This week we’re testing the NAD C338, a connected, hi-fi stereo amplifier which, in addition to being equipped with Hypex UCD amplifier modules, integrates an assortment of analog and digital inputs as well as Bluetooth and Wifi wireless streaming modules. An amplifier compatible with HD audio, Deezer, Spotify, Qobuz, Tidal, Plex, Tune In, and YouTube… a bargain?
NAD C338: Class D Hypex UCD amplification
The NAD C338 amplifier is a purely analog amplifier, unlike models such as the NAD D3020 or NAD D7050, for example, which are more compact and less powerful. NAD has chosen to equip the NAD C338 with Hypex UCD modules, just as it did for the NAD C368 and NAD C388. These amplifier modules make these three amplifiers only slightly sensitive to speaker impedance (identical power delivered into 4 and 8 Ohms) while ensuring a generous power supply. Such particularities aim to ensure that the NAD C338 won’t color the sound when paired with different speakers.
NAD C338: connectors and DAC compatibility
The NAD C338 amplifier features a selection of analog and digital inputs. Up to three analog stereo sources may be connected simultaneously, including a turntable with a moving magnet cartridge. Four S/PDIF digital inputs are present (2 RCA, 2 Toslink), and each is compatible with PCM stream up to 24-bit/192kHz. Lastly, a subwoofer pre-out (RCA mono) is available, in addition to a headphone output (6,35 mm mini-jack) on the amplifier’s front panel. Three antennas are provided with the NAD C338: two for the WiFi router and one for the Bluetooth transmitter.
NAD C338: Chromecast built-in technology
Over the course of the past few years, streaming audio files shared on a local network or stored on a smartphone has become a highly sought-after function. The dematerialization of the CD-Audio in favor of the lossless FLAC format, along with the increasing availability of studio-quality files (Qobuz, HDTracks), have brought high-fidelity restitution to a wider public. Just as sought after (if not more): the ability to stream music from services such as Deezer, Spotify, Qobuz and Tidal directly to a hi-fi amplifier. Nevertheless, the considerable diversity of services, file formats and operating systems adopted by smartphones and computers means that coming to terms on a universal solution is challenging. Faced with this challenge, a lot of listeners turn to Bluetooth transmission, a universal transmission protocol involving a damaging compression process.
For its part, Sonos has taken the bull by the horns by promptly allowing users to stream audio files and music streaming services… but only with its own speakers and amplifiers. While these aren’t bad, they can’t compare with hi-fi amplifiers such as those built by NAD or other specialized brands. The problem is that the major players in the hi-fi community have taken their time proposing an alternative to Sonos streaming. At the same time, alternative streaming solutions such as Yamaha MusicCast and Denon Heos, for example, are not totally satisfactory. For one thing, all streaming services are not supported, and for another, the user must rely on the manufacturer’s app… with all the ups and downs that come along with the technological revamps initiated by music streaming services.
NAD has made a different choice and has integrated Google’s universal streaming technology, known as Chromecast built-in, into its NAD C338 amplifier.
The first advantage: Chromecast technology is directly integrated into the official apps of music streaming services and a number of other services (YouTube, Tune In, Plex, etc.). Second, the audio stream doesn’t pass through the smartphone or computer used to send commands to the amplifier (as it does with AirPlay, for example). Rather, it’s the NAD C338 amplifier which connects to Deezer’s server to stream music in lossless format. The smartphone can thus be distanced from the WiFi network without negatively affecting playback quality. Lastly, Chromecast is compatible with Hi-Res Audio.
NAD C338: Using Chromecast to play audio files stored on a smartphone
To stream FLAC files stored on a smartphone, an audio playback app compatible with Chromecast is necessary. This cannot be Google Play Music, which only enables playback for files stored on the user’s cloud (in MP3 format, up to about 20,000). There’s a simple reason for this: the Chromecast technology integrated into the NAD C338 amplifier (just like any other Chromecast technology) needs to connect to a server. It is thus necessary to install a third-party app which integrates a server and is compatible with Chromecast. Another option would be to use the audio player proposed by a smartphone with the DLNA direct playback function enabled. As the NAD C338 is compatible with DLNA DMR, this solution is just as effective. And lossless, once again.
Note that the compatible formats are those handled by the playback app.
NAD C338: Spotify Connect
A notable Spotify feature: the service lets users listen either via its mobile app (iOS, Android) or desktop app (Windows, Mac OS, Linux) and supports both the Chromecast and Spotify Connect protocols. There is no difference between these two methods. Spotify imposes Spotify Connect upon all manufacturers who decide to propose access to its service.
NAD C338: advanced settings
The NAD C338 amplifier can be set to turn on automatically (Auto Sense mode) as soon an incoming signal is detected by its first optical input. A setting to activate (via the remote control or NAD app), and one which is highly practical for users who want their amplifier and television to turn on simultaneously. This is a bit like the HDMI-CEC function on home theater receivers set to turn on automatically. However, the amplifier doesn’t turn off when the television is turned off (because there is no optical signal), but only after 30 minutes of inactivity.
The Bass EQ mode may be activated directly on the amplifier, via its IR remote control, or with the NAD Remote app, and it will boost the lows by a few decibels. No other tone settings are available.
NAD C338: setup
Google can be thanked once again, because the NAD C338 (or any other device featuring Chromecast Built In technology) may be configured by simply installing the Google Home app (Android, iOS). And it’s child’s play.
NAD C338: test conditions
We listened to the NAD C338 with the Jean-Marie Reynaud Lucia and Klipsch Heresy III speakers, connected with Norstone Arran MC cables. Two very different speakers, as the first is a compact two-way model benefiting from audiophile craftsmanship, while the second aims for high sensitivity with a sizeable bass driver and acoustic horns. We mainly listened to FLAC audio files in DLNA mode, in addition to Deezer and Tune In.
NAD C338: listening impressions
Before getting down to the NAD C338 amplifier’s performance, let us say a few words about the user experience, which is very good, as we had expected. The amplifier’s WiFi function was convincing, without any network interruptions when moving from one room to the next, although in our case there were no walls to disrupt the WiFi signal. The minimalist front panel prevents the listener from getting lost in a sea of buttons, and the user experience offered by the Chromecast-compatible mobile apps is impeccable.
The NAD C338’s tonal balance closely resembles that of the NAD C388, which is to say that it has a serene and laid-back sound signature. The C338 proves to be more energetic at low volume and offers slightly more incisive highs, but the listening experience is above all a smooth one.
The sound delivery never shocks the listener, who can thus sit back and become fully immersed in the music.
The layering of the soundstage is clear. The NAD C338’s performance is consistent and its neutrality is easy to appreciate. It refrained from unnecessarily calling upon the compression driver domes of our Klipsch Heresy III speakers, and yet it maintained perfect control of their 12” woofers. This amplifier is also very comfortable with the JMR Lucia, its restraint in the mids reinforced the balance of this speaker further still.
NAD C338: conclusions
What we liked: the neutral sound, the serene sound restitution, the integration of Google Chromecast and its ease of use, the connectivity featuring an optical input and auto-on function, the compact format.
What we would have liked: an Ethernet port for a cabled network connection (but the dual WiFi antenna should be sufficient).
The NAD C338 achieves its goal of offering both first-rate streaming functions and a consistently balanced sound. We recommend it for listeners looking for an amplifier able to rein in speakers which are too turbulent in the mids or lack control in the lows, as well as those wishing to enjoy an authoritative hi-fi and stereo home theater performance with less expressive speakers. The NAD C338 is a consensual yet convincing amplifier. The very definition of a sure thing.
This post is also available in: French