MACKIE FRSERIES M1400 - Manual (Page 2)

perature status LEDs shall
appear on the front panel,
one to indicate normal opera-
tion (COLD) and one to indi-
cate thermal protection (HOT).
7. PROTECTION FEATURES.
The amplifiers shall provide
delayed activation of the
outputs at turn-on. Each
channel shall have a short-
circuit protection circuit for
detecting excessive current
flow at the output that, when
activated, mutes the output
for four seconds. The short-
circuit protection shall con-
tinuously cycle on and off
until the shorted condition
is remedied. The amplifier
shall have a thermal protec-
tion circuit to protect the
power devices from over-
temperature operation. The
circuit shall activate when
the internal temperature
crosses the safe-operating
threshold and, when activated,
mute the outputs until the
internal temperature cools
to a safe-operating tempera-
ture, at which time the ampli-
fier shall resume normal
operation. The amplifier
shall have a fan to cool the
heat-producing internal
components. The fan shall
operate at two speeds, the
speed being determined by
the internal temperature and
the signal level present at
the output. The amplifier
shall have an SCR crowbar
circuit to protect the speak-
ers against a catastrophic
amplifier failure. The circuit
shall activate in the pres-
ence of continuous DC at
the speaker outputs, and
shall shut the amplifier
down by turning off the
high-voltage rails. 8. OUTPUT CONNECTIONS.
M•1200: Each channel shall
have heavy-duty 5-way bind-
ing post speaker output
connectors appearing on
the rear panel, with 3/4"
spacing for accommodating
standard double banana
plugs as well as spade lugs
or bare wires. Each channel
shall have a 1/4" TS phone
speaker output jack appearing
on the rear panel in parallel
with the binding post output.
M•1400: Each channel shall
have heavy-duty 5-way bind-
ing post speaker output
connectors appearing on
the rear panel, with 3/4"
spacing for accommodating
standard double banana
plugs (120V versions only)
as well as spade lugs or
bare wires. Each channel
shall have a Neutrik brand
Speakon
® speaker output
jack appearing on the rear
panel in parallel with the
binding post output.
9. AMP MODES. The ampli-
fier shall have a three-way
switch appearing on the
rear panel for selecting the
mode of operation, which
shall include stereo (two
channels in, two channels
out), mono (one channel
in, two channels out), and
bridge (one channel in, one
channel out bridged between
both speaker outputs).
10. OUTPUT APPLICATION.
The amplifier shall have a
three-way switch appearing
on the rear panel for selecting
between limiter on, limiter
off, and subwoofer mode.
The defeatable electronic
limiter circuit shall sense
the onset of clipping and
shall limit the input signal
and thereby prevent the
output from clipping. The
amplifiers shall have a two-
way switch appearing on the
rear panel for selecting be-
tween a 63Hz and 125Hz
low-pass cutoff frequency
when subwoofer mode is
selected.
11. LOW-CUT FILTER. Each
channel shall have a low-cut
filter with a variable frequency
control appearing on the
rear panel covering a range
of 10Hz (OFF) to 170Hz.
12. CONSTANT DIRECTIVITY
HORN EQ. Each channel
shall have a two-way switch
appearing on the rear panel
for selecting a constant
directivity horn equalization
circuit. When selected, this
circuit shall provide a 6dB
per octave high frequency
boost. The EQ shall have a
variable frequency control
appearing on the rear panel
covering a range of 2kHz to
6kHz. The 6kHz position
shall be called AIR.
13. PHYSICAL CONFIGU-
RATION. The amplifier shall
be rack-mountable with
rear support rails for extra
support, and shall have a
steel chassis frame painted
grey-black. The amplifier
shall be 19" wide, 3.5" tall
(2U) and 15.25" deep, and
shall weigh 36 pounds.
®