Oscillator A; Frequency Knob; Octave Rotary Switch; Sawtooth Shape Switch - Behringer Pro-1 Operation Manual

AP099 Revision 1.01 CM100B

Oscillator A

OSC A is an audio frequency source always under control of the MIDI input.
Frequency
Knob
Adjusts initial
frequency
continuously over a
one-octave range.
Octave Rotary
Switch
Transposes initial frequency over a four-octave range.

Sawtooth Shape Switch

Enables full-level wave shape containing all harmonics. This unmodified shape is often
described as "brassy."

Pulse Shape Switch

Enables full-level wave shape whose harmonic content depends on setting of PULSE WIDTH
knob.
If neither wave shape switch is on, OSC A will have no output to the MIXER. If both wave
shape switches are on, the sawtooth and pulse 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 pulse wave duty cycle from 0 to
100%. A 50% duty-cycle pulse, also called a square wave, can be obtained by setting the
knob to 5, then carefully adjusting for the dropout of the second harmonic (the first octave
overtone). At the extreme knob settings the pulses may "thin out" until they degenerate to dc,
resulting in no output signal. This knob has no effect on the sawtooth wave.

SYNC Switch

Forces OSC A to follow OSC B in hard synchronisation. Intermediate FREQUENCY settings
will produce unusual timbres at the next lower harmonic of OSC B. When a wide-width pulse
is selected for OSC A in sync with OSC B, and OSC B's frequency is set much higher than
OSC A, the signal from OSC A may degenerate to DC since the pulse is not given a chance
to discharge before being resynced.
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