Technical information
Macro-Tech 3600VZ Power Amplifier
Page 19
4 Operation
4.1 Precautions
Although the
Macro-Tech 3600VZ
is protected from ex-
ternal faults, the following precautions should be fol-
lowed for safety and optimum operation:
1. There are important differences among the Ste-
reo, Bridge-Mono and Parallel-Mono operating
modes (see Section 3.3).
2. WARNING: Do not change the position of the
Stereo/Mono switch unless the amplifier is
first turned off.
3. CAUTION: In Parallel-Mono mode, a jumper
is used between the Channel 1 and Channel
2 red binding posts (amplifier outputs). Be
sure to remove this jumper for Bridge-Mono
or Stereo mode; otherwise inefficient opera-
tion, high distortion and excessive heating
will occur. Check the Stereo/Mono switch on
the back panel for proper position.
4. Turn the amplifier off and unplug it from the
AC mains before removing a
P.I.P.
card.
5. Use care when making connections, selecting
signal sources and controlling the output level.
The load you save may be your own.
6. Do not short the ground lead of an output cable
to the input signal ground. This may form a
ground loop and cause oscillations.
7. Operate the amplifier from AC mains of not
more than 10% variation above or below the se-
lected line voltage and only the specified line
frequency.
8. Never connect the output to a power supply
output, battery or power main.
9. Tampering in the circuit by unqualified person-
nel, or making unauthorized circuit changes
may be extremely dangerous and may invali-
date the warranty.
Remember: Crown is not liable for damage that results
from overdriving components in your system.
4.2 Indicators
The front panel has several helpful LED (light emitting
diode) indicators.
The amber Enable indicator is provided to show the
amplifier has been turned on (or enabled) and that the
low-voltage power supply is working. It does not indi-
cate the high
voltage supply status. As a result, disrup-
tion of the high
voltage supplies has no effect on the
LEVEL LEVEL
ON
OF
F
30
27
24
21
18
15
12
9
6
3
0
ENABLECH1 CH2
ODEP
30
27
24
21
9
6
3
0
SIGNAL
/
IOC
18
15
12
Enable indicator. This means that in the improbable
event that one or both channels overheat and cause a
shut down of the high voltage power supply, the En-
able indicator will remain on. However, the Signal/
IOC
indicator lights to show that the output waveform does
not match the input.
The
ODEP
indicators provide a visual indication of the
operation of Crown’s patented Output Device Emula-
tion Protection (
ODEP
) circuitry. This circuitry protects
the amplifier output stages against heat damage by
proportionally limiting the drive level to the output
stages. This enables the amplifier to operate safely
even under severe operating conditions.
During normal operation, the
ODEP
indicators glow
brightly to indicate that the output stages are operating
within their thermal range (SOA - Safe Operating Area).
However, if an output stage begins to overheat, the
ODEP
circuitry proportionally limits the drive signal and
the LEDs dim. In the unlikely event that the amplifier
exceeds the operating limits,
ODEP
shuts down the
output stages and the indicators turn off. The indica-
tors also turn off if the power supplies are put in standby
mode.
Note: The high voltage power supplies will temporarily
go into standby mode if their transformers get too hot
or if there is DC or heavy common-mode current in the
output.
The green Signal/
IOC
indicators provide the triple
functions of Signal Presence, Distortion, and Input
Overload indicators. As signal presence indicators,
they flash with normal intensity in sync with the audio
outputs. As
IOC
(Input/Output Comparator) indicators,
they flash brightly if there is any difference between the
input and output signal waveforms greater than 0.05%.
Because transient distortion happens quickly, a 0.1
second “hold delay” keeps the indicators on long
enough to be easily noticed. This
IOC
function verifies
the amplifier’s performance. As input overload indica-
tors, they flash brightly with a 0.5 second hold delay
Fig. 4.1 Indicators