (i.e. control of which frequencies the filter lets pass). The VCFS allows the amount of filtering to be dynamically controlled as well, from barely perceptible filtering to highly resonant, sharp cut-offs. With the variable slope control in the center position, the VCFS acts as a typical flat-response VCF, with high-, low- and band-pass outputs available simultaneously. The slope of the cut-off is 12 db/octave. As the control is moved toward the maximum position, the resonance of the filter increases, so that the cut-off becomes sharper. Although the VCFS will not ring like the VCFQ, it will resonate enough at the maximum setting to pick out harmonics from a complex signal input. As the control is moved to the minimum position, the cut-off slope will decrease to 6 db/octave. This type of change of filter slope has been found to be an effective synthesis technique corresponding well with some of the transformations in acoustic instrument sounds. There are two signal inputs to the VCFS which can be mixed and manually cross-faded from the associated knob.

Resonant Equalizer (EQ)
The RESONANT EQUALIZER (EQ) is a unique ten-band filter designed specifically for electronic sound synthesis and processing. Except for the top and bottom frequency bands, all other bands are spaced at an interval of a major seventh. This non-standard spacing avoids the very common effect of an accentuated resonance in one key, as will be the effect from graphic equalizers with octave or third-octave spacing between bands. Spacing by octaves will reinforce a regular overtone structure for one musical key, thereby producing regularly spaced formants accenting a particular tonality. The Resonant Equalizer's band spacing are much more interesting, producing formant peaks and valleys that are similar to those in acoustic instrument sounds.

There are three equalized outputs, two which mix the alternate filter bands, and one which is a mix of all filter bands. The upper (↑ COMB) lets pass the outputs of frequency bands at 61 Hz, 218 Hz, 777 Hz, 2.8 kHz, and 11 kHz. The lower (↓ COMB) mixes the other bands (29 Hz, 115 Hz, 411 Hz, 1.5 kHz, 5.2 kHz).

This equalizer is different from other equalizers in that the bands can be set to be resonant. When the knobs are in the middle position, the response at the main EQ Output is flat. When the knobs are positioned between the 9 and 3 o'clock position, up to 12 db of boost or cut is set at the band. If the knob is set beyond the 3 o'clock position, the band will become resonant, simulating the natural resonance of acoustic instrument formant structures. Below the 9 o'clock position, increased band rejection is achieved.

Dual Phase Shifter (2PHA)
The VC Phaser (PHA) is perhaps the lowest noise and lowest distortion phase shifter available today. As an aid to recreating some of the subtle properties of phase delay in acoustic sounds, three separate outputs are provided with 360 degree, 720 degree, and 1080 degree of voltage controllable phase shift. A MIX output combines the 1080 degree phase shift with the input signal to produce the multiple notch filter effect that is usually associated with phase shifters. The VC Phaser's log-conforming characteristics and the manual and voltage controls enable ultra-smooth, precisely centered sweeps of phase shift for both spatial effects and timbral modification. For high-density systems. a 2'' DUAL PHASER (2PHA) is available.

Dual Channel Stereo Mixer (2x2) (DCSM)
The DUAL CHANNEL STEREO MIXER (DCSM) is an alternative output VCA/MIXER/PANNER for two and three-panel systems. The other choice for small systems is the UNIVERSAL AUDIO PROCESSOR (UAP). The UAP can be used for a number of voltage controlled mixing functions, but the DUAL CHANNEL STEREO MIXER is used for the standard output level control (or enveloping) and for voltage controlled panning. The DCSM has two independent channels for stereo panning, whereas the UAP can pan only a single channel when used as a stereo panner. Each channel in the DCSM has two VC inputs, one for amplitude control and one for panning. The panning controls are opposite for the two channels, so that if a single control voltage is used, the output signals will pan in opposite directions. Auxiliary inputs are used to mix other signals into the outputs of the module. Signals applied here will not be affected by knobs or control voltages applied to the module. These are mainly useful for linking other mixers (either manual or voltage controlled) to the output bus. The output is available at a pair of banana jacks (for routing the signals to other modules within the synthesizer), and at mini-jacks (for connecting to external amplifiers, tape decks, and other equipment).

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