dbx 166 - Typical Hookups and Connections; Audio Input Connections

TYPICAL
HOOKUPS
All
1 66
connections are made through
tfie rear phone jacks; our figures in
this sec-
tim show
the wiring of plugs and cables to
make these connections. Again,
tip
is plus (or
high, or
hot), ring is minus (or low), and
sleeve
is
ground or shield (or
earth).
Audio inputs
and balanced and unbalanced sources
Your unit's two signai inputs are
balanced electronically with
differential ampli-
fiers. They won't unbalance a balanced source,
and they may be used with
unbaianced
sources as well.
Here's a general-purpose
diagram:
SIGNAL
FLOW
—
>
For maximum hum rejection,
avoid common grounding at the 166's
input and ouput.
The best starting
point Is to ground the
shield of the input Ce^le and
the source device
(ieaving it
unconnected to tiie 166) and to
ground the shield of the
output cable to the
ground of the 1
66
(leaving
it unconnected at the
receiving device).
A baianced line is
defined
as
two-conductor
shielded cable with each of the
two
center
conductors carrying the
signal but of opposite
polarity and equal but opposite
potential difference
from ground. An unbalanced line is a
slngle'^onductor
Yielded
cable with the center
conductor carrying the signal
and the shield at ground
potential.
Figure 1 shows the ccmnection
of baianced signal sources
to either audio input
jack.
Note that for this connection a
3-circuit phone plug is necessary, as is
dual-
conductor shielded cable. Sometimes the plug is
called a "stereo" phone plug
because it's
often used for such stereo circuits
as headphones.
AT TMI9
M
ir
H*.
OCVB.OPS
Figure 1:
Balanced sources
Figures
2a
and 2b show an
unbalanced source connected to these
inputs. In 2a, a
3-circuit phone
plug
is used (and the
ring is connected to the
shield), while in 2b a 2-cir-
cuit
("mono")
phone
plug is used. Since
this plug has a continuous sleeve
(where the 3-cir-
cuit plug has
both sleeve and ring), the
plug automatically shorts
the sleeve to the ring
at
the 166 input.
Figure 2a: Unbalanced
sources, dual^:onductor shielded cable
Figure
2b:
Same, single-conductor cable
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