Page 8
Reference Manual
Macro-Tech
®
24x6 & 36x12 Power Amplifiers
Fig. 2.1 Front Facilities
2 Facilities
A. Dust Filter
The dust filters remove large particles from the air at the
air intake. Check the filters regularly to be sure they don’t
become clogged. The filter elements can be easily re-
moved for cleaning by gently pulling them away from
the front panel. See Section 3.2 and 4.5.
B. Level Controls
The level for each channel is set with these convenient
controls mounted on the front panel. Each level control
has 31 detents for precise adjustment (see Section 4.4).
A security option is available to prevent tampering (see
Section 8.2).
C. Signal / IOC Indicators
These green multifunction indicators show signal pres-
ence and distortion for each channel. As signal pres-
ence indicators, they flash synchronously with the
output audio signals to show their presence. As IOC
(Input/Output Comparator) indicators, they flash
brightly with a 0.1 second hold delay if there is a differ-
ence of 0.05% or more between the input and output
signal waveforms. This provides
proof of distortion-free
performance. Another IOC function is to indicate input
overload. If an input signal is too large, the indicator for
the affected channel flashes brightly with a 0.5 second
hold delay to show clipping distortion.
D. 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 can also help identify more unusual
operating conditions (see Section 4.2).
E. Enable Indicator
This indicator lights when the amplifier has been “en-
abled” or turned on and AC power is present (see Sec-
tion 4.2).
F. Enable Switch
This push button is used to turn the amplifier on and off.
When turned on, the output is muted for approximately
four seconds to protect your system from start-up tran-
sients. (This delay can be changed. Contact Crown’s
Technical Support Group for details.)
G. Power Cord
An appropriate power cord is provided. 120 VAC, 60
Hz units have a 20-amp (12 AWG) line cord with a
grounded NEMA 5-15P plug. See Section 7 for AC
power usage.
