GOODSOUND!GoodSound! "Equipment" Archives

Published September 15, 2007


NAD C425 AM/FM Tuner

I make the case in "Whither the Tuner?" this month that a tuner can be essential for an audio system. Though some might find a tuner not part of their budget, the NAD C425, at a very reasonable $299 USD, might change their minds.

Like the other NAD components I’ve reviewed, the C425 has the trademark NAD look. It’s very Bauhaus -- its form follows its function -- but quite attractive. There’s lots of dark gray: the case and front, plus light-gray legends for the various buttons. On the far left, in harmony with the C325BEE integrated amplifier and C525BEE CD player, is the tuner’s power switch. That’s followed, in rightward march, by six soft-touch pushbuttons that control, in order: FM stereo Blend, Memory (for setting presets), FM Mute/Mode (Stereo+Mute or Mono+Unmuted), AM or FM, Display choices, and a button that selects Presets or Tune for the large tuning knob at the panel’s far right.

Between those six buttons and the tuning knob is the display, which provides a lot of info: band and frequency of the selected station, or, if the station’s signal includes Radio Data System (RDS) data, the station name and any RDS text (often the title and artist of the tune playing, or a promotional slogan for the station); indication of a Stereo broadcast; the number of the Preset (if you’ve used one); notification of Blend or FM Mute/Mono being engaged; and the signal’s strength (bars just below "Antenna").

One feature of the C425 that NAD has offered in several of its past tuners is the ability to program in alphanumeric characters to replace any non-RDS station’s basic display of frequency plus band. For instance, instead of "88.7 FM," I could program the C425 to display "WOBO FM," the call letters of that frequency’s local resident (up to eight characters can be displayed). The process is time-consuming and, with the increased use in the US of RDS, often unnecessary, but it’s a nice option.

The C425’s remote control offers all of the front-panel controls as well as a Sleep timer (90 minutes max) and a display Dimmer. Unlike NAD’s C525BEE CD player, the C425 doesn’t respond to power-on/off commands from the C325BEE integrated amp’s remote. According to NAD, this is in response to the requests of custom installers. However, if you wish, you can connect a patch cord between the C425’s 12V trigger input and the C325BEE’s trigger output.

The C425’s rear panel is nearly as simple as that of the C525BEE CD player. There are an F-style FM antenna connection, two connectors for the supplied AM loop antenna, stereo audio outputs, and inputs for both infrared control and the 12V trigger; the tuner’s nine-pin RS-232 port can connect it to a home-automation system or PC.

Opening the lid of the unit revealed a circuit board that takes up less than half of the interior. As is usual for NAD gear, the component layout is clean and neat.


I used the NAD C425 with two systems: NAD’s own C325BEE integrated amp feeding (via 14-gauge cable) a pair of PSB Alpha A/V speakers and 5i powered subwoofer, and a McIntosh C27 preamp and Carver TFM-15cb power amp driving Celestion 3 speakers and an Advent 12" powered sub; speaker cables in both systems were from AR. The latter system is in my home office and consists largely of gear that once graced my reference system but that I can’t bear to part with. The C425’s counterpart in this system was a bit of a mismatch: a Magnum Dynalab Etude tuner that, in its day, sold for more than four times the C425’s price. Interconnects in both systems are nothing fancy, but are more substantial than those supplied with the C425.


Weather can have some interesting effects on FM reception. Because FM signals carry farther and stronger when it’s very warm outside, my first tests of the C425 may have been a mite unusual: it was 91F. I’d connected the tuner to a BIC FM-10 Beam Box antenna -- a relic of the 1980s that, through all the years since, has remained my favorite indoor FM antenna (and is all my highly sensitive and selective Magnum Dynalab Etude has ever needed). In these hot conditions the C425 received 37 FM stations whose signals were listenable (a subjective determination of how much hiss I heard); another two were audible but unlistenable. Had I been obsessive-compulsive about trying to receive any and all signals, it could have been done, though with difficulty: because the C425’s tuning knob is stepped, turning the knob too quickly automatically puts the tuner in Seek mode, which has a fairly high threshold. Seek mode detected only 34 signals, missing a few outlying or low-powered noncommercial stations. Under similar conditions and using the same antenna, the Magnum Dynalab Etude received 43 stations in full and listenable stereo, and another four that were OK in mono but noisy in stereo.

The RDS feature was an unexpected boon. It was nice to be listening to a song in FM and see the artist’s name and song title scrolling across the display. Very handy!

The C425’s AM reception was typical for a 21st-century tuner, combining limited bandwidth (it topped out at probably 2.5-3kHz) with limited sensitivity. Then again, most AM stations broadcast talk, sports, or some other spoken-word programming, so the lack of bandwidth isn’t crucial. However, even when trying to tune in the local 50,000W (as big as they get) behemoth that’s 12 miles from my home, I had to manipulate the AM loop antenna for clear reception.


I’ve just described the C425’s AM sound. Its FM performance merits more description, but in a phrase, it was quite good. The only qualm I had was that the C425 was particular about how much signal input it was fed. It wanted a fairly strong signal to reach effective quieting, but, in its defense, once it reached that point, the signal/noise ratio improved quickly. And once it had taken care of the hiss, the C425 put on a great audio show.

One aspect of the C425’s performance that I found exceptional was its ability to reveal the quality of sound a station was broadcasting. Most commercial and some noncom FM stations use heavy signal processing: compression to make soft sounds louder, limiting to keep loud sounds under control, and heavy doses of equalization to make the music sound "fat" on cheap radios. The C425 let me know right away which stations were processing their signals to death and which weren’t. For instance, one local rock station noted for its chainsaw audio sounded sibilant, while the local classical outlet sounded very good. That’s been my experience with tuners designed in Canada (as were both the NAD and my Magnum Dynalab) -- most Canadian stations don’t subject their signals to as much processing as do US stations, and therefore sound more natural.


The NAD C425 is a fine tuner within its limitations -- which aren’t that great, given its price. It needs a fairly strong FM signal to limit the hiss -- but not too strong, or the front end will often distort. The C425 is ideal for most suburban locations, but I don’t recommend it for areas in which there’s a station nearly every 200kHz (as in, say, New Jersey between New York City and Philadelphia). Its useful features include 30 presets (any combination of AM or FM), RDS display when available, easy insertion into multiroom systems via its RS-232 port, and, above all, excellent FM sound. While it’s not my favorite model of the NAD trio completed by the C525BEE CD player and C325BEE integrated amplifier, it should satisfy most users, even those few who still listen critically to FM, and will do so at a bargain price. NAD has produced another fine model.

...Thom Moon

Price of equipment reviewed

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