D i g i t a l 8 • B u s
32
Digital 8•Bus Overview
7. Digital 8•Bus Overview
Channel Strip Description
Refer to the foldout page at the end of this
manual for an overall view of the various sec-
tions described.
Channel Strip Section
There are 24 channel strips on the Digital
8•Bus. Channels 1–12 have both mic and line
input capability, and channels 13–24 have line-
level inputs only.
There are four tiers, or levels, to the input
strips. We refer to them as Fader Banks 1–4.
Fader Bank 1 includes the mic and line inputs
as described above. Fader Bank 2 includes 24
channels of tape inputs, which are accessed
through plug-in cards on the rear panel. You
can use any combination of Analog I/O cards
(AIO•8) or Digital I/O cards (DIO•8). Fader
Bank 3 controls the 16 internal effects returns
(FX 1–16), and the 8 ALT I/O returns (RET
1-8). You must have the optional ALT I/O card
installed to use these returns (AIO•8 or
DIO•8). Fader Bank 4 controls the 8 Virtual
Groups, 8 MIDI controllers, and the 8 Bus
Masters (BUS 1–8).
The channel strip on the Digital 8•Bus is
very much like the channel strip on an analog
mixer. It has the TRIM LEVEL control at the
top for adjusting the gain of the mic or line in-
put signal (channels 1–24 only), followed by a
MIC/LINE button (channels 1–12 only) for
switching between the mic and line input sig-
nals. The REC/RDY button arms the
corresponding track for recording via MIDI Ma-
chine Control (MMC), and the ASSIGN button is
used to assign channels to buses and the tape
outputs.
The WRITE button enables a channel for re-
cording to automation. In Touch mode, it is
unnecessary to press the WRITE button, because
the channel automatically goes into Write mode
as soon as a control is moved on the channel.
The channel V-Pot controls the pan and aux
send levels for the channel, depending on how
it is assigned in the V-Pot Assign Section and
Master V-Pot Section. Just below the V-Pot are
the Fader Bank Select LEDs, which indicate the
Fader Bank selected. If both of the LEDs are lit,
Bank 3 is selected (EFFECTS). If neither of the
LEDs are lit, Bank 4 is selected (MASTERS).
The SELECT button chooses a channel for
editing in the Fat Channel, as well as copying
and pasting channel settings. When the SOLO
button is pressed, Mackie’s exclusive RUDE
SOLO LIGHT in the Studio/Solo Section begins
flashing to let you know at least one channel is
soloed. All soloed channels are assigned to the
stereo solo bus, and appear at the CR (Control
Room) outputs.
The MUTE button mutes the signal after the
channel fader, prior to the output buses, includ-
ing BUS 1–8 and the L-R bus. It doesn’t affect
the Direct Out to Tape.
The Channel fader controls the signal level
from the channel to the bus or buses it is as-
signed to. It doesn’t affect the signal level from
the channel to the Tape Outputs. The Tape Out
signal is pre-fader. You can adjust the Tape Out
levels, however, without changing the input
Trim Level control. Press the LEVEL TO TAPE
button just below the Talkback Mic and the
channel V-Pots become Tape Send level controls.
The channel meters indicate post-EQ, pre-
fader levels. The audio level display is scaled in
digital dB FS, where 0 dB FS is +19 dBu, –15
dB FS is +4 dBu and minimum displayed
level is –50 dB FS. Markings screened next to
the LED ladders are denoted as –50 dB FS to
OL. Markings are similar in function to those of
digital recorders.
Note:
Typically, in digi-
tal recording devices
such as MDMs, HDRs,
or DATs, there is a built-
in overhead of 3 to 4 dB
above the 0 dB FS mark
to match the typical
maximum unbalanced
analog console bus out-
put value of +22 dBu.
The OL LED lights at
+22 dBu.
Master Section
Description
The Master Section
is divided into 12 sub-
sections.
Master Fader/
Bank Select
Section
This section con-
sists of the four
buttons used to select
the four Fader Banks,
the SHIFT button,
which is used to select
and deselect multiple
channels, and the Mas-
ter L/R Fader which controls the signal level
going to the L-R stereo bus.
TRIM
12
12
36
12
36
10
dB
30
20
10
40
5
5
U
60
50
FX 12
MIDI 4
MIC
0
60
-
20dB +40dB
LINE
ASSIGN
WRITE
MIC
REC/RDY
SELECT
MUTE
SOLO
SHIFT
MASTERS
MASTER
L/R
10
dB
30
20
10
40
5
5
U
60
50
1
-
24
25
-
48
49
-
72
(TRACK)
(MONITOR)
BANK SELECT
EFFECTS
MIC/LINE
TAPE IN