User manual NAD C270

[. . . ] 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. [. . . ] Adjust the Level Control so that the speakers driven by the C270 have the correct volume level compared to the other speakers, judging from your listening position. Extended volume control range Many systems have so much voltage gain that the speakers (or your ears) are overdriven 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 the input level is reduced, you can turn up your processor's or preamplifier's volume control, making more effective use 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. Any residual hum or hiss that does not go away when the Volume is turned down). This facility allows to "Bi-Amp" such speakers, where a separate power amplifier is used for the LF and HF section, which may improve overall sound quality. When Bi-Amping with different models of power amplifiers, it is likely to occur that one power amplifier has more "gain" than the other, resulting in a mis-match in level for the woofer and tweeter of the speaker. Adjust the level control so that woofer and tweeter are in perfect balance with each other (identical gain of power amplifiers). Connect the output from a pre-amplifier or processor, such as a surround-sound decoder, to this set of inputs. Use a twin RCA-toRCA lead to connect to the left and right `Audio Output' of the preamp or processor to the Fixed-In sockets. NOTES: Always turn the C270 and other components in the system off before connecting or disconnecting anything to the "Fixed In" or Variable In" sockets. When using the "Variable In" sockets, make sure the "input Select" switch (No. INPUT LEVEL CONTROL The Input Level control works in combination with "Variable In" (No. With the control the volume to the power amplifier can be adjusted from zero (counter clock-wise) to maximum (turned up all the way clock-wise). Refer also to section "Variable In" in this chapter for more information. NOTE: Always turn the C270 and other components in the system off before connecting or disconnecting anything to the "Fixed In" or Variable In" sockets. FIXED IN The Fixed Inputs take the input signal straight to the power amplifier's circuitry. This set of inputs is normally used in a system with only one power amplifier or multiple but identical power amplifiers. Refer also to section "Variable In" in this chapter for more information. Connect the output from a pre-amplifier or processor, such as a surround-sound decoder, to this set of inputs. [. . . ] SOFT CLIPPINGTM When an amplifier is driven beyond its specified power output, a hard, distorted sound can be heard on very loud sounds. This is caused by the amplifier cutting off or `hard clipping' the peaks of sound that it was not designed to reproduce. the NAD Soft ClippingTM circuit gently limits the output of the system to minimise audible distortion if the amplifier is overdriven. If your listening involves moderate power levels you may leave the Soft ClippingTM switch to Off. [. . . ]