Special mackie connections, Rca plugs and jacks, Unbalancing a line – MACKIE 1202-VLZ3 User Manual

Page 22: Trs send/receive insert jacks, Using the send only on an insert jack

Advertising
background image



10-VLZ3

1202-

VLZ3

Special Mackie Connections

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 the three-conductor,

TRS-type 1⁄4" phone. They are unbalanced, but have
both the mixer output (send) and the mixer input
(return) signals in one connector. See Figure E.

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.

Using the Send Only on an Insert Jack

If you insert a TS (mono) 1⁄4" plug only partially (to

the first 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 or bus signal

without interrupting normal operation.

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. See Figure F
on the next page.

NOTE: Do not overload or short-circuit the signal you

are tapping from the mixer. That will affect the internal
signal.

RCA Plugs and Jacks

RCA-type plugs (also known as phono plugs) and

jacks are often used in home stereo and video equip-
ment and in many other applications (Figure D). They
are unbalanced and electrically identical to a 1⁄4" TS
phone plug or jack. See Figure C. Connect the signal to
the center post and the ground (earth) or shield to the
surrounding “basket.”

Unbalancing a Line

In most studio, stage and sound reinforcement situ-

ations, there is a combination of balanced and unbal-
anced inputs and outputs on the various pieces of
equipment. This usually will not be a problem in making
connections.

• When connecting a balanced output to an

unbalanced input, be sure the signal high (hot)
connections are wired to each other, and that
the balanced signal low (cold) goes to the
ground (earth) connection at the unbalanced
input. In most cases, the balanced ground
(earth) will also be connected to the ground
(earth) at the unbalanced input. If there are
ground-loop problems, this connection may be
left disconnected at the balanced end.

• When connecting an unbalanced output to a

balanced input, be sure that the signal high
(hot) connections are wired to each other. The
unbalanced ground (earth) connection should
be wired to the low (cold) and the ground
(earth) connections of the balanced input. If
there are ground-loop problems, try connecting
the unbalanced ground (earth) connection only
to the input low (cold) connection, and leaving
the input ground (earth) connection discon-
nected.

• In some cases, you will 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.

TIP

SLEEVE

TIP

SLEEVE

Figure D: RCA Plug

“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)

Figure E

Advertising