NAD 3120 - Manual

3120 Integrated Amplifier
Date of manufacture : Jan 84 - Jan 87
Please note that this document contains the text from the original product brochure, and some technical statements may now be out of date
The NAD 3020 is the most highly praised low-power amplifier in high-fidelity history. Critics around the
world have praised its accuracy, musicality, and seemingly effortless power. The 3020B the latest version
of this classic, contains several improvements but no fundamental change in design.
The 3120 is identical to the 3020B in circuitry and performance, except that it has been simplified by
deleting tone controls and LED power display.
The moderately priced 3020B and 3120 stereo amplifiers provide state-of-the-art performance at
effective output power levels substantially greater than would be expected from their conservative rating
of 25 watts per channel. This remarkable characteristic is made possible by a high-voltage, high-current
output circuit that can deliver short-term bursts of double or triple the rated continuous power output
into the typical impedances of real loudspeakers. NAD’s exclusive Soft Clipping” circuit permits listening
levels even beyond these limits, by reducing harshness at high volume settings. With respect to freedom
from noise at low levels and freedom from distortion at high levels, the 3020B and 3120 are the most
truly “digital ready” amplifiers in their price and power class.
Designed For Real-World Performance
Specification tables and magazine test reports confirm that virtually all modern amplifiers measure well
in the laboratory, with impressive figures for parameters such as the power out-put at 8 ohms and the
signal-to-noise ratio with a short-circuited phono input. But outside of the laboratory, amplifiers are not
all equal.
At home you don’t listen to signal generators, short-circuits, or 8-ohm test resistors; you listen to
complex and dynamic musical waveforms, generated by phono cartridges and reproduced through
loudspeakers whose true impedance is rarely 8 ohms. So, rather than incorporating costly refinements
that yield little or no audible benefit, NAD’s “real world” approach to product design is focused on
obtaining optimum performance under the conditions of everyday use.
Wide Range Phono Preamplifier. The 3020B/3120 is fully ready to accommodate the demands of the
digital Compact Disc via its high-level AUX input, but as long as LP discs remain a primary music source
for most listeners, the quality of the phono preamp circuit must not be compromised.
Instead of the usual low-cost IC, the phono preamplifier section of the 3020B/3120 is a newly designed
discrete transistor circuit whose performance matches that of far more expensive preamp systems. It
interfaces correctly with the high impedance of many magnetic pickup cartridges: its RIAA equalisation is
precise: and it is virtually distortionless - not only with simple sine-wave test tones but also with dynamic
musical waveforms 30 dB above average level. Its signal/noise ratio is close to the theoretical limit, not
only with the short-circuit input that is often used for specifications, but also when a cartridge is
plugged in. Its total dynamic range is approximately 106 dB.
Moving Coil Input
A rear-panel switch provides the increased gain required for low-output moving-coil cartridges, with
extremely low noise, and without the cost and complications of external MC pre-preamps or step-up
transformers.