Channel Inserts - Mackie Digital 8 Bus Owner's Manual

Pin 1 + Ch 8
Pin 2 shield Ch 8
Pin 3 – Ch 7
Pin 4 + Ch 6
Pin 5 shield Ch 6
Pin 6 – Ch 5
Pin 7 + Ch 4
Pin 8 shield Ch 4
Pin 9 – Ch 3
Pin 10 + Ch 2
Pin 11 shield Ch 2
Pin 12 – Ch 1
Pin 13 N/C
Figure 4-5. DB-25 Pin-out Identification
DIGITAL EFFECTS
FX Cards located
behind this cover plate.
DIGITAL EFFECTS
In addition to the internal effects, the Digital
8•Bus provides several ways to connect
external effects devices.

Channel Inserts

Channels 1–12 are equipped with INSERT
jacks for connecting external processors into
each channel's signal path. The insert point
comes after the Mic/Line preamp and just
before the analog-to-digital converter.
This is a TRS jack specially configured as a
combination Send/Return connection point. It
is configured with the Tip = Send, Ring =
Return, and Sleeve = Ground. This has become
somewhat of a standard in the industry, and
Ch16 Ch24 Pin 14
Ch16 Ch24 Pin 15
Ch15 Ch23 Pin 16
Ch14 Ch22 Pin 17
Ch14 Ch22 Pin 18
Ch13 Ch21 Pin 19
Ch12 Ch20 Pin 20
Ch12 Ch20 Pin 21
Ch11 Ch19 Pin 22
Ch10 Ch18 Pin 23
Ch10 Ch18 Pin 24
Ch 9 Ch17 Pin 25
many cable manufacturers make cables
especially for this purpose. With nothing
plugged into the INSERT jack, the send signal
is directly connected to the return pin via the
normalling jack.
The INSERT jack can also be used as a direct
out from the mic preamps to tape. If you insert a
TS (mono) 1/4" plug only partially into the
INSERT jack (to the first click), 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 the
channel signal at that point in the circuit
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.
ring
tip
This plug connects to one of the
mixer's Channel Insert jacks.
– Ch 8 Ch16
+ Ch 7 Ch15
shield Ch 7 Ch15
– Ch 6 Ch14
+ Ch 5 Ch13
shield Ch 5 Ch13
– Ch 4 Ch12
+ Ch 3 Ch11
shield Ch 3 Ch11
– Ch 2 Ch10
+ Ch 1 Ch 9
shield Ch 1 Ch 9
Do not overload or short-
circuit the signal you are
tapping from the mixer.
Doing so will affect the
internal signal.
(TRS plug)
sleeve
Ch24
Ch23
Ch23
Ch22
Ch21
Ch21
Ch20
Ch19
Ch19
Ch18
Ch17
Ch17
1
+48V
PH
MIC
LINE IN
INSERT
AUX
1
SEND to processor
"tip"
"ring"
RETURN from processor
Connections
4-3