NAD 912 GB F D E P I S · OWNER'S MANUAL · MANUEL D'INSTALLATION · BEDIENUNGSANLEITUNG · MANUAL DEL USUARIO · MANUAL DO PROPRIETÁRIO · MANUALE DELLE ISTRUZIONI · BRUKSANVISNING WARNING:TO PREVENT FIRE OR ELECTRIC SHOCK, DO NOT EXPOSE THIS APPLIANCE TO RAIN OR MOISTURE Note to CATV system installer: This reminder is provided to call the CATV installer's attention to Article 820-40 of the NEC , which provides guidelines for proper grounding and, in particular, specifies that the cable should be connected to the grounding system of the building, as close to the point of cable entry as practical. CAUTION: TO PREVENT ELECTRIC SHOCK DO NOT USE THIS POLARISED PLUG WITH AN EXTENSION CORD RECEPTACLE OR OTHER OUTLET UNLESS THE BLADES CAN BE FULLY INSERTED TO PREVENT BLADE EXPOSURE. ATTENTION: POUR PREVENIR LES CHOCS ELECTRIQUES NE PAS UTILISER CETTE FICHE POLARISEE AVEC UN PROLONGATEUR, UNE PRISE DE COURANT OU UNE AUTRE SORTIE DE COURANT, SAUF SI LES LAMES PEUVENT ETRE INSEREES A FOND SANS EN LAISSER AUCUNE PARTIE A DECOUVERT. CAUTION RISK OF ELECTRIC SHOCK DO NOT OPEN CAUTION: TO REDUCE THE RISK OF ELECTRIC SHOCK, DO NOT REMOVE COVER (OR BACK). NO USER SEVICEABLE PARTS INSIDE. REFER SERVICING TO QUALIFIED SERVICE PERSONNEL. ATTENTION: RISQUE DE CHOC ELECTRIQUE NE PAS OUVRIR AFIN DEVITER UN CHOC ELECTRIQUE, ET LES CONSEQUENCES GRAVES QUI POURRAIENT EN RESULTER, TENTEZ PAS D'OUVRIR L'APPAREIL ET DE TOUCHER AUX COMPOSANTS INTERNES SANS LA PRESENCE D'UNE SERVICE PERSONNEL. The lightning flash with arrowhead, within an equilateral triangle is intended to alert the user of 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 of the presence of important operating and maintenance (servicing) instructions in the literature accompanying the appliance REAR PANEL CONNECTIONS (CH1 INPUT) NAD 2 FRONT PANEL CONTROLS Diagram 1. Figure 2. NAD 3 GB NAD 912 POWER AMPLIFIER 3. LINE OUTPUTS Each input has an accompanying line output which will pass the signal on to another amplifier input or other line-level device. The line outputs are buffered, so that a low impedance or short circuit placed across it will not affect the signal at the input. If the 912 is being used to amplify a remote pair of speakers, connect the system's preamplifier to the 912's inputs, then run a pair of cables from the 912's outputs to the inputs of the main stereo amplifier. (See Diagram #1). A NOTE ON INSTALLATION This unit may be installed on any sturdy, level surface. Since its power transformer generates a magnetic hum field of moderate strength, a turntable (especially one with a moving-coil pickup cartridge) should not be located near the amplifier. The amplifier requires ventilation. Do not obstruct the air outlet grilles on the top or bottom covers, and do not place the amplifier on a rug or other soft surface. Do not place the amplifier in an enclosed situation such as in a bookcase or in a cabinet. SAFETY WARNING: Please ensure that the Volume controls at the rear of this amplifier are set to minimum level (i.e. 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. WARNING TO UK USERS. If this appartus is not fitted with a UK three-pin plug, do not attempt to insert the attached plug into a UK mains socket. Instead, cut the plug from the mains lead and attach a fused UK three-pin plug using the following safety advice on wiring. IMPORTANT. The wires in this mains lead are coloured BLUE and BROWN; BLUE: NEUTRAL BROWN: LIVE The colours of these mains lead wires may not correspond with the coloured markings identifying the terminals in your plug. In this case the BROWN wire must be connected to the terminal which is marked L(ive) or coloured RED. The BLUE wire must be connected to the terminal marked N(eutral) or coloured BLACK. No connection should be made to the terminal marked E or coloured green or green and yellow 4. INPUT LEVEL The amplifier is equipped with separate input level controls for each channel. Before turning on the 912 for the first time, make sure all level controls are in their normal minimum (full-clockwise) power position. Under some circumstances, other settings may be useful for: (1). Level-matching. In a surround-sound or other multi-amplifier system, reduce some of the controls as necessary to balance the system with speakers of varying sensitivities. (2). Extended volume-control range. Many stereo systems have so much voltage gain that the speakers (or your ears) are over-driven at any volume-control setting higher than 11 or 12 o'clock. As a result you are confined to using only the lower half of the volume control's range, where adjustments are imprecise and where channel-balance errors tend to be greater. If all input-level controls are reduced, you can turn up your preamplifier's volume control, making effective use of most of its range. (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.g. any residual hum or hiss that does not go away when the Volume is turned down). (3) Balance correction. 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. Then restore the preamp to normal stereo operation. REAR PANEL CONNECTIONS 1. AC LINE CORD 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. 2. INPUTS The 912 has both inputs and outputs. 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). 5. SPEAKER CONNECTIONS 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" NAD 4 GB mode or with low-impedance loudspeakers. Connect the loudspeakers with heavy-duty (16-gauge or thicker) stranded wire. Connections may be made in either of two ways. [See Figure 2.] (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. (2) Install banana plugs on your speaker wires, and plug them into the end of each binding post. The terminals are separated by 3/4 inch (19mm), so they will accept dual-banana plugs. Connect the wires from the left-channel speaker to the CH 1 + and CH 1 - terminals and the wires from the right-channel speaker to the CH 2 + and CH 2 terminals. NOTE -- Stereo speakers must operate in phase with each other in order to produce a focused stereo image and to reinforce rather than cancel each other's output at low frequencies. When connecting speakers, take care that the red (positive) terminal on each loudspeaker is connected to the corresponding red (positive) terminal on the amplifier. SOFT CLIPPING circuit gently limits the output waveform and minimizes audible distortion when the amplifier is overdriven. We recommend that it be switched ON when playing music at levels that might exceed the amplifier's power capacity. FRONT PANEL 1. POWER Press this button to switch the amplifier on or off. A green LED above the power button illuminates when the power is on. 6. BRIDGING The two amplifiers within the Model 912 can be "bridged" to form a single amplifier of about three times the power per channel. To convert to bridged operation: (1) Switch the POWER off. (2) Disconnect any input and output cables. (3) Set the bridging switch to ON. (4) Select the cable from the speaker that is to be driven by the 912. Connect its "positive" conductor to the CH 1 + terminal and its "negative" conductor to the CH 2 + terminal (i.e. to the two red terminals). DO NOT connect any wires to the black terminals (CH 1 and CH 2 -). 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. (5) Connect the signal lead from the source chosen to be amplified by the bridging amplifier to the input socket of the CH 1 amplifier. (6) Turn the POWER on. 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. 7. SOFT CLIPPING 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. The NAD NAD 5 F AMPLIFICATEUR DE PUISSANCE NAD 912 dance faible ou un court circuit sur la sortie n'aura aucune influence sur le signal à l'entrée. Si le 912 est utilisé pour l'amplification d'une paire de haut-parleurs satellites, brancher le préamplificateur de la chaîne sur les entrées du 912, puis faire cheminer une paire de câbles depuis les sorties du 912 jusqu'aux entrées de l'amplificateur stéréophonique principal. (Cf. Schéma N° 1). NOTE CONCERNANT L'INSTALLATION Cet appareil peut être posé sur n'importe quelle surface robuste, à condition qu'elle soit plane et horizontale. Son transformateur de puissance génère un champ de ronflement magnétique de puissance moyenne, ce qui fait que l'amplificateur ne doit pas être placé près d'une platine tourne-disque (surtout si elle est équipée d'une cartouche pick-up électromagnétique). L'amplificateur a besoin de ventilation. Ne pas obstruer les grilles de sortie d'air sur les faces supérieure et inférieure, et ne pas poser l'amplificateur sur un tapis ou sur une quelconque surface molle. Ne pas placer l'amplificateur dans un endroit fermé (sur une étagère à livres ou dans un meuble, par exemple). AVERTISSEMENT DE SECURITE : Veiller à ce que les commandes de volume sonore à l'arrière de cet amplificateur soient réglées au niveau minimum (c'est à dire en butée ANTI-HORAIRE, vues depuis la face arrière). Si ce matériel doit être utilisé au sein d'une sortie multi-salles d'un produit NAD, faire bien attention, avant de mettre la chaîne sous tension pour la première fois, à ce que les commandes de volume sonore sur tout amplificateur auxiliaire soient REGLEES AU NIVEAU MINIMUM. La sortie multi-salles n'est pas affectée par les commandes de Volume Sonore et de Tonalité (Aigus, Graves) de la chaîne principale, et il faut donc faire attention afin de ne pas piloter les amplificateurs auxiliaires à leur niveau de sortie maximum. 4. NIVEAU D'ENTREE L'amplificateur est équipé de commandes de niveau d'entrée distinctes pour chaque voie. Avant de mettre le 912 sous tension pour la première fois, vérifier que toutes les commandes de niveau sont bien réglées sur leur position de puissance minimum normale. Dans certains cas, il peut s'avérer utile d'utiliser d'autres réglages pour les besoins suivants : (1). Alignement des niveaux. S'il s'agit d'une chaîne à sonorité enveloppante ou d'un autre type de chaîne à amplificateurs multiples, réduire le niveau de certaines commandes afin d'équilibrer la chaîne en fonction des haut-parleurs de sensibilité différente. (2). Plage ...