Gilderfluke&Co 16 Bit CD-Quality Digital Audio Systems - Manual (Page 14)

These are unavailable to the rest of the audio system when the Intelligent Public Address System is used
on a DR-3000 installation. The PA System is unavailable if the repeater is using the second Digital Audio
Buss bank.
V
OLTAGE
C
ONTROLLED
A
MPLIFIER
(VCA):
A Voltage Controlled Amplifier (ÔVCAÕ) is an electronic component which is used to adjust the volume
of an audio signal remotely by applying a control voltage. Although the AB/DR-3000s donÕt actually have
any real VCAs on them, several VCA functions are simulated inside the AB/DR-3000's Digital Signal
Processor (DSP). These functions can be used to adjust any of the different audio signals on the AB/DR-
3000s:
1) Left volume level.
2) Right volume level.
3) Left half muted level.
4) Right half muted level.
5) Left Bass level.
6) Left Treble level.
7) Right Bass level.
8) Right Treble level.
9) Digital Mix Bus input volume level. Any of the four possible inputs from the Digital Audio Mix Bus
can be adjusted remotely.
10) Digital Mix Bus Output volume level. Any of the four possible outputs to the Digital Audio Mix
Bus can be adjusted remotely.
The control signals for these ÔVCAsÕ can be fixed at a preset level or come from one of three different
sources. These sources are:
1) Front panel. Any of these signals can be set to be adjusted from the buttons on the front of
the AB/DR-3000.
2) DMX-512 input channels. Up to four DMX-512 channels can be used at one time.
3) Any one of the eight 0-10 volt analog inputs. (Only two of these are available on the outside
of an AB-3000, although the other six inputs are still available inside the unit if you need them.)
4) RS-422 serial port commands. The serial command structure allows up to eight different Ôvol-
ume zonesÕ to be controlled.
When using the analog voltage inputs, the control signal is a simple 0 to 10 VDC signal just as you
would feed to a lamp dimmer. This can be fed to each card through any of the eight 'VCA BUS' lines
which are connected to all the DR-3000s in a cage. Any number of DR-3000s can use the same analog
VCA bus line. The pinout of the VCA Bus connector is compatible with the analog outputs from all of
Gilderfluke & CompanyÕs Animation Control Systems and MA-100 PA MASTER. Using the Intelligent PA sys-
tem, commands from the PA STATIONS can be used to ramp the levels of these outputs up and down to
control the volume of a group of AB/DR-3000s. Serial commands sent to the MA-100 can also control
these outputs directly.
All the control functions are normalized for ÔlogarithmicÕ response. This means that a 50% control sig-
nal will give a 50% perceived volume level.
To keep external inputs from being set too high or too low, any signal that is controlled from an exter-
nal input can be limited to within a user defined range. This range of adjustment can only be set
through the serially accessed configuration screens.
S
HELVING
E
QUALIZER
:
The Shelving Equalizer can be used to adjust the output filters of the AB/DR-3000 to compensate for
slight errors in the original recording, speakers or other parts of the installation. Although not a full graph-
ic equalizer, these bass and treble controls can be used to cover a multitude of sins.
R EAL T IME C LOCK :
A very accurate real time clock is available as an option on both the DR-3000 and AB-3000 AB/DR-
3000s. When this option is installed, the AB/DR-3000s can be configured to chime the quarter hours, toll
the full hours, and play any specific spiel at any specific time of the day or night. To keep from disturbing
G ILDERFLUKE & C O . ¥ 205 S OUTH F LOWER S T . ¥ B URBANK , C ALIF . 91502-2102 ¥ 818/840-9484 ¥ FAX 818/840-9485
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