페이지 인쇄
¨
902
The CV input provides direct access to the control port of the dbx VCAof the 902 for gain control. This provides the
user with the ability to use the 902 as an automatable level control. The dbx VCA provides linear-gain tracking in
decibels over a range of -100 to +40 dB with 1% accuracy. An output of 0 V produces 0 dB of gain through the
VCA. The control port should be driven by an op-amp or other low-impedance source. A bypass capacitor may be
required between the CV input and ground to prevent the audio signal from bleeding into this control port and caus-
ing modulation distortion.
U
C
V
SING THE
ONTROL
OLTAGE
The control voltage output is a DC voltage which changes in proportion to the amount of gain change being pro-
duced by the 902. The relationship between this voltage and the amount of gain change is expressed as
CV=50mV/dB gain change. The CV output is low impedance and capable of driving bridged loads of more than 10
k½ and less than .01µf without affecting the operation of the 902.
Figure 3: Control Voltage
Connections
S
PECIFICATIONS
Input Impedance:
Output Impedance:
Maximum Input Level:
Maximum Output Level:
Frequency Response:
Dynamic Range:
Distortion:
Equivalent Input Noise:
Attack Rate:
Release Rate:
De-Essing Range:
Maximum ÒEssÓ Attenuation:
De-Ess Crossover Point:
Filter Type:
Gain:
Controls:
Switches:
Indicators:
Metering:
Power Supply Requirements:
Dimensions:
Note: specifications subject to change.
O
UTPUT
A
B
C
D
20 k½ balanced, >10 k½ unbalanced
22 k½, into 600 ½ or greater
+24 dBu
+24 dBu into 600 ½ or greater
20 Hz - 20 kHz (+0/-3dB)
115 dB
Typically .008 % at 1 kHz
-90 dBu, 20 Hz - 20 kHz Bandwidth, unweighted
Program-dependent, 2 ms for 10 dB above threshold, 600µs for 20 dB above threshold, to achieve
63% gain reduction
925 dB/sec
Operates uniformly over input range of -40 dBu to +24dBu without requiring adjustment
Variable 0 to 20 dB
Variable 800 Hz to 8 kHz
12 dB/ocatve, phase coherent
Unity
Frequency, Range
IN/OUT, Mode (HF ONLY/NORMAL)
IN/OUT, HF ONLY
LED Column: 1, 2, 3, 4, 6, 8, 10, 12, 15, 20 dB gain reduction
±15 V Regulated at 60 mA; ±24 V unregulated at 30 mA
Front Panel: 3U high (54Ó, 13.4 cm) x 12Ó W, (3.8 cm); card depth behind front panel: 92Ó (24.2 cm)
5
Audio
Input
Audio
Output
CV
Out
CV
In