NAD S400 Silver Line RDS FM tuner


NAD S400 Silver Line FM RDS Tuner


The Silver Line from NAD is mainly known for its exceptional integrated amplifier S300, but luckily for all those who were looking for a matching tuner, NAD designed a top-notch machine called S400. Manufactured in Denmark and introduced for the first time around the year 1998 with the retail price of 1000USD. Not cheap, but for that money you got an excellent piece of source for your HiFi.

Typical Silver Line design and quality of assembly. Every single side of the enclosure is made of out thick, brushed aluminium plates. The sides have a heat-sink shape, the face plate is flat and holds a few ergonomic and precise buttons and a dimmable blue-coloured display. Individual elements perfectly fit each other, giving a felling of a very solid and robust construction. The well known Silver Line’s issue with the front plate getting yellowish after a few years doesn’t necessarily concern the S400. At least I couldn’t notice it on this particular unit. The only thing, that I was disappointed with it the… miserable stock remote control. Typical NAD controller, briefly speaking plastic is fantastic, but… it was possible to buy an optional, full aluminium Silver Line system RC with a display called S70. The only problem was the extra price of around 250 euro!

NAD S400 guts inside view

The design of the guts is clean, modular and very eyes-friendly. The heart of the machine is a fair-sized toroidal power transformer brought by Toroid and there are in total three separate PCBs. One holds the tuner section, one secures the power supply and the last one sits behind the face plate operating the buttons, display, RC sensor etc. Thick aluminium partition serves as a shield against interferences between the display / buttons circuit board and the rest of the electronics.


NAD S400 power transformer


The tuner module is a Danish-made Larsholt with two 75Ω antenna inputs, accompanied by Philips power capacitors 3 x 2200μF and a few Philips processors. Japanese Takamisawa serves as output relay.





Manufacturer's description

It is ever more difficult to find a sonically satisfying FM tuner. And the few designs that do qualify are increasingly burdened by buttons, features, and functions – too many of them of dubious utility. NAD recognises that FM radio remains a valuable source of music and other programming, so the Silver Series S 400 FM Tuner was carefully designed to fly in the face of these trends.


The S 400 supports an innovative, genuinely high performance FM section with a deliberately simplified interface. The S 400’s technical design is highlighted by dual antenna inputs, each equipped with a fully independent, low-noise, dual-gate MOSFET RF amplifier. This very atypical arrangement avoids any possibility of interference between inputs, while providing an invaluable convenience to those using two antennas or an antenna plus a cable system to maximise listening options.
Triple-stage IF filtering incorporates user-selectable (Wide/Narrow) bandwidth, a traditional feature that enables the S 400 to offer the best-of-both-worlds performance: maximum quieting from weak signals, and fully maximised audio quality from strong, closely spaced ones. (Virtually all competitive tuners and receivers compromise performance in these areas.)


Additional advanced elements include physically separate and independently regulated power supplies for analogue-audio, RF, and digital-logic circuits, and a sophisticated, highly effective implementation of the critical 19 kHz pilot-tone filter. There is also no use of the inductors normally found in tuners, and this guarantees minimum phase shifting. The S 400’s user-selectable blend mode permits highly effective quieting of very weak or noisy signals while still preserving substantial stereo image.


As is quite common among digital tuners today the S 400 provides 30 preset memory locations the user may program to instantly recall favourite stations. Entirely uncommon is the fact that each of the tuner’s 30 presets store not just a station by name, utilising the programmable 8 character display input, but also the selected antenna input, wide/narrow IF mode setting, and mono or stereo decoding status. The S 400 also provides a remote control, and NAD-Link includes the necessary interface for fully integrated system operation.

Technical specification

Usable input sensitivity (60dB S/N) FM Mono 1.0μV
  FM Stereo -25μV
50dB Quieting sensitivity FM Mono 1.6μV
  FM Stereo 19μV
Capture Ratio (FM)   2 dB
Image Rejection   100 dB
Harmonic Distortion FM Mono 0,15%
  FM Stereo 0,20%
Signal/noise ratio Mono 80dB
  Stereo 78dB
Channel separation 1kHz 45dB min.
Frequency Response ±0.5 dB 20Hz – 15 kHz
Tuning accuracy   ±0.002%
Remote control   Yes
Physical specifications    
Dimensions (W x H x D)   450 x 67 x 285mm
Net weight   4.56kg
Shipping weight   5.67kg


I compare it with Sansui TU-717 while they connected to same antenna. FM reception is almost same. NAD S400 a little bit better. But sound quality is much higher then the TU-717 and also Onkyo T-9990. Bass, mid and high frequency is very well balanced. Noting disturbs you.

,, 9th May 2007

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