OSC A is an audio-frequency source always under control of its FREQUENCY knob, the keyboard, PITCH wheel, and MASTER TUNE knob. Its frequency (FREQ) can be modulated by the LFO-MOD and POLY-MOD systems. PULSE-WIDTH (PW) can also be modulated by the LFO-MOD system.
Figure 7-1
FREQUENCY knob: Adjusts oscillator pitch in semitones, over a four-octave range. For basic "concert" tuning, where the middle A on the keyboard equals 440 Hz, set the FREQUENCY knob two octaves above "0" on the dial. Exact oscillator pitch is finetuned with the MASTER TUNE knob.
SYNC switch: Forces OSC A to follow OSC B in "hard" synchronization. Depending on the setting of the OSC A FREQUENCY knob, OSC A will either lock to harmonic frequencies of OSC B, or produce unusual timbres at the next lower harmonic of OSC B.
If SYNC is on, and a very narrow or wide pulse is selected for OSC A, and OSC B's frequency is set much higher than OSC A, the output from OSC A may disappear. (Because the pulse is not given a chance to discharge before being re-synced, it degenerates from audio to dc.)
Even if no OSC B waveshapes are switched on, SYNC still operates, so the overall pitch range of the program will be determined by the OSC B FREQUENCY knob setting...
SYNC is used in Factory Programs 17, 26, 76, and others.
SAWTOOTH SHAPE switch: Enables full-level waveshape containing all harmonics.
This basic shape is often described as "brassy."
TRIANGLE SHAPE switch: Enables full-level triangle wave, containing little harmonic energy, thus having a dull tone.
PULSE SHAPE switch: Enables full-level waveshape whose harmonic content, thus timbre, depends on the setting of the PULSE WIDTH knob.
If no waveshape switch is on, OSC A will have no audio output. If two or three waveshape switches are on, all waves are mixed at full level and supplied as OSC A's output to the MIXER.
PULSE WIDTH knob: Adjusts the harmonic content of the pulse wave by setting its duty cycle from approximately 1 to 99%. A 50% duty-cycle pulse (having only odd harmonics), also called a square wave, can be obtained by setting the knob to approximately 5, then carefully adjusting for the dropout of the second harmonic (the first octave over tone). This knob is only effective if the PULSE SHAPE switch is on. At the extreme knob settings the pulses will "thin out" until they degenerate to dc, resulting in no audio output.
This knob has no effect on the sawtooth or triangle waves.
7-2 OSCILLATOR B
OSC B is identical to OSC A, except instead of the SYNC switch there is a FINE knob, OSC B can also be a POLY-MOD modulation source. It can't be modulated by POLYMOD.
Figure 7-2
FINE knob: Raises OSC B frequency up to one semitone. This allows detuning the oscillators, typically, for a warmer, more natural sound.
Figure 7-3
GLIDE knob: When set to the KEYBOARD CV, which controls oscillator pitch, instantly steps between notes. As the GLIDE knob is advanced, the CV does not step between the notes, but begins to "slew." This introduces "portamento" between notes.
See also pages 3-4 and 3-5.
Figure 7-4
MIXER knob: Adjusts the ratio of OSC A and OSC B output to the FILTER.
P6K Oscillator
Description
Another oscillator and this time it's a twofer. It uses the P6000 atom which I guess is based on the Prophet 600. Nice soundType
OSCModule
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Sequential Circuits
Source » Manual » CM600A 12/82 ...
7-1 OSCILLATOR A
OSC A is an audio-frequency source always under control of its FREQUENCY knob, the keyboard, PITCH wheel, and MASTER TUNE knob. Its frequency (FREQ) can be modulated by the LFO-MOD and POLY-MOD systems. PULSE-WIDTH (PW) can also be modulated by the LFO-MOD system.Figure 7-1
FREQUENCY knob: Adjusts oscillator pitch in semitones, over a four-octave range. For basic "concert" tuning, where the middle A on the keyboard equals 440 Hz, set the FREQUENCY knob two octaves above "0" on the dial. Exact oscillator pitch is finetuned with the MASTER TUNE knob.
SYNC switch: Forces OSC A to follow OSC B in "hard" synchronization. Depending on the setting of the OSC A FREQUENCY knob, OSC A will either lock to harmonic frequencies of OSC B, or produce unusual timbres at the next lower harmonic of OSC B.
If SYNC is on, and a very narrow or wide pulse is selected for OSC A, and OSC B's frequency is set much higher than OSC A, the output from OSC A may disappear. (Because the pulse is not given a chance to discharge before being re-synced, it degenerates from audio to dc.)
Even if no OSC B waveshapes are switched on, SYNC still operates, so the overall pitch range of the program will be determined by the OSC B FREQUENCY knob setting...
SYNC is used in Factory Programs 17, 26, 76, and others.
SAWTOOTH SHAPE switch: Enables full-level waveshape containing all harmonics. This basic shape is often described as "brassy."
TRIANGLE SHAPE switch: Enables full-level triangle wave, containing little harmonic energy, thus having a dull tone.
PULSE SHAPE switch: Enables full-level waveshape whose harmonic content, thus timbre, depends on the setting of the PULSE WIDTH knob.
If no waveshape switch is on, OSC A will have no audio output. If two or three waveshape switches are on, all waves are mixed at full level and supplied as OSC A's output to the MIXER.
PULSE WIDTH knob: Adjusts the harmonic content of the pulse wave by setting its duty cycle from approximately 1 to 99%. A 50% duty-cycle pulse (having only odd harmonics), also called a square wave, can be obtained by setting the knob to approximately 5, then carefully adjusting for the dropout of the second harmonic (the first octave over tone). This knob is only effective if the PULSE SHAPE switch is on. At the extreme knob settings the pulses will "thin out" until they degenerate to dc, resulting in no audio output.
This knob has no effect on the sawtooth or triangle waves.
7-2 OSCILLATOR B
OSC B is identical to OSC A, except instead of the SYNC switch there is a FINE knob, OSC B can also be a POLY-MOD modulation source. It can't be modulated by POLYMOD.Figure 7-2
FINE knob: Raises OSC B frequency up to one semitone. This allows detuning the oscillators, typically, for a warmer, more natural sound.
Figure 7-3
GLIDE knob: When set to the KEYBOARD CV, which controls oscillator pitch, instantly steps between notes. As the GLIDE knob is advanced, the CV does not step between the notes, but begins to "slew." This introduces "portamento" between notes.
See also pages 3-4 and 3-5.
Figure 7-4
MIXER knob: Adjusts the ratio of OSC A and OSC B output to the FILTER.
... CM600A 12/82