NAD T975 User manual

NAD has a well-deserved reputation for producing amplifiers with extraordinary performance and always
at an affordable price. The T975 keeps this tradition alive and well by applying over 30 years of experience
to the challenge of producing a very high power, high performance, seven channel power amplifier able to
provide the musical muscle required for even the most sophisticated Home Theaters.
Consumers are often confused about power ratings, with many ‘mass market’ brands claiming power
output levels that seem too good to be true. These inflated claims quickly fall short at the first listen. NAD’s
Full Disclosure Power ratings are the most conservative in the industry, and allow the T975 to handle any
speaker load and any program material. The benefit of NAD’s Full Disclosure Power is the total elimination of
audible distortion at any listening level. This provides pinpoint imaging and spine tingling realism with music
and movies alike.
The 7-Channel NAD T975 is a perfect accompaniment to the T175 A/V Tuner Preamplifier.
Design
As might be expected in an amplifier capable of one kilowatt (1,000 watts) of continuous power output, the
power supply needs to be very carefully designed. As usual, NAD favors the toroidal transformer type for its
superior regulation and low stray magnetic field. Our exclusive “Holmgren” transformer uses a special core
design and materials to enhance efficiency and make the transformer less sensitive to DC offsets on the
AC mains voltage. Over 80,000 uF of storage capacitance ensure an ample reserve of power for even the
most demanding music and film soundtracks.
The T975 employs mono-block construction for each of its seven channels. Every element of each channel’s
circuitry, save the power supply, is fully independent thus eliminating inter-channel influences as a concern.
The T975 employs active ground isolation to further eliminate any possibility of inter-channel interference
even when more than one preamplifier is driving the power amp (as might be the case in a custom installation).
Each section features an FET Class A input and driver stage circuits, and a high-current output-stage design,
employing high speed, discrete output devices to promulgate superb dynamic quality. The result is musical
detail, impact, and soundstage stability and depth unmatched by multi-channel amps of even two and three
times the T975’s price. NAD’s proprietary Soft Clipping™ (defeatable) maintains sonic quality and offers
speaker protection even under severe overdrive conditions.
Individual gain adjustment for each channel promotes easy, accurate system configuration, as does the
T 975 Seven Channel Power Amplifier
• 7 x 140W Simultaneous Full Disclosure Power
• 7 x 250W Minimum Continuous Power (FTC)
• Dynamic Power - 230W 8 Ohms, 390W 4 Ohms, 450W 2 Ohms
• PowerDrive™ amplifier technology
• Mono-block, Modular construction
• Balanced Differential, Class A input circuit topology
• Low loss, massive Holmgren toroidal mains transformer
• Input gain control for each individual channel
• Thermostatically controlled fan with signal tracking circuit
• Custom 5-Way Binding Posts
• 12V Trigger for advanced control options
• NAD Soft Clipping™
• Detachable AC cord
Features
Details

T975’s integral 12V trigger turn-on response. This multi-channel
amplifier delivers its output via heavy-duty “five-way” connectors.
Ruggedness and in-system reliability are critical to successful
home theatre systems. The T975 uses a unique variable speed
fan cooling system first introduced on the M25 Masters Series
amplifier, allowing the T975 to deliver massive amounts of power
for hours on end. Many lesser amps thermally protect and cycle
on and off when asked to perform at their maximum causing an
unpleasant disruption of the movie. While a well designed forced
air system can eliminate thermal cycling, it is crucial to keep the
noise of the cooling fan from intruding - especially during quiet
passages of the movie or music. To this end, we have developed a
unique circuit that measures not only the operating temperature
but also the level of the input signal, automatically silencing the
fans during quiet passages.
This amplifier utilizes a combination of fuse and electronic non-
intrusive protection: dependable, fail-safe, and sonically benign.
Each channel is fully protected against excess temperature, DC
fault, and loudspeaker short-circuit.
PowerDrive™
The T975 also benefits from NAD’s proprietary PowerDrive™
circuit topology, now well established and used throughout
the NAD product range. The PowerDrive topology allows the
T975 to deliver maximum performance under virtually any
circumstance, independent of the loudspeakers it is driving. The
circuitry automatically senses the impedance characteristics of
the loudspeaker and will then adjust its power supply settings
to best cope with that specific load. PowerDrive topology is a
practical approach to enable an amplifier to easily deal with
musical dynamics and difficult speaker loads. Thus we have the
highly desirable characteristics of high dynamic power and low
impedance drive capability in one affordable package.
NAD also takes a stand against the meaningless “brochure power”
touted by many of our competitors by offering Full Disclosure
Power specs. We specify minimum continuous power, across the
entire audible range of frequencies, at rated distortion, for both
8 and 4 Ohms with all channels driven simultaneously. Perhaps
even more importantly, we also specify Dynamic Power at 8, 4,
and even 2 Ohms, which better describes the way the amplifier
will perform in the real world, with musical signals and reactive
loudspeaker loads.
But even the most carefully reported specs cannot fully describe
the sonic performance of an amplifier. Only your own ears can
finally judge our achievement. We urge you to listen and compare
NAD to other products in its price range, and even higher. We
don’t think you’ll find anything that comes close to offering the
T975’s overall musical satisfaction, well-rounded performance,
and stellar value for money.
SPECIFICATIONS
Simultaneous Full Disclosure Power
(4/8 Ohms, 20Hz - 20kHz, at rated distortion)
Minimum Continuous Power (FTC)
Rated Distortion (THD 20Hz-20kHz)
Clipping Power (0.1% THD)
IHF dynamic power at 8 Ohms
IHF dynamic power at 4 Ohms
IHF dynamic power at 2 Ohms
Damping Factor
Input Impedance
Input Sensitivity
7 x 140W (21.5dBW)
7 x 250W (24dBW)
0.03%
170W (22.1dBW)
230W (24dBW)
390W (26dBW)
450W (26.5dBW)
ref. 8 Ohms, 50Hz >300
50K
1.1V
Voltage Gain
Frequency Response
Signal/Noise Ratio ref. 1W
ref. rated power
Net Dimensions (W x H x D)
Gross Dimensions (W x H x D)*
Net Weight
Shipping Weight
29.0dB
20Hz - 20kHz +0, -0.2dB
2Hz - 100kHz -3dB
95 dB
125dB
17 1/8 x 7 1/8 x 17 3/4”
(435 x 181 x 451mm)
17 1/8 x 7 5/8 x 18 3/4”
(435 x 194 x 476mm)
68 lbs (31kg)
72 lbs (33kg)
* Gross dimensions include volume knob / speaker terminals / connectors / feet.
Note: Installers should allow a minimum clearance of 2 - 4 inches for
wire management.
NAD Electronics International reserves the right to change specications or features without notice. NAD is a registered trademark of NAD Electronics
International. All rights reserved. No part of this publication may be reproduced, stored, or transmitted in any form whatsoever without the written
permission of NAD Electronics International. © 08/07 NAD Electronics International.
www.NADelectronics.com