User manual NAD 912

[. . . ] COUNTER CLOCKWISE, viewed from the back panel). If this piece of equipment is to be used in a multiroom ouput of a NAD product, please ensure that before turning on the system for the first time, the Volume controls on any auxiliary amplifier ARE SET TO THE MINIMUM LEVEL. The multi-room output is not affected by the Volume or Tone controls (Treble, Bass) of the main system controls, so care must be taken to prevent auxiliary amplifiers being driven at full output level. [. . . ] (Suggestion: adjust the input level controls so that your preferred maximum sound levels usually occur at about 2 or 3 o'clock on the volume control. ) As an added benefit, this procedure suppresses any noise produced by the preamp's high-level circuitry (e. Any residual hum or hiss that does not go away when the Volume is turned down). Small errors in channel balance can dramatically degrade the apparent "depth" and "air" of the stereo image. Such balance errors may be due to normal production-line differences in speaker sensitivity, differences in the acoustic environment around the two speakers, and slightly different distances from your chair to each speaker. You can use the input-level controls to correct these fixed balance errors, freeing your preamplifier's balance control to correct balance errors in recordings. Switch the preamp to mono and sit in your normal listening location. Ideally the "phantom" central image should seem to be floating in mid-air midway between the left and right speakers. If it is located off-center, closer to one speaker, turn down the inputlevel control for that channel slightly in order to recenter the phantom mono image. Plug the AC line cord into a nearby wall outlet that provides the correct AC power line voltage, or into a switched convenience outlet on your preamp. Before making connections to the amplifier, make sure the POWER is switched OFF. Connect the signal cable from the preamplifier, surround decoder or other signal source to the inputs. If you want to use the 912 as a single 90-watt amplifier instead of a stereo 30 W/ch amp, see BRIDGING (Refer to item 6). This amplifier is equipped with special high-current binding-post speaker terminals to handle the highest peak power levels that may occur in the "bridged" Connections may be made in either of two ways. ] (1) Strip off a half-inch (1 cm) of insulation from each speaker wire. in each conductor , twist the thin strands of wire together. Unscrew the knob, insert the bare wire into the opening at the base of the binding post, and tighten the knob until it grasps the wire securely. Check to be sure that no loose strand of wire is touching the chassis or an adjacent terminal. [. . . ] CAUTION: In the bridged mode, wires must be connected directly from the amplifier to the speakers, not to a speaker switch, headphone adapter, or any other device that shares a common ground between channels. NOTE -- If you are using two pairs of speakers on one channel, or if you are in the bridged mode, we recommend that the speakers have a nominal impedance of 8 or more. When an amplifier is driven beyond its specified power output it normally produces "hard clipping" of the signal with harsh distortion and power-supply buzz as the output transistors saturate. [. . . ]