Front Facilities Behind The Filter Grille - Crown Macro-Tech 5002VZ Reference Manual

Macro-Tech 5002VZ Power Amplifier
mode for each power supply. The switches are located
behind the top dust filter about 1.75 inches (4.5 cm)
behind the front panel. Always turn off the power be-
fore changing either switch. To access the VZ mode
switches, remove the top dust filter and reach upward
through the grille opening with a long narrow noncon-
ductive object like a plastic pen. The switches are easy
to locate with the aid of a flashlight. The switch for Chan-
nel 1 is located to the left side of the amplifier, while the
switch for Channel 2 is located to the right.
From left to right, the four switch settings are VZ-ODEP,
Lock Low, VZ and VZ (the third and fourth switch posi-
tions are identical). The first switch position sets the
power supply to the VZ-ODEP switching mode, which
is the default setting from the factory. The VZ-ODEP
mode automatically shifts between high-current and
high-voltage modes as needed, except when ODEP
actively limits output drive, in which case the power sup-
ply is locked in its high-current mode. The second
switch position is called "Lock Low." It locks the power
supply in high-current mode so the amplifier will always
be ready to deliver maximum current to low-impedance
loads. The third and fourth switch positions set the
power supply to standard VZ mode. Standard VZ mode
automatically switches between high-current and high-
voltage modes as needed, but is not affected by ODEP
(see Section 4.4).
I. Stereo/Mono Switch
This switch is used to select one of three output modes.
Stereo mode is used for normal two-channel operation,
Bridge-Mono mode is used to drive a single channel
with a load impedance of at least 4 ohms, and Parallel-
Mono mode is used to drive a single channel with a
load impedance less than 4 ohms. WARNING: The
Reference Manual
Fig. 2.2 Front Facilities behind the Filter Grille
amplifier should be off for at least 10 seconds be-
fore changing this switch (see Section 3.3).
J. Compressor Switches
A three-position back panel switch is provided to con-
trol each channel's "error-driven" input compressor. At-
tack and release times can be set to either "fast" or
"slow," or compression can be turned off for output clip-
ping errors. The "fast" setting yields a 4-millisecond at-
tack time and 300-millisecond release time. The "slow"
setting yields a 12-millisecond attack and 600-millisec-
ond release (see Section 4.4).
K. Loudspeaker Offset Integration Switches
Each channel has a two-position back panel on/off
switch used to control the Loudspeaker Offset Integra-
tion (LOI) circuitry. LOI compensates for asymmetrical
audio waveforms that cause off-center woofer cone
movement (see Sections 3.3.4, 3.3.5 and 4.4).
L. Input Sensitivity Switches
These three-position back panel switches are used to
select the input sensitivity for each channel. Available
settings include 0.775 volts or 1.4 volts for standard
1 kHz output power, or a 26 dB voltage gain (see Sec-
tion 4.4).
M. Power Cord
Units configured for 100 to 120 VAC have a 10-AWG,
30-amp line cord, while units set up for 200 to 240 VAC
have a 12-AWG, 20-amp line cord. North American
units configured for 120 VAC, 60 Hz power are shipped
with a grounded 125-volt, 30-amp NEMA TT30P plug;
units shipped outside North America are provided with-
out a plug. See Sections 3.4 and 7 for AC requirements.
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