Analogue Solutions Concussor - Manual (Page 25)

ANALOGUE SOLUTIONS
CONCUSSOR e&oe (c) 12-2007 25
VCO - Voltage Controller Oscillator
Introduction
VCO is a single VCO laid out in a similar way to the VCO sec tion you would find on a monosynth. VCO in cludes a glide
(slew) function, so this is a great bonus. The VCO can go down to low fre quen cies so they can be used as an LFO.
Voltage Controlled Oscillators (VCOs) in gen er al
The VCO or signal generator, commonly found on most music syn-
thesizers consist of an ex po nen tial amplifier, a resetable in te gra tor and
waveshaping circuitry. ‘Voltage Controlled Os cil la tor’ means an oscillator
whose frequency can be controlled by an ex ter nal voltage.
A VCO is responisble for the pitch of a sound and its basic tim bre. Most
VCOs will offer a va ri ety of wave forms. Some VCOs offer the facility to
alter the pulse width of a square wave either manually or with a voltage
(pulse width modulation).
Controls In Detail
Tune
The VCO has a wide ranging tune control. Turning Tune alters the
basic pitch of the oscillator.
Glide
Turning up Glide adds portamento to the oscillator, so the pitch will
bend (slide) up or down to each note (as opposed to a sudden change).
The higher the setting, the longer the oscillator takes to reach its new
note. Not many VCO modules give you the all important Glide control
as standard!
Pulse Width
You can alter the pulse width (duty cycle) of the square wave. Turning
this gives a sound similar to chorusing. In the centre position a square
wave is produced.
Sawtooth Level
This sets the output volume of the sawtooth waveform output.
Square Level
This sets the output volume of the square waveform output.
Sockets in Detail
CV in
This socket is the pitch CV control input and is used to control the pitch of the oscillator.
PW
This is a pulse width control CV input. Use a -12 to +12V voltage in this socket to alter the pulse width of the oscil-
lator square wave.
Sync In
This is an oscillator Sync reset input.
Sawtooth Out
This is the audio output for the sawtooth waveform. Its level is affected by the sawtooth level pot.
Square Out
This is the audio output for the square waveform. Its level is affected by the square level pot.