User manual NAD S200

[. . . ] Warning: To reduce the risk of fire or electric shock, do not expose this unit to rain or moisture. The lightning flash with an arrowhead symbol within an equilateral triangle, is intended to alert the user to the presence of uninsulated "dangerous voltage" within the product's enclosure that may be of sufficient magnitude to constitute a risk of electric shock to persons. the exclamation point within an equilateral triangle is intended to alert the user to the presence of important operating and maintenance (servicing) instructions in the literature accompanying the product. Do not place this unit on an unstable cart, stand or tripod, bracket or table. [. . . ] Always disconnect the AC Mains cable plug from the live wall socket first, before disconnecting the cable from the S200 Mains input socket. If you must use an extension cord, select a heavy-duty cord of the type used for large electrical appliances. do not connect the amplifier's Mains cable to the accessory AC outlets on a preamplifier. Such convenience outlets are not designed to supply the high power levels, up to 800 watts, that the S200 requires. If you wish to switch your entire audio system on and off at once, plug both the S200 and your preamplifier into a "power strip" containing several grounded AC outlets and a high-current on/off switch. CAUTION: Safety organisations recommend that the speaker terminals of a very powerful amplifier should be covered. Potentially dangerous voltages are present on these terminals when the amplifier is producing maximum power. For your protection and in order to comply with these regulations, we have chosen speaker terminals of the very highest quality for the NAD S200. These terminals are covered by plastic bushings which prevent the touching of metal parts. If your preamplifier has balanced XLR outputs, connect a threeconductor cable from your left channel preamplifier output to the left-channel XLR input on the S200, and set the BALANCE switch to BAL. If your audio dealer does not have the appropriate cables, purchase balanced "microphone" cables from a shop that sells professional recording equipment. The end of the cable that has a "male" XLR plug (with three metal pins) should be connected to the S200 amplifier. The end of the cable that has a "female" XLR socket (with three holes) should be connected to your preamplifier. An XLR plug is "keyed" so that it fits into the socket only one way. If there is a set-screw in the barrel of the plug, align it with the top of the connector. The three pins of an XLR type ("Cannon") connector are numbered. Pin 1 is the chassis earth (ground), to which the shield of a balanced-wire cable is connected. Stereo speakers must operate "in phase" with each other to produce a focused stereo image and to reinforce rather than cancel each other's output at low frequencies. an in-phase connection is assured if the red (positive) terminal on the amplifier is connected to the red (positive) terminal on the loudspeaker in each channel. If your speakers are easily moved, their phasing can easily be checked. Make the connections to both speakers, place the speakers face-toface only a few inches apart, play some music, and listen. Then swap the connection of the two wires at the back of ONE of the speakers, and listen again. [. . . ] An 8 ohm load looks like 4 ohms, a 4 ohm load looks like 2 ohms, and a pair of 4 ohm speakers operated in parallel will resemble a 1 ohm load. Driving paralleled low-impedance speakers to high levels will cause the amplifier to overheat and shut down, or may cause internal fuses to blow in order to protect the amplifier. In bridged mode you must connect only ONE loudspeaker per channel whose nominal impedance is 8 ohms or higher. This blue LED lights up when the S200 is switched on, and indicates the operating status of the amplifier as follows. [. . . ]