Nad 7140 User Manual download pdf

7140

S t e reo Receiver

Date of manufacture : Jan 87 - Nov 89

Please note that this document contains the text from the original product brochure, and some technical statements may now be out of date

NAD is internationally recognised as the value leader in Hi-Fi, and the new 7140 stereo receiver provides

an exceptional ratio of performance to price (even by NAD standards).

The tuner section of the 7140 combines the convenience and accuracy of digital frequency-synthesis

tuning with superior stereo sensitivity and quieting.

The phono preamplifier, too, is audibly (and in some cases dramatically) quieter than many other preamp

circuits, not only with moving-magnet pickups but also with low-output moving coil cartridges. The

entire amplifier circuit has ample dynamic range for every program source, including the widest-range

digital Compact Discs.

The powerful high-current output stage of the 7140 drives loudspeakers to surprisingly high volume

levels with clean, solid, full-bodied musical sound and a refreshing freedom from distortion, even in

transient peaks. The exclusive NAD impedance selector allows you to make maximum use of the

amplifier’s power regardless of the true impedance of your speakers.

The 7140 is conservatively rated at 40 watts/channel in the normal stereo mode, not only with test

resistors but with loudspeakers of any impedance. Its 3 dB of IHF Dynamic Headroom means that it will

deliver fully double its rated power (over 80 watts per channel) in brief bursts, important for undistorted

reproduction of the uncompressed transients in Compact Discs and DBX-encoded recordings.

Digital-ready design

The receiver’s line-level inputs will not be overloaded by high-level signal peaks from a Compact Disc

player or digital tape recorder. The 102 dB signal-to-noise ratio of the 7140 exceeds that of any

analogue or digital program source. The low-impedance, low-noise design of the volume and tone

control circuits guarantees that the transparent clarity of the finest analogue and digital recordings will

be preserved.

Low-noise MM/MC phono preamplifier

The phono preamplifier in the 7140 is a discrete (non-IC) design featuring a matched pair of extremely

low-noise transistors in a differential input circuit. It interfaces correctly with the impedance of magnetic

cartridges, and a rear-panel MM/MC selector increases the circuit gain by 20 dB for low-output moving-

coil pickups. The preamp has a push-pull output circuit, like a miniature power amplifier, that provides

ample current to drive the precision RIAA equalisation network without slewing distortion, and its large

dynamic range (107 dB) comfortably accommodates all digitally-mastered LP recordings with room to

spare.

As long as LPs remain a principal music source for many listeners, there must be no compromise in the

quality of the phono preamp circuit.

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Summary of Contents

Page 1

7140 S t e reo ReceiverDate of manufacture : Jan 87 - Nov 89Please note that this document contains the text from the original product brochure, and s

Page 2

High-current output stageElectrical power is the product of voltage and current, but current flowing through the voice coil is whatmakes a loudspeaker

Page 3 - (20Hz - 20kHz) ±0.5dB

PRE-AMP SECTIONPhono inputInput impedance (R and C) 47kΩ / 100pFInput sensitivity, (1kHz, ref. rated power) 3.2mV Signal/Noise ratio (A-weighted with

Page 4 - (120 ~ 240V, 50/60Hz) 240VA

FM TUNER SECTIONInput sensitivity Mono -30dB THD+N 10.3dBf (1.8µV/300Ω)Mono 30dB S/N 14.2dBf (2.8µV/300Ω)Stereo 50dB S/N 36dBf (34µV/300Ω) FM NR off29