User manual NAD T975

[. . . ] 1 Read instructions - All the safety and operating instructions should be read before the product is operated. 2 Retain instructions - The safety and operating instructions should be retained for future reference. 3 Heed Warnings - All warnings on the product and in the operating instructions should be adhered to. 4 Follow Instructions - All operating and use instructions should be followed. [. . . ] Any amplifier can be overdriven if it is played too loud, exceeding the maximum output power. Under such circumstances, amplifiers produce extreme high levels of distortion which, besides sounding very unpleasant, can damage your loudspeakers. the Soft Clipping circuit suppresses such distortion and minimizes the risk of damage to speakers. This is particularly important with movie soundtracks which often contain very dynamic outbursts in which, unlike music, it is difficult to hear this potentially damaging distortion. The Soft Clipping LED on the front panel illuminates when the Soft Clipping circuit is engaged. The 12V trigger connection on the back panel allows the amplifier to be switched from On to Stand-by and vice-versa remotely. This way, the T975 can be part of a system which can be turned on and off with a single command, easing operation. The 12V trigger also allows the amplifier to be installed in places not in easy reach. THE DESIGN The NAD T975 houses seven individual amplifiers, each on separate circuit board. Each amplifier channel acts as a "mono block" within the chassis. each input connector , and set of loudspeaker output terminals , is directly connected to that channel's circuit board. furthermore , this modular design increases reliability and thermal efficiency. The input circuit uses a totally new dual differential input topology that operates in true Class-A mode. The special HolmgrenTM toroidal transformer has less hum and magnetic leakage than conventional toroidal transformers, but retains the usual benefits of high efficiency and high power-to-weight ratio. This provides highly effective protection that does not effect audio performance. Each channel is protected against excess temperature, DC fault and loudspeaker short-circuit. The T975's inherently conservative, high-voltage/high-current output stage has been designed for years of trouble-free service. POWERDRIVE To meet the diverse requirements of high current drive and high dynamic power, our patented PowerDrive amplifier circuit will build further on our reputation for amazingly effective power. By adding a second high-voltage rail to our well regulated high-current power supply, we get an "overdrive" that can nearly double the continuous power on a short term dynamic power basis. This is a further development and refinement of our renowned Power Envelope circuit, utilized by NAD in the 80's and 90's. PowerDrive differs from Power Envelope in that it offers greater amplifier stability and low impedance drive capability, resulting in less distortion when driving real speakers with real program material INSTALLATION PRECAUTIONS WARNING - To reduce the risk of fire or electrical shock, do not expose the amplifier to rain or moisture. CAUTION - For units factory-set at 115 volts AC match the wide blade of the power plug to the wide slot of the power outlet, to prevent electrical shock. [. . . ] NOTE: Speakers must operate in phase with each other in order to produce a proper 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 terminal marked red (positive) on the amplifier. When an amplifier is driven beyond its specified power output it normally produces "hard clipping" or distortion of the signal. We recommend that the Soft Clipping switch on the back panel of the T975 be left in the ON position when system is being operated at levels that might exceed the amplifier's power capacity. [. . . ]