9
phone amp” chip, we use a high-current
version of our main output amplifier, which
is why it can really clean out your cochlea if
you crank it up too far… but still be a very
clean signal source.
Metering
The MS 1202’s 3-way peak metering sys-
tem is made up of two columns of twelve
LED’s (21) and an INPUT CH. METERING
switch (22).
Thanks to the MS 1202’s wide dynamic
range, you can get a good mix with peaks
flashing anywhere between –30 and +10dB
on this display. Most PA amps clip at +4, and
most recorders aren’t so forgiving either. For
best real-world results, try to keep your
peaks below +7.
In combination with the INPUT CH. i/ME-
TERING button, the display can be used to
monitor three different sources:
•
Stereo Output.
This is the normal
function you’d expect from any mixer. It’s
displayed when the INPUT CH. METER-
ING button is in the OUT position. But
don’t go away, there’s more! Press the
INPUT CH. METERING button IN and you
get input metering as well.
•
Channel Operating Level.
The right
column of LED’s displays the overall
operating level of all 12 channels and AUX
Returns (pre-
Master Gain). To
monitor just one
channel, turn down
the others.
•
Mic Input.
The left
column of LED’s
displays the
combined operat-
ing levels of
Channel 1–4’s mic
preamps. By using
just one channel at
a time, you can use
this feature to
TRIM for 0dB
operating level
(explained else-
where in detail).
Avoid lighting the
red CLIP LED’s.
With
the INPUT CH. ME-
TERING button OUT,
watch the bouncing
LED’s to control the
OUTPUT SECTION
Here’s where it all comes together.
Master gain
This controls both stereo MAIN and TAPE
outputs from OFF (fully counterclockwise),
through Unity Gain at the center detent, to
10dB of extra gain at fully clockwise. Most of
the time this is run between Unity and off.
Phones
As you might expect, this control does the
same thing for the PHONES jack. The con-
trol range is from full OFF to loud. It’s totally
independent of the MASTER pot, so you can
use the headphone output to preview your
mix before fading up the main outputs.
You can also use the PHONES output to
independently drive a separate tape recorder
or PA system. We made sure the audio quality
at that output is the same audio quality as at
the main outputs.
Because the headphone signal is controlled
by the PHONES knob but not by the MASTER
gain knob, you can use this feature to:
•
Preview a mix.
Leave the MASTER
control all the way down while you listen
to the musicians’ intro or click track in
the headphones and then quickly bring
up the master for a clean entrance.
•
Serve as a totally isolated, high-quality
output
for a second tape recorder or PA
system. Instead of using a low-cost “head-
PHONES
O
O
+22
CLIP
MASTER
+10
O
O
U
+10
+4
+2
0
-2
-4
-7
-10
-20
+7
-30
TRIM
1-4
LINE IN
1-12
INPUT CH.
METERING
U
BAL.
0dBu
CAL
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20
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21
1202
CONTROLS
MS1202 MODIFICATION:
Convert AUX SEND 2 to pre-EQ/pre-fader
Channels 1–4 only.
(1) Remove bottom cover. You will be
working on the solder side (bottom)
of the circuit board.
(2) Locate this area on the circuit
board. Near the Aux Send 2 pots,
channels 1 thru 4.
(3) Cut trace here.
(4) Add jumper here.
PRE
POST
Any internal modification of the MS 1202 must be
performed by a competent electronic technician.
Mackie Designs accepts no responsibility in the
event of improperly performed modifications or
other damages and, in such cases, may declare
warranty privileges void.
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20
22
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