Behringer 921B OSCILLATOR Quick Start Manual

Quick Start Guide
921B OSCILLATOR
Legendary Analog VCO Module
for Eurorack
Controls
(5)
(6)
(7)
(8)
FREQUENCY – This knob manually adjusts the frequency
(1)
in semitones for the 921B oscillator circuit. This oscillator
can generate both audio and sub-audio frequencies for
control or audio.
RANGE – This knob sets the general frequency range of
(2)
the oscillator in octaves, numbered to match pipe organ
notations, which can then be adjusted up or down by
semitones with the FREQUENCY knob.
921AB LINK FREQ – These parallel jacks accept frequency
(3)
control voltage signals from a 921A module via cables with
3.5 mm TS connectors. The parallel wiring of the jacks
also allows a control voltage signal to be sent through and
back out to drive additional 921B modules.
921AB LINK WIDTH – These parallel jacks accept 921A
(4)
control voltage signals for the rectangular wave width
parameter via cables with 3.5 mm TS connectors. The
parallel wiring of the jacks also allows a control voltage
signal to be sent through and back out to drive additional
921B modules.
NOTE: If the 921B input voltage exceeds the range of 0 to
+6 V, the excess voltage could result in the width being
0% or 100%, which means no waveform will be present
V 1.0
at the square wave output until the control voltage is
returned to the normal range. When using 921B with a
921A driver, the 921A's WIDTH OF RECTANGULAR WAVE
knob can offset the control voltage output from 921A to
compensate. For example, when 921A's WIDTH knob is set
to 50%, the 921A's normal control voltage range into 921B
becomes -3 V to +3 V.
SYNC WEAK/OFF/STRONG – Use this switch to set how
(5)
closely 921B follows the sync signal routed in via the SYNC
IN jack. If the SYNC IN input is not required, select the
center OFF switch position.
SYNC IN – Use this jack to route an external sync
(6)
signal into the 921B module via cables with 3.5 mm TS
(1)
connectors. A sawtooth waveform is recommended to
produce the best sync results.
AC MOD – Use this AC-coupled input jack to control
(7)
frequency modulation via a control signal.
(2)
DC MOD – Use this DC-coupled input jack to control
(8)
frequency modulation via a control signal.
WAVEFORM OUTPUTS – Use these jacks to route
(9)
oscillator signals out of the module via cables with
3.5 mm jacks. Four waveforms are available: sine,
(3)
triangular, sawtooth and rectangular.
Power Connection
(9)
(4)
The 921B OSCILLATOR module comes with the required power
cable for connecting to a standard Eurorack power supply system.
Follow these steps to connect power to the module. It is easier to
make these connections before the module has been mounted
into a rack case.
1. Turn the power supply or rack case power off and
disconnect the power cable.
2. Insert the 16-pin connector on the power cable into the
socket on the power supply or rack case. The connector has
a tab that will align with the gap in the socket, so it cannot
be inserted incorrectly. If the power supply does not have
a keyed socket, be sure to orient pin 1 (-12 V) with the red
stripe on the cable.
3. Insert the 10-pin connector into the socket on the back of
the module. The connector has a tab that will align with the
socket for correct orientation.
4. After both ends of the power cable have been securely
attached, you may mount the module in a case and turn on
the power supply.