NAD C740 brochure Features, Impedance Sensing Circuit ISC, Design

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

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”.

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.

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.

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

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!

Design

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.