Operation Manual
I-Tech HD DriveCore Series Power Amplifiers
page 14
I-Tech HD DriveCore Series Power Amplifiers
Operation Manual
page 15
6.2 Startup Procedure
When first turning on your amplifier, follow the procedures in the
Quick-Start Guide on page 4 (stereo) or page 5 (bridge-mono).
If you ever need to make any wiring or installation changes, don’t for get
to disconnect the power cord.
For help with determining your system’s optimum gain structure
(sig nal levels) please refer to the Crown
Amplifier Application Guide
,
available online at www.crownaudio.com.
6.3 Precautions
Your amplifier is protected from internal and external faults, but you
should still take the following precautions for optimum performance
and safety:
1. Before use, your amplifier first must be configured for proper
operation, including input and output wiring hookup. Improper
wiring can result in serious operating difficulties. For information
on wiring and configuration, please consult the Setup section of
this manual or, for advanced setup techniques, consult Crown’s
Amplifier Application Guide
available online at
www.crownaudio.com.
6 Operation
6.1 Protecting Your Speakers
It’s wise to avoid clipping amplifier signals at the input and output. Not
only does clipping sound bad, it can damage loudspeakers. To prevent
clipping, use System Architect software’s Level Max suite to enable or
display the peak voltage limiter and average power limiter in your
amplifier’s built-in DSP. That way, no matter how strong a signal your
mixer produces, the amplifier output will not clip. Set the limiter
threshold so that at full level no components in the audio signal chain
are clipping, the amplifier input and output is not clipping, and the
attached loudspeakers at properly protected according to the mnfg’s
rec’d specifications.
Also, avoid sending strong subsonic signals to the amplifier.
High-level, low-frequency signals from breath pops or dropped
micro phones can blow out drivers. To prevent subsonic signals, use
one of these methods:
• Insert a highpass filter between mixer output and amplifier input (or
between mixer and limiter).
• Use the I-Tech’s onboard DSP to set up a highpass filters.
• Switch in highpass filters at your mixer. Set the filter to as high a
fre quency as possible that does not affect your program. For example,
try 35 Hz for music and 75 Hz for speech. On each mixer input channel,
set the filter frequency just below the lowest fundamental frequency of
that channel’s instrument.
• Note: An amplifier reproduces the signal present on the input.
Therefore, if you send clipped or squared wave signals to the input, it
will recreate this on the output possibly damaging your loudspeakers.
2. Use care when making connections, selecting signal sources and
controlling the output level. The load you save may be your own!
3. Do not short the ground lead of an output cable to the input signal
ground. This may form a ground loop and cause oscillations.
4. WARNING: Never connect the output to a power supply,
battery or power main. Electrical shock may result.
5. Tampering with the circuitry, or making unauthorized circuit
changes may be hazardous and invalidates all agency listings.
6. Do not operate the amplifier with the red Clip LEDs constantly
flashing.
7. Do not overdrive the mixer, which will cause clipped signal to be
sent to the amplifier. Such signals will be reproduced with extreme
accuracy, and loudspeaker damage may result.
8. Do not operate the amplifier with less than the rated load
imped ance. Due to the amplifier’s output protection, such a
configura tion may result in premature clipping and speaker
damage.
9. CAUTION – SHOCK HAZARD: Potentially lethal voltages
exist at the output connectors when the amplifier is
turned on and is passing a signal.
Remember: Crown is not liable for damage that results from
overdriv ing other system components.
6 Operation
Figure 6.1 Front Panel Controls and Indicators
6.4 Front Panel Controls and Indicators
Many of these functions can be disabled using
Blackout Mode (a selection in the Advanced
Menu, Section 7.2).
A. Cooling Vents
Front-to-rear forced airflow through foam dust filter
B. LCD Display Screen
Integrated 4.3” color LCD with backlight, displays
amplifier settings.
The LCD Display Screen and its controls let the user
adjust the amplifier’s attenuation and muting,
con figure the amp, set up and view error monitoring
(such as temperature and load supervision), and
recall DSP presets.
C. Power Switch
Push-on/push-off switch glows green when AC
power is present at the power cord and the amplifier
circuit breaker is in the “on” position.
D. USB 2.0 Connector
Accepts a USB drive to transfer presets, device files,
and update firmware from the drive to the amplifier
DSP, and vice versa.
E. Fault Indicator
Red LED, one per channel, flashes when the
ampli fier output channel has stopped operating.
Usually this means that the amplifier must be
serviced.
F. Thermal Indicator
Red LED, one per channel, illuminates when the
channel has shut down due to thermal stress or
overload.
G. Clip Indicator
Red LED, one per channel, illuminates when the
channel’s output signal reaches the onset of audible
clipping. The Clip Indicator also will illuminate
dur ing Thermal Level Control (TLC) limiting. The
Clip Indicator can be turned off during Blackout
mode.
H. Level Control (Encoder)
Speed-sensitive, 0.5 dB steps, range 0 to –100 dB.
This knob affect the Channel 1-4 output levels. Also
Menu items and adjust parameter values that are
displayed on the LCD control screen.
I. Menu/Exit Button
“Menu” enters the main menu. “Exit” leaves the
menu.
J. Prev Button
Selects the previous item in the menu.
K. Next
Button
Selects the next item in the menu.
L. Signal Indicators
These can be disabled during Blackout mode. Three
green LEDS per channel indicate the ampli fier’s
input and output signal levels. From top to bot tom
the LEDs are
–10 dB
: amplifier output is 10 dB below clipping.
–20 dB:
amplifier output is 20 dB below clipping.
Signal:
selected input signal is above –40 dBu.
M. Ready Indicator
Green LED, one per channel, illuminates when the
channel is initialized and ready to produce audio
out put.
N. Power Indicator
Blue LED indicates amplifier has been turned on and
AC power is available. The LED will flash when the AC
line voltage is 15% above or below the nominal rated
range. This indicator can be turned off in Blackout
mode.
O. Data Indicator
Yellow LED indicates network data activity. Data
indicator flashes only when the amplifier is polled for
data, or is polled to see whether it is online. This
indicator can be turned off in Blackout mode.
P. Bridge Mode Indicator
Yellow LED illuminates when the amplifier is set to
Bridge-Mono mode.
