Crown 1200, 2401, 2400 Rear Panel Facilities Power Cord, Stereo/Mono Modes Switch, MT-XLR Module

Micro-Tech Series Power Amplifiers

4 Operation

4.2.2 Rear Panel Facilities

F. Power Cord

All units are shipped with an approprate plug and cord for the required AC voltage.

G. Stereo/Mono Modes Switch

•Use Stereo mode for normal two-channel oper- ation.

•Use Bridge-Mono mode to drive a single chan- nel with a load impedance of at least 4 ohms.

•Use Parallel-Mono mode to drive a single channel with a load impedance less than 4 ohms.

Important: Turn off the amplifier before changing the Stereo/Mono modes switch.

H. Reset Switches (Micro-Tech 2400 only)

The Micro-Tech 2400 has two push-button reset swiches on the back panel that are used to reset the circuit breakers for the high-voltage power supplies. Refer to Section 5.1.5 in the rare event of a tripped breaker.

I. MT-XLR Module

This module provides two balanced XLR inputs. Because the MT-XLR connectors are in parallel with the amplifier’s built-in phone connectors, an input signal fed to either input can be fed to another amplifier from the unused connector for that chan- nel. If you prefer to use barrier block inputs instead, order the MT-BB accessory (see Section 5.2).

Input Sensitivity Switch

The three-position input sensitivity switch (Figure 4.2) is located inside the amplifier behind the MT- XLR module (I). See Section 3.7 for details.

J. Level Controls

Used to set the amplifier's output levels. These con- trols are on the back panel to prevent tampering. Be sure to turn down the Channel-2 level control (fully counterclockwise) when operating in Bridge-Mono or Parallel-Mono mode.

K. Balanced Phone Jack Inputs

A balanced ¼-inch phone jack input is provided for each channel. The jacks may be used with either

balanced (tip, ring and sleeve) or unbalanced (tip and sleeve) lines (refer to Figure 3.5). Balanced XLR ijnputs for each channel are provided with the MT-XLR module. Barrier-block input connectors are available with the MT-BB accessory (see Section 5.2.2). Caution: Do not use the Channel-2 input in either mono mode.

L. Ground Lift Switch

Used to isolate the phone jack signal grounds from the AC power (chassis) ground. Moving the switch to the "lift" position helps prevent the hum associ- ated with ground loops. Sliding the switch to the left isolates or "lifts" the grounds by placing an imped- ance between the sleeve of each phone jack and the AC ground.

M. Output Jacks

A pair of versatile binding posts is provided for out- put connection to each channel. Loudspeakers can be easily connected using banana plugs, spade lugs or bare wire (European models do not accept banana plugs). See Section 3.5.

MODEL: MICRO-TECH 2400 SERIES AC VOLTS: 120 AMPS: 17 60 Hz

MAXIMUM OUTPUT: 900 WATTS

PER CHANNEL INTO 2 OHMS AT 1 KHz WITH NO MORE THAN 0.1% THD.

REG. U.S. PAT. OFF.

4,330,809

4,611,180

PUSH TO RESET

	STEREO
PARALLEL	BRIDGE
MONO	MONO

CAUTION: TURN OFF AMPLIFIER BEFORE CHANGING THIS SWITCH!

CAUTION:

THIS COVER IS NECESSARY FOR

EFFICIENT COOLING OF THE AMPLIFIER.

REMOVE ONLY TO ACCESS GAIN SWITCH.

THIS AMPLIFIER IS EQUIPPED WITH SELECTABLE INPUT SENSITIVITY. REMOVE COVER PLATE (ABOVE) TO ACCESS SENSITIVITY SWITCH.

		6		CH-2				CH-1	6
	5		7					5		7
	4			8				4			8
	3			9				3			9
BALANCED	2			10	INPUT GROUND LIFT			2			10	UNBALANCED
INPUT WIRING	1			11				1			11	INPUT WIRING
+ TIP	0		12	INPUT	LIFT		INPUT	0		12		+ TIP
– RING	GAIN							GAIN
GND SLEEVE					(AFFECTS PHONE	INPUTS ONLY.)	(MONO)					GND SLEEVE

	BRIDGE-MONO WIRING
	–	1	TURN AMPLIFIER OFF.
		2	SET STEREO/MONO
OUTPUTS	+		SWITCH TO
			BRIDGE-MONO.

CLASS 1	3 OUTPUT ACROSS
	RED TERMINALS
OUTPUT
	ONLY. (CH-1
WIRING	IS POSITIVE.)
REQUIRED.

CH-2	CH-1	PARALLEL-MONO WIRING
		+	1	TURN AMPLIFIER OFF.
WARNING: TO REDUCE THE RISK OF FIRE OR			2	SET STEREO/MONO
		–		SWITCH TO
ELECTRIC SHOCK DO NOT EXPOSE THIS EQUIPMENT				PARALLEL-MONO.
TO RAIN OR MOISTURE.

	3	ADD JUMPER (14
		GAGE OR LARGER)
	® INTERNATIONAL, INC.	ACROSS RED
		TERMINALS.
ELECTRONIC EQUIPMENT
ELKHART, IN 46517	4	OUTPUT ACROSS CH-1
MADE IN U.S.A.	0000	TERMINALS ONLY.
SERIAL NUMBER	000000

F G H I J K L K JM M

Figure 4.2 Rear Panel Connectors and Controls

page 12 Operation Manual