NHT M-20 owner manual Typical installation

SYSTEM CONNECTIONS:

CAUTION: MAKE ALL CONNECTIONS WITH THE AC POWER TURNED OFF!

POWER CONNECTIONS/FUSE:

The power cord receptacle contains a spare fuse located within the power connector. To get at the fuse, remove the power cord and use a small flat head screwdriver to access the fuse compartment. When replacing the fuse with a spare, use only a fuse of the same current rating. Located next to the power cord receptacle is a voltage selector, preset at the factory for the destination country; the power cord supplied is appropriate for that voltage. Confirm the voltage selector setting before powering up the system.

CONTROL AMPLIFIER INPUT SECTION:

The M-20 Control Amplifier accepts both balanced and unbalanced inputs on either XLR or 1/4” TRS connectors. These connectors are connected in parallel within the M-20 to allow for convenient equipment chaining, but only one input should be physically connected to the unit at any time. Figure 3a shows the proper wiring schematic for each type of connector. Since there are so many different connector types and signal levels employed by source equipment, some experimentation may be necessary. Keep in mind that the M-20 can accept a wide range of signals and has an input sensitivity control on the front panel.

		2	PIN SIGNAL		SOURCE
		3
		1	1	GND	+ (SIGNAL)
2	1		2	+
					- (GND)
				_
3			3
XLR		TRS

Shield

A-20 INPUT

2

3

1

Fig. 3a Balanced Wiring Diagram Fig. 3b Unbalanced Wiring Diagram

SPEAKER CONNECTIONS:

The M-20 includes a 20’ special purpose cable to connect the Control Amplifier to the Monitor. While this cable looks similar to a standard microphone cable, it is constructed with lower and more consistent conductor impedance. Portions of the M-20’s crossover circuitry are located in both the amplifier and speaker enclosures, and the cable supplied is an important part of this electrical network. This allows the speaker cable to function as a neutral and transparent component in the system. Replacing or extending the supplied cable with any other type will have a varying and unpredictable impact on the sound. If your installation requires the use of alternative cables, you may consult the Cable Measurement Data Chart on our website. Be sure they are wired as shown in Fig. 3a.

Using the included cable to connect the M-20 Monitor to the Control Amplifier is quite simple and straightforward: fit the XLR connectors into the corresponding connectors on the Control Amplifier and Monitor until the connector locks.

WARNING: IF USING CABLES OTHER THAN THOSE SUPPLIED WITH THIS SYSTEM, BE SURE THAT NO CONDUCTOR IS WIRED TO THE XLR CASING. FAILURE TO DO SO MAY CONSTITUTE A RISK OF ELECTRIC SHOCK.

FUSE TYPE:

T9A 250V FOR 110/120V. T5A 250V FOR 220/240V.

50/60Hz - 950W

115

INPUT VOLTAGE

	Fig. 4 Typical installation
CAUTION	M-20 MONITOR CONTROL AMPLIFIER.
RISK OF ELECTRIC SHOCK
	INPUT
DO NOT OPEN	SERIAL NO:
WARNING: SHOCK HAZARD - DO NOT OPEN.	NHTPro
AVIS: RISQUE DU CHOC ELECTRONIQUE -
NE PAS OUVRIR.	BENICIA, CALIFORNIA, U.S.A.
	MADE IN CHINA G1

CAUTION: FOR CONTINUED PROTECTION AGAINST

FIRE REPLACE ONLY WITH SAME TYPE 250V FUSE.

M-20

MONITOR

CAUTION: CONNECTING OUTPUT TO ANY PRODUCT OTHER THAN THE M-20 MONITOR MAY RESULT

IN SEVERE EQUIPMENT DAMAGE.

To AC outlet	Source	To monitor via
		supplied red cable