4
Block Diagram
M•1200/M•1400
DIMENSIONS
CH 1
B
ALANCED
LINE INPUT
(T
R
S
)
CH 1
B
ALANCED
LINE INPUT
(XLR
-F)
LIMITER
LIMITER
ON
OFF
LOW CUT
FIL
TER
LOW P
ASS
FIL
TER
(SUBWOOFER)
+
–
80 VDC
+
–
90 VDC
TO
R
OID
AL P
OWER
TRANSFORMER
LAMP
INTERNAL
FUSE
MA
CKIE DESIGNS
M•1200/M•1400
BL
OCK DIA
G
RAM
(#011497DF)
FREQ
CD EQ
FREQ
OUTPUT
APPLIC
A
TION
SWIT
CH
AMP
MODE
SWIT
CH
63 Hz
125 Hz
FREQ
TO
LIMITER
ON
OFF
LOW CUT
FIL
TER
FREQ
CD EQ
FREQ
CH 1
GAIN
S
TEREO
MONO
BRIDGE
CH 2
GAIN
INVER
TING
UNIT
Y GAIN
AMPLIFIER
ON
OFF
SUB
ON
OFF
SUB
NC
NC
NC
MUTE
CH 1
PR
O
TECT
LED
CH 1
SHOR
T
LED
MUTE
CH 2
PR
O
TECT
LED
PO
W
E
R
AMPLIFIER
CH 1
SPEAKER
OUT
FUSE
–80VDC
FUSE
+80VDC
DC OFFSET
DETECT
SHOR
T
DETECT
METER
DRIVE
P
O
WER
AMPLIFIER
CH 2
SPEAKER
OUT
FUSE
–80VDC
FUSE
+80VDC
DC OFFSET
DETECT
TO
CH 1
MUTE
OL –3 –6 –9 –20 SIG
CH 1
SIG
CH 2
SHOR
T
LED
SHOR
T
DETECT
METER
DRIVE
TO
CH 2
MUTE
OL –3 –6 –9 –20 SIG
CH 2
SIG
SIG
(T
O CH 1
METER DRIVE)
SIG
(T
O CH 2
METER DRIVE)
PD's LEASH
HO
T
LED
COLD
LED
TEMP
SENSOR
(ON HEA
TSINK)
TO
CH 1
AND CH 2
MUTE
CH 1 AMP OUT
CH 2 AMP OUT
CH 1 MUTE
CH 2 MUTE
60ºC
DETECT
OR
FA
N
SPEED
CONTR
OL
HI DCV
LO
DCV
CH 1
MUTE
CH 2
MUTE
P
OWER
SWIT
CH
TO
CH 1
AND CH 2
MUTE
THERMAL
PR
O
TECT
THR
U
(XLR
-M)
CH 2
B
ALANCED
LINE INPUT
(T
R
S
)
CH 2
B
ALANCED
LINE INPUT
(XLR
-F)
THR
U
(XLR
-M)
80ºC MUTE
55ºC UNMUTE
FA
N
TO
HUSKY
S
TADIUM
1/4" T
S
J
A
CK
M•1200 only
1/4" T
S
J
A
CK
M•1200 only
OL
–3
–6
–9
–20
–3
–6
–9
–20
SIG
OL
SIG
CH
1
30
28
26
20
22
18
24
16
14
8
0 0
1.23v (+4dBu)
SENSITIVITY
GAIN/dB
CH
2
PROTECT
COLD
HOT
SHORT
TEMP STATUS
INTERNAL STATUS
CH
1
CH
2
CH
1& 2
ON
OFF
POWER
3v
2v
1v
30
28
26
20
22
18
24
16
14
8
0 0
1.23v (+4dBu)
SENSITIVITY
GAIN/dB
3v
2v
1v
PROFESSIONAL POWER AMPLIFIER
FULL SYMMETRY DUAL DIFFERENTIAL HIGH CURRENT DESIGN
19.00" (48.3cm)
17.25" (43.8cm)
15.25" (38.7cm)
3.50"
(8.9cm)
2U
16.25" (41.3cm)
M•1200/1400
WEIGHT
36 lbs.
(16.3 kg)
1.25"
(3.2cm)
Built-in subwoofer crossover.
The amplifier has a sub-
woofer mode that allows you
to turn on the built-in sub-
woofer crossover. When
activated, the signals appear-
ing at the left and right inputs
are summed, directed to a
low-pass filter, and routed
to both output stages. A
switch selects the cutoff fre-
quency of the filter at either
63Hz or 125Hz, and the ampli-
fier can be set to either mono
or bridge mode of operation.
Built-in constant directivity
horn compensation.
When a compression driver
is attached to a constant
directivity (CD) horn, it requires
a certain amount of high-
