NHT A-20 System Connections Control Amplifier Input Section, Speaker Cable Connections

SYSTEM CONNECTIONS:

CAUTION: MAKE ALL CONNECTIONS WITH THE AC POWER OFF!

CAUTION: CONNECTING THE OUTPUT OF THE A-20 CONTROL AMPLIFIER TO ANY EQUIPMENT OTHER THAN THE A-20 OR C-20 MONITOR MAY CAUSE EQUIPMENT DAMAGE.

CONTROL AMPLIFIER INPUT SECTION:

The A-20 Control Amplifier accepts both balanced and unbalanced inputs on either XLR or 1/4” TRS connectors. These connectors are hardwired in parallel within the A-20 to allow for convenient equipment chaining, but only one signal source 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, keeping in mind that the A-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 CABLE CONNECTIONS:

The A-20 includes two 20’ special purpose cables to connect the Control amplifier to the Monitors. While these cables look similar to standard microphone cables, they are constructed with lower and more consistent conductor impedance. Portions of the A-20’s crossover circuitry are located in both the amplifier and speaker enclosures, and the cables supplied are an important part of this electrical network. This allows the speaker cables to function as a neutral and transparent component in the system. Replacing or extending the supplied cables with any other type will have a varying, and only partly predictable impact on the sound of the A-20. If your installation requires the use of alternative cables, you may consult the table listing our measurement data on a variety of cable types at www.vergenceaudio.com under the support section. Be sure they are wired as shown in Fig. 3a. These considerations aside, using the Vergence cables to connect the control amplifier is quite simple and straight forward. Both the amplifier and the monitors are marked with the appropriate “left” and “right” channels. Fit the XLR connectors into the corresponding connectors on the control amplifier and monitors until the connector locks.

WARNING: IF USING CABLES OTHER THAN THOSE SUPPLIED WITH THIS SYSTEM, BE SURE THAT NO CONDUCTIOR IS WIRED TO THE XLR CASING. FAILURE TO

DO SO MAY CONSTIT UTE A RISK OF ELECTRIC SHOCK.

A-20 Monitor	CAUTION
Right	RISK OF ELECTRIC SHOCK		RIGHT				LEFT	NHTPro
	DO NOT OPEN							MODEL A-20 CONTROL AMPLIFIER.
	WARNING: SHOCK HAZARD-DO NOT OPEN.							SERIAL NO:	A20-A-10001
	AVIS: RISQUE DU CHOC ELECTRONIQUE-
	NE PAS OUVRIR.
	CAUTION:							NHTPro
					INPUT			BENICIA, CALIFORNIA, U.S.A.
	FOR CONTINUED PROTECTION AGAINST
										G1
	RISK OF FIRE REPLACE ONLY WITH SAME							MADE IN TAIWAN
	TYPE 250V FUSE.				2	PIN SIGNAL
					3
INPUT VOLTAGE	FUSE TYPE:				1	1	GND
			2		1
	T9A 250V FOR 110/120V.					2	+
			LISTED				_
	T5A 250V FOR 220/240V.	UL		3		3
			AUDIO EQUIP	XLR	TRS
	50/60 Hz - 950W

A-20Monitor

Left

CAUTION:

CONNECTING OUTPUTS TO ANY PRODUCT OTHER THAN A-20 or

C-20 MONITORS MAY RESULT IN SEVERE EQUIPMENT DAMAGE.

Fig. 4 A-20 Control Amplifier Rear Panel