Page 10
Macro-Tech 5002VZ
Power Amplifier
Reference Manual
Fig. 2.1 Front Facilities
2 Facilities
A. Dust Filters
The dust filters remove large particles from air drawn in
by the cooling fans. Check the filters regularly to pre-
vent clogging (see Sections 3.2 and 4.5).
B. Level Controls
The output level for each channel is set with these con-
venient front panel level controls. Each control has
31 detents for precise adjustment (see Section 4.4). A
security option is also available to prevent tampering
(see Section 8.2).
C.
I
Load
/
I
Limit
Indicators
The flow of current to the loudspeakers (“load current”)
and the maximum current limit of the amplifier (“limit
current”) are monitored by these two-color front panel
indicators. Normally, the
I
Load
/
I
Limit
indicators glow
green to show that load current is flowing. They turn off
when there is no significant load current. This happens
when there is no input signal, the input signal is at an
extremely low level, or there are no loads connected to
the amplifier’s outputs. They turn red if the amplifier has
reached its maximum output current capacity.
The
I
Load
/
I
Limit
indicators are very useful when loading
the amplifier for maximum output. Just continue to connect
additional loudspeakers in parallel with each output until
the
I
Load
/
I
Limit
indicator turns red under normal operating
conditions. The optimum load is achieved just before the
indicator turns red (see Section 4.2).
D. Signal/
IOC Indicators
These green multifunction indicators show both signal
presence and distortion for each channel. As signal
presence indicators, they flash synchronously with the
amplifier’s audio output. As IOC (Input/Output Com-
parator) indicators, they flash brightly with a 0.1 second
hold delay if there is a difference of 0.05% or more be-
tween the input and output audio waveforms. IOC “er-
rors” occur most commonly when a large input signal
causes an input overload or output clipping. The IOC
function is also provided as
proof of distortion-free per-
formance (see Section 4.2).
E.
ODEP Indicators
During normal operation of the ODEP (Output Device
Emulation Protection) circuitry, these amber indicators
glow brightly to show the presence of reserve thermal-
dynamic energy. They dim proportionally as energy re-
serves decrease. In the rare event that energy reserves
are depleted, the indicators turn off and ODEP propor-
tionally limits output drive so the amplifier can safely
continue operating even under severe conditions.
These indicators also help to identify more unusual op-
erating conditions (see Section 4.2).
F. Enable Indicator
This indicator lights when the amplifier has been turned
on (enabled) and has AC power (see Section 4.2).
G. Enable Switch
This push button is used to turn the amplifier on and off.
When turned on, the output is muted for about four sec-
onds to protect your system from start-up transients.
This is why a power sequencer is rarely needed for mul-
tiple units. (The length of the turn-on delay can be
changed. Contact Crown’s Technical Support Group for
details.)
H. VZ Mode Switches
A four-position switch is used to control the switching
