Features and Notes
New Timbral Oscillator (NTO)
The Serge Modular Systems NEW TIMBRAL OSCILLATOR (NTO) is the state-of--the-art VCO, featuring exceptional range, superb temperature stability, and accurate tracking. Dynamic depth frequency modulation and voltage control of waveform allow unprecedented control over a wide range of sound qualities.
- EXPONENTIAL 1 VOLT/OCTAVE RESPONSE
Exponential response parallels the response of human hearing perception as well as musical pitch structure. With multiple oscillators, each must respond exponentially to control voltages to allow transposition from key to key and to produce alternative equal-tempered tunings such as quarter and third tones. In addition, the one-volt-per-octave response assures that the New Timbral Oscillator is compatible with most keyboard and computer controllers.
- ACCURATE TRACKING
When two or more oscillators are tuned, it is expected that they will remain in tune throughout their entire range (in other words, that they track). Even two oscillators which track within a fraction of a semitone will be out of tune at the extremities of their range. Therefore, the New Timbral Oscillators have been designed so that any two will track within one cycle/second throughout their entire musical range.
- TEMPERATURE STABILITY
Instability of pitch with changes in temperature is the criticism of most synthesizer VCO's. Performers are aware of the disastrous effects of temperature when they must desperately retune oscillators that have drifted during a live performance. The temperature sensitive components are kept at an even 120 degrees by a solid-state "oven". Thus temperature stability is guaranteed from 50 degrees to 100 degrees F.
- WIDE FREQUENCY RANGE
The frequency range covers from below 16 to 16Khz. With control voltages, the range can be further extended from less than .1 Hz (10 sec/cycle) to greater than 100,000 Hz.
- VARIETY OF WAVEFORM OUTPUTS
In addition to three standard waveforms (sine, triangle and sawtooth) of exceptional purity, the New Timbral Oscillator offers a variable waveform output providing an amazingly varied range of sounds, unavailable on any other synthesizer. This waveform is voltage controllable, allowing dynamic control of sound quality.
- DYNAMIC DEPTH LINEAR FREQUENCY MODULATION
Dynamic depth frequency modulation is now available to the analog synthesist. Frequency modulation (FM), the modulation of one oscillator by another, generates both harmonic overtones (found in most acoustic instrument sounds) and non-harmonic overtones (bells, percussive, and electronic timbres). By varying the amplitude of the modulating oscillator, the richness or complexity of the sound can be varied. However, with conventional FM, an annoying pitch shift occurs. With the New Timbral Oscillator, Linear FM avoids this pitch shift, making it possible to maintain accurate pitch control while changing the quality of sound. A built-in VCA assures accuracy and provides dynamic voltage control of Linear FM Depth.
Wizardry: Patching a waveform back into the attenuated VC input gives interesting results. The oscillators respond to negative control voltages, allowing real vibrato, and letting you extend the low end of the frequency range if you have a negative bias source handy.
Of course, conventional exponential FM is also available on the New Timbral Oscillator. The New Timbral Oscillator offers two voltage control inputs calibrated to one volt per octave and one variable voltage control input. One of the calibrated inputs incorporates a variable Portamento. This allows gliding from pitch to pitch at a voltage-controllable rate, set at each oscillator rather than from the controller (such as a keyboard), and therefore independently variable at each New Timbral Oscillator. All of the output levels are "hot", greater than +4 db to ensure maximum signal-to-noise ratio. A Sync input is provided for locking the NTO to another oscillator's fundamental, harmonic, or sub-harmonic frequency.
Precision Oscillator (PCO)
The Precision VCO is a versatile, voltage controlled oscillator offering three high quality waveform outputs (sine, triangle, and sawtooth) and both linear and exponential frequency modulation capabilities. A front panel switch conveniently extends the range of the PCO from the audio range (16 to 16,000 Hz) to a sub-audio range (.1 to 200 Hz) for use as a Low Frequency Oscillator.
EXCELLENT RESPONSE, TRACKING AND STABILITY
Featuring the identical exponential response, exceptional tracking characteristics, and perfect temperature stability as the NTO, the PCO is especially suited for use with the NTO as a modulation source for dyanamic depth linear FM.
Two calibrated one volt per octave inputs as well as a variable processing input are provided for complex frequency control. FM depth can be varied with the front panel adjustment. All output levels are "hot", greater than +4 db to insure maximum signal to noise ratio when used with subsequent processing. A Sync input is also available for locking the PCO to another oscillator's fundamental, harmonic, or sub-harmonic frequency.
Dual Comparator (COM)
The DUAL COMPARATOR (COM) provides several often useful house-keeping functions within the Serge system:
- Logical Decisions: If the + input is greater than the - input, then the output will be high. If not, then the output will be low.
- Level Detection. A pulse will be generated whenever an input voltage reaches a pre-set threshold. For example, when an envelope detector reaches a certain loudness level, it can be used with the Comparator to generate a pulse to activate or de-activate other events programmed within the synthesizer.
- Voltage variable pulse width modulation of any of the Serge oscillators.
- "Squaring" audio signals, whereby frequency related pulses are derived from an input signal. These pulses can be used for frequency sub-division (via a Dual Slope Generator or Sequencer), or as raw audio, rich in harmonic content.
In addition to the +/- inputs, each of the Comparators include a front-panel knob to manually set a threshold.