Moog Music Voyager Old School - Manual (Page 8)

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Voyager OS User’s Manual - The Basics
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Voyager OS User’s Manual - The Basics
To understand the signal fl ow of the Voyager OS, it’s helpful to consider the three types of signal rout-
ings in the system: the audio path, the control voltage path, and the modulation path.
Audio Path
The Voyager’s audio path includes all of the signal sources and signal modifi ers that produce an audio
output. These include the oscillators, mixer, fi lters and amplifi ers (VCAs).
The Oscillator section includes controls for selecting the octave and waveforms, adjusting the tuning of
the second and third oscillators, for setting the oscillator sync and linear FM functions, and for setting the
frequency range and keyboard control for Oscillator 3.
The Mixer section is where the oscillators and other sound sources (noise and external input) are
selected and mixed together. The output of the Mixer section is routed to the Filter section through a
Mixer Out/Filter In jack on the Voyager’s rear panel. This jack allows you to interrupt the signal routing
between the Mixer and Filter to insert an external effect, or take the output of the Mixer directly.
The Filter section is responsible for altering the harmonic content of the combined sound sources. The
Voyager’s Filter section contains two fi lters that work together in two different modes.: Dual LP and
HP/LP. Dual LP mode features two lowpass fi lters in parallel, while HP/LP (Highpass-Lowpass) mode
features a lowpass and highpass fi lter in series, creating a Bandpass fi lter response. In either mode, the
Filter Cutoff control affects the cutoff frequency of both fi lters, and the Spacing control is used to adjust
the difference between the cutoff frequencies. The outputs of the fi lters are routed to the Voltage
Controlled Amplifi ers (VCAs).
The VCAs shape the volume level of the audio signal using time-varying control signals called Envelopes.
The Envelopes section (part of the control voltage path) contains one Envelope Generator to control
the Filters, and one Envelope Generator to control the VCAs. The Voyager’s audio path is illustrated
below.
Signal Flow
The Voyager OS Audio Path