Series, 160s, 160sl – dbx 160SL User Manual
Page 24: Operations, Technical, Manual, Connection, Connection installation installation, Introduction
20
160S
lue
series
b
160S
160S
160S
controls
controls
160S
notes
notes
160S
160S
160S
Operations
160S
160S
160S
160S
160S
160S
160S
160S
160S
160S
160S
160S
160S
160S
160S
Operations
Inspection
Inspection
Operating
Operating
Operating
Operating
Connection
Connection
Installation
Installation
Technical
Technical
Introduction
Introduction
to your system
to your system
considerations
considerations
contents
contents
concept
concept
diagram
diagram
applications
applications
support and factory service
support and factory service
160S
Specifications
Specifications
160S
160S
160S
160S
160S
160S
Manual
Manual
Design
Design
Block
Block
Controls
Controls
Advanced
Advanced
Warranty
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The 160SL as a line amplifier
To use the 160SL as a line amplifier, adjust the Compression control to fully counterclockwise (1:1 position), the
Threshold control to full clockwise position (+10) and the Output Gain control to whatever setting is required
for the application. Remember that, as with any amplifier, excessive gain may lead to output clipping of high level
signals. To add compression, adjust the Compression control and the Threshold control to the desired settings.
Sidechain Applications
Frequency-weighted compression
It is possible to separate certain vocals and instruments from a mix by frequency-weighted compression. With an
equalizer inserted in the sidechain circuit (but not in the audio path), the equalization settings do not shift the
timbre or frequency response of the audio signal. They merely alter the threshold response of the compressor on
a
frequency-weighted basis (see diagram below).
Operating Level
Headroom
Clipping
Noise Floor
Useable dynamic range
Clipped signal heavily distorted
Audio levels below here are not heard, because of noise
+10
0
-10
-20
time
+10
0
-10
-20
time
input
dBu
Figure 2
Figure 1
Figure 3
Figure 4
input
dBu
+10
0
-10
-20
time
+10
0
-10
-20
time
output
dBu
output
dBu
INPUT OUTPUT
INPUT OUTPUT
CHANNEL ONE
CHANNEL TWO
A
B
2
1
3
Jensen
®
Output
Transformer
Jensen
®
Output
Transformer
10k 1W
GND
Switch
GND
Switch
BALANCED FLOATING OPERATION
UNBALANCED FLOATING OPERATION
Chassis
Ground
Chassis
Ground
Chassis
Ground
Ground Switch open
Unbalance Switch open
Ground Switch open
Unbalanced Switch closed
(6dB drop in output level)
Jensen
®
Output
Transformer
Jensen
®
Output
Transformer
10k 1W
GND
Switch
GND
Switch
BALANCED GROUND-
REFERENCED OPERATION
UNBALANCED GROUND-
REFERENCED OPERATION
Chassis
Ground
Chassis
Ground
Ground Switch closed
Unbalance Switch open
Ground Switch closed
Unbalance Switch closed
(6dB drop in output level)
+
-
+
-
+
-
+
-
Source
Device
(mixer)
EQ
IN
OUT
Audio
Outputs
Source
Device
(mixer)
Audio
Outputs
DELAY
Audio
Inputs
Audio
Outputs
Sidechain
Return
Sidechain
Send
Audio
Inputs
Audio
Outputs
Sidechain
Return
Sidechain
Send
2
1
3
Chassis
Ground
2
1
3
Chassis
Ground
2
1
3
Chassis
Ground
160SL
160SL
UL60065
FUSE:
T 500mA L
250V
Frequency-weighted compression
With this arrangement, raising certain frequencies on the equalizer causes them to be suppressed in the audio
signal. A relatively high threshold setting can allow normal sounds to be unaffected while solo and very loud
sounds are held back. (Of course, when compression does occur, the level of the entire program is affected.)
Depending on the threshold setting, lower level fundamentals or harmonics will not cause compression, and the
program is not subject to the phase shift normally caused by program equalization.
During the recording of cymbals and tom-toms, a compressor with an equalizer in the sidechain path can help
prevent tape saturation. The equalizer can be adjusted for boost with a peak of about 5kHz, causing the cymbal to
be compressed on a very loud crash, stopping tape saturation at high frequencies, where there is less headroom.
However, gentle tapping of a drumstick or brushing of the cymbal will not be held back. Assuming the tom-tom
is a lower frequency instrument and can be better tolerated by the tape, it has less need for compression. The
equalization in the sidechain circuit means that the compressor is not triggered as readily by a loud tom-tom beat
as by an equally loud cymbal crash.
The converse of the above EQ technique may be used: dipping the equalizer bands causes any sound with domi-
nant energy in the affected register to pull the level up because the 160SL will detect a need for less compression.
160SL
lue
series
b
160SL
160SL
160SL
controls
controls
160SL
notes
notes
160SL
160SL
160SL
Operations
160SL
160SL
160SL
160SL
160SL
160SL
160SL
160SL
160SL
160SL
160SL
160SL
160SL
160SL
160SL
Operations
Inspection
Inspection
Operating
Operating
Operating
Operating
Connection
Connection
Installation
Installation
Technical
Technical
Introduction
Introduction
to your system
to your system
considerations
considerations
contents
contents
concept
concept
diagram
diagram
applications
applications
support and factory service
support and factory service
160SL
Specifications
Specifications
160SL
160SL
160SL
160SL
160SL
160SL
Manual
Manual
Design
Design
Block
Block
Controls
Controls
Advanced
Advanced
Warranty
Warranty
lue
series
b