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Owner’s Manual
Owner
’s Manual
•
When connecting an unbalanced output to a bal-
anced input, be sure that the signal high (hot)
connections are wired to each other. The unbal-
anced ground (earth) connection should be wired
to the low (cold) and the ground (earth) connec-
tions of the balanced input. If there are ground-loop
problems, try disconnecting the unbalanced ground
(earth) connection from the balanced input ground
(earth) connection, leaving the unbalanced ground
connected to the balanced input low (cold) con-
nection only.
In some cases, you may have to make up special
adapters to interconnect your equipment. For example,
you may need a balanced XLR female connected to an
unbalanced 1/4" TS phone plug. Many common adapters
can be found at your local electronics supply store.
The balanced-to-unbalanced connection has been
anticipated in the wiring of Mackie jacks. A 1/4" TS plug
inserted into a 1/4" TRS balanced input, for example,
will automatically unbalance the input and make all the
right connections. Conversely, a 1/4" TRS plug inserted
into a 1/4" unbalanced input will automatically tie the
ring (low or cold) to ground (earth).
TRS Send/Receive Insert Jacks
Mackie’s single-jack inserts are three-conductor 1/4"
TRS phone jacks. They are unbalanced, but have both
the mixer output (send) and mixer input (return)
signals in one connector.
The sleeve is the common ground (earth) for both
signals. The send from the mixer to the external unit is
carried on the tip, and the return from the unit to the
mixer is on the ring.
“tip”
this plug connects to one of the
mixer’s Channel Insert jacks.
“ring”
tip
ring
sleeve
SEND to processor
RETURN from processor
(TRS plug)
Using the Send Only on an Insert Jack
If you insert a 1/4" TS (mono) plug only partially (to
the fi rst click) into a Mackie insert jack, the plug will
not activate the jack switch and will not open the insert
loop in the circuit (thereby allowing the channel signal
to continue on its merry way through the mixer).
This allows you to tap out the channel’s signal at that
point in the circuit without interrupting normal operation.
Note:
Do not overload or short-circuit
the signal you are tapping from the
mixer. That will affect the internal
signal.
If you push the 1/4" TS plug in to the second click,
you will open the jack switch and create a direct out,
which does interrupt the signal in that channel.
Direct out with no signal interruption to master.
Insert only to first “click.”
Channel Insert jack
Channel Insert jack
Channel Insert jack
Direct out with signal interruption to master.
Insert all the way in to the second “click.”
For use as an effects loop.
(TIP = SEND to effect, RING = RETURN from effect)
MONO PLUG
MONO PLUG
STEREO
PLUG
Mults and “Y”s
A mult or “Y” connector allows you to route one output
to two or more inputs by simply providing parallel wir-
ing connections. You can make “Y”s and mults for the
outputs of both unbalanced and balanced circuits.
Remember:
Only mult or “Y” an
output into several inputs. If you need
to combine several outputs into one
input, you must use a mixer, not a
mult or a “Y.”
Y-Cord Splitter
Summary of Contents for 1640
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