Crown Macro-Tech MA-1200 Reference Manual page 28

Stereo/Mono: A three-position back panel switch used to
select Stereo, Bridge-Mono or Parallel-Mono mode.
Sensitivity: A three-position switch inside the PIP compart-
ment used to select the input sensitivity for both channels:
0.775 volts or 1.4 volts for standard 1 kHz power, or a 26 dB
voltage gain.
Ground Lift: A two-position back panel switch for isolating
the phone jack input grounds from the AC ground.
Reset (Macro-Tech 2400 only): A back panel push button
for each channel used to reset the circuit breaker that pro-
tects each power supply.
Indicators
Enable: This amber front panel indicator shows the on/off
status of the low-voltage power supply.
Signal/IOC: Each channel has a green front panel indicator
that flashes to show amplifier output. If a channel's output
waveform differs from its input by 0.05% or more, the indica-
tor flashes brightly to show distortion. This function provides
proof of distortion-free performance . In Parallel-Mono mode,
the Channel 2 light stays on (see Section 4.2).
ODEP: Each channel has an amber front panel indicator that
shows thermal-dynamic energy reserve. Normally, each
ODEP indicator is lit to show available reserve energy. In the
rare event that a channel has no reserve, its indicator will dim
in proportion to ODEP limiting. An ODEP indicator may also
turn off under other conditions (see Section 4.2).
Input/Output
Input Connector: Two balanced
back panel and two balanced three-pin female XLR connec-
tors on the factory-installed P.I.P
mation on optional PIP modules).
Input Impedance: Nominally 20 k ohms, balanced. Nomi-
nally 10 k ohms, unbalanced.
Input Sensitivity: Settings include 0.775 volts or 1.4 volts for
standard 1 kHz power, or a 26 dB voltage gain (see Section
4.4 for more information).
Output Connectors: Two sets of color-coded 5-way binding
posts (for banana plugs, spade lugs or bare wire).
Output Impedance: Less than 10 milliohms in series with
less than 2 microhenries (see Figure 6.9).
DC Output Offset: (Shorted input) ±10 millivolts.
Output Signal
Stereo: Unbalanced, two-channel.
Bridge-Mono: Balanced, single-channel. Channel 1 controls
are active; Channel 2 should not be used.
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1
/ -inch phone jacks on the
4
. - FX (see Section 8 for infor-
Macro-Tech 600/1200/2400 Power Amplifiers
Parallel-Mono: Unbalanced, single-channel. Channel 1
controls are active; Channel 2 controls are bypassed.
Protection
Macro-Tech amplifiers are protected against shorted,
open or mismatched loads; overloaded power supplies;
excessive temperature, chain destruction phenomena,
input overload damage and high-frequency blowups.
They also protect loudspeakers from input/output DC and
turn-on/turn-off transients.
If unreasonable operating conditions occur, the patented
ODEP circuitry will proportionally limit the drive level to
protect the output transistor stages, particularly in the case
of elevated temperature. Transformer overheating will re-
sult in a temporary shutdown of the affected channel;
when it has cooled to a safe temperature, the transformer
will automatically reset itself. Controlled slew-rate voltage
amplifiers prevent RF burnouts. And input overload pro-
tection is provided by current-limiting resistance at the in-
put. Refer to Section 4.3.
Turn On: Four-second delay with no dangerous tran-
sients. Contact Crown's Technical Support Group to
change the turn-on delay time.
Construction
Steel chassis with durable black finish, aluminum front
panel with Lexan overlay, and specially designed flow-
through ventilation from front to side panels.
Cooling: Internal heat sinks with forced-air cooling for
rapid, uniform heat dissipation.
Dimensions: Standard 19-inch (48.3-cm) rack mount
width (EIA RS-310-B), 3.5-inch (8.9-cm) height, 16 inch
(40.6-cm) depth behind the mounting surface and 2.5-
inch (6.3-cm) protrusion in front of the mounting surface.
Approximate Weight: Center of gravity is 6 inches
(15.2 cm) behind front mounting surface.
120 VAC, 60 Hz Units:
Macro-Tech 600 : 39 pounds, 9 ounces (17.9 kg) net;
44 pounds (19.9 kg) shipping weight.
Macro-Tech 1200 : 44 pounds, 1 ounce (20.0 kg) net;
47 pounds (21.3 kg) shipping weight.
Macro-Tech 2400 : 51 pounds, 12 ounces (23.5 kg) net;
65 pounds (29.5 kg) shipping weight.
International Units:
Macro-Tech 600 : 41 pounds, 15 ounces (19.0 kg) net;
46 pounds (20.9 kg) shipping weight.
Macro-Tech 1200 : 42 pounds, 12 ounces (19.4 kg) net;
46 pounds, 13 ounces (21.3 kg) shipping weight.
Macro-Tech 2400 : 48 pounds, 15 ounces (22.2 kg) net;
57 pounds, 6 ounces (26.0 kg) shipping weight.
Reference Manual