C740 Stereo Receiver
• 2 x 35 Watts continuous • 50 Watts Dynamic Power into 8 ohms
• 140 Watts Dynamic Power into 2 ohms • Impedance Sensing Circuit (ISC) topology
• Full System Remote control • All sockets Gold plated • Tone defeat
• Pre-out / Main-in • Soft Clipping • 30 Station random presets (AM or FM) in 3 banks
• 25 kHz tuning steps • MOS-FET RF section and Front-End
• NAD-Link for remote control capability
Impedance Sensing Circuit (ISC)
The NAD C740 is one of the first products to benefit from one of Bjørn
Erik Edvardsen's latest developments: ISC topology
NAD receivers have always stood out from the rest, as the engineers never
compromised the quality of a receiver compared to that of separate
components. The C740 is an excellent illustration of this philosophy as it is
the combination of the C440 tuner and C340 amplifier combined in one
chassis. The only difference is the slightly lower output power of the C740
compared to the C340, but otherwise the C740 is literally the sum of the
separate components. NAD refers to this concept as “Building Block”.
The ISC topology allows the C740 to deliver maximum performance under
virtually any circumstance, independent of the loudspeakers it is driving.
The circuitry automatically recognizes the impedance characteristics of the
loudspeaker and will then adjust its power supply settings to best cope
with that specific load. This also gives it an unusual characteristic
compared to traditional amplifiers when measuring its continuous output
power; the RMS output power remains the same at 35 Watts with either an
eight or a four ohms load. This is not unusual for NAD however.
NAD takes a stance to the mindless “brochure power” approach which
doesn't give a realistic indication of an amplifier's true capabilities.
Instead, the ISC topology is a practical approach to enable an amplifier to
easily deal with dynamics and difficult loads. More meaningful are the
C740's dynamic capabilities; up to 140 Watts into 2 ohms and up to 30
amps current capability!
Features
The C740 is fully remote controlled and comes supplied with the NAD C
Series system remote control. As the C740 also has NAD Link the remote
control will operate many other NAD products such as CD players, tuners etc.
Flexibility is another NAD strong point. The C740 has 6 line inputs
(including 2 tape in/outputs with dubbing facility) and the pre-amplifier
section can be separated from the power amplifier for easy upgrades (bi-
amping, for instance) or adding ancillary equipment without making the
C740 redundant. The headphone socket will drive virtually any non-
electrostatic headphone.
Design
With 30 presets available you can store all your favorite radio stations.
These presets can be any combination of AM and FM stations: 25 presets
for FM and 5 for AM, or 17 for FM and 13 for AM, for instance. You can
store the presets in any of the three different banks, labeled A, B or C.
This way you can organize the presets to suit personal preferences. When
attempting to listen to weak stations, the BLEND function reduces the
background noise while still retaining adequate stereo separation.
The C740 will allow you to individually name each preset with up to
8 characters. Once you have named your presets you don't need to
remember which frequency goes with what radio station, the name is
indicated in the display every time the preset is recalled. Auto Search
automatically stops at the next strong radio signal it comes across
and optimizes tuning. Weaker radio stations can be tuned into manually.
The MOS-FET RF section and Front-End design together with high quality
components and careful PCB layout guarantees excellent sensitivity with
low intermodulation distortion to provide noise-free reception. Although
AM can never reach the quality of any FM transmission, the Model C740's
AM section retains excellent clarity together with low background noise.
The traditional but still very valid and useful NAD features such as Soft
Clipping and Pre-out/Main-ins remain, and all the in- and output sockets
are gold plated for long-term contact reliability.
Other design features include the generous power supply with over-rated
output devices further lead to low noise and low distortion for the entire
amplifier. Although the protection circuitry will protect the amplifier
against blatant cases of abuse, such as short circuiting the speakers, it
doesn't intrude on or impair the integrity of the signal even under the most
demanding conditions. Its superb build quality, using selected, close-
tolerance components and excellent finish with aluminum front panel
ensure that the C740 is a receiver that will provide many years of excellent
and trouble-free performance.
PRELIMINARY SPECIFICATIONS - NAD C 740
Continuous average power output into 8Ω
35W (15.4dBW)
(Min power per channel, 20Hz - 20kHz both channels driven with no more than rated distortion)
Rated distortion
Clipping power
(THD 20Hz - 20kHz)
0.03%
40W
(max continuous power per channel)
IHF dynamic headroom at 8Ω
1.5dB
IHF dynamic power
(max short term power per channel)
8Ω 50W (17dBW)
4Ω 90W (19.5dBW)
2Ω 140W (21.5dBW)
<0.03%
THD
(20Hz - 20kHz, from 250mW to rated power)
Signal to noise ratio
A weighted; ref. 1W 90dB
A weighted; ref. rated power 104dB
Headphones output impedance
Treble control
Bass control
220Ω
±5dB at 10kHz
±7dB at 100Hz
FM Tuner Section
Usable input sensitivity
FM Mono 11.2 dBf, 1.0 µV, IHF, 0.9 µV, DIN
FM Stereo 17.2 dBf, 2.0 µV, IHF, 20 µV, DIN
FM Mono 16.1 dBf, 1.7 µV
FM Stereo 36.1 dBf, 20 µV
2.5 dB
50 dB Quieting sensitivity
Capture Ratio (FM)
Harmonic Distortion
FM Mono 0.1%
FM Stereo 0.15%
@1kHz >45dB
± 1.5 dB 30Hz - 15 kHz
Channel separation
Frequency Response
AM Tuner Section
Usable Sensitivity
Selectivity
IF Rejection
Signal / Noise Ratio
Harmonic Distortion
10 mV
30 dB
40 dB
40 dB
0.7%
Physical Specifications
Dimensions (W x H x D)
17.125" x 3.375" x 11.5"
(435 x 110 x 290mm)
17.8lbs (8.1kg)
Net weight
Shipping weight
20lbs (9.1kg)
Appearance and features are tentative.
NAD reserves the right to change specifications or design at any time without notice. All specifications are those in effect at time of printing.
Printed in Canada.
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