Following on from the surprising M10 and M33, NAD is now offering us a more or less equivalent performance package nestled in a completely different shell. The NAD C658 and the NAD C298 is presented in the same livery as the manufacturer’s classic range, and its performance is quite astonishing for the price on offer.
These NAD components probably foreshadow what our systems will be like in the future. While the power amplification retains a familiar format, it’s the sources that are the real upheaval. Here, there is no longer any device for reading a physical medium. Instead, a network player and a preamp called the NAD C658 replace them, putting the emphasis on dematerialised media. However, to ensure a smooth transition in our listening habits, NAD has taken care to equip it with numerous inputs so that it can also make the most of current and older sources, both digital and analogue. It also acts as a DAC and preamplifier.
Great versatility
A veritable bridge between two eras, or even two worlds, the C658 plays the excellence card. This choice is tangible right from the analogue sections. For example, an unusual feature in equipment that is essentially digital, it has a Phono MM input for a vinyl turntable. Similarly, there are two analogue inputs at line level, so that it can accept the connection of older generation analogue sources.
Of course, the connectivity dedicated to digital streams is also very comprehensive. There are two optical inputs, two coaxial inputs and a USB port. The NAD C658 can therefore handle streams from a CD drive or television, for example, to deliver quality sound. Similarly, it meets the current demand for wireless links. Here again, NAD has opted for high-quality solutions.
It has a latest-generation Bluetooth apt-X HD transmitter. This link enables files stored on a smartphone, for example, to be used directly under optimum conditions, including hi-res audio streams, which is not the case with basic Bluetooth. What’s more, as this link is reversible, it allows wireless headphones to be used from the C658.
BluOS compatible
Finally, the NAD C658 can be connected to the home network to access streaming services on the Net, either via a wired connection using the Ethernet port on the RJ-45 socket on the rear panel, or directly via Wi-Fi. In the latter case, NAD has equipped the C658 with a dual-band wi-fi transmitter to ensure a reliable connection with a constant data rate. What’s more, equipped with BluOS hi-res audio streaming technology, it can access more than fifteen high-quality streaming services, as well as a large number of web radios. This technology is also open to multi-room use. This means that the NAD C658 can be used to broadcast music throughout the house while managing several listening zones individually, provided that there is BluOS-compatible equipment in the home.
An ESS Sabre 32-bit DAC
But while accepting streams is one thing, they still need to be managed correctly. Here again, the brand has opted for quality by equipping the NAD C658 with a 32-bit ESS Sabre DAC. A component renowned for its very low jitter and exceptional dynamic range. It is natively compatible with 32-bit/192 kHz hi-res audio streams, so you can fully exploit their subtleties.
However, what’s the point of processing audio streams to perfection and reproducing them with total respect for timbre, even with quality speakers, if the room in which you’re listening has difficult acoustics. Many reproductions suffer from coloration or tonal anomalies linked to poor room acoustics. NAD has made this observation. To solve this problem and restore perfect tonal balance, the brand has equipped the NAD C658 with DIRAC Live Room Correction acoustic correction technology. A device for compensating for the acoustic anomalies of a room that is a benchmark on the market. In addition to rebalancing the system’s overall frequency response, DIRAC detects and corrects undesirable resonance phenomena. The impulse response of the loudspeakers is also quantified and the system’s response is adapted accordingly to optimise it. In short, the aim of these multiple adjustments is to ensure that the listening experience fully respects the recording conditions.
An amplifier with generous power
To fully exploit the capabilities of its network player, NAD wanted to combine it with a power amplifier that also uses the latest generation technologies: the NAD C298. Based on Class D digital output stages, it is capable of delivering power of up to 2 x 185 W.
Digital amplifiers sometimes have a bad reputation in the audiophile world. They are sometimes accused of a certain aggressiveness, or even excessive brightness. Aware of these remarks, the manufacturer has equipped the NAD C298 with its HybridDigital Purifi Eigentakt technology, already used by the most high-end elements of its productions. Developed in collaboration with the Danish company Purifi, it gives the C298 exceptional dynamics combined with excellent frequency response linearity. The NAD C298’s connections are fairly conventional. Two pairs of terminals are dedicated to speaker connections, while the interconnection between the network player and the power amplifier can be made either via a conventional unbalanced cable on RCA sockets, or in balanced mode thanks to the presence of an input on XLR sockets.
Finally, for those of you who don’t want to be left without power, the NAD C298 can also be used as a mono power block. In this case, it develops power of up to 620 W at 8 ohms. In this case, of course, you’ll need to combine two C298 power units with the C658 network player for stereophonic reproduction.
The set up
It’s becoming more and more common to have to connect your sources to the network, but it’s rarer for this to be a preamplifier. At the same time, the C658 is much more than just a preamplifier. It’s also an excellent network player. If you want to keep strictly to a dematerialised configuration, you’ll essentially be using BluOS, which is probably the most successful application on the market for controlling your Qobuz, Tidal and many other subscriptions… However, if you wish, you can also connect your turntable equipped with an MM cell, or even two analogue sources, and a plethora of digital sources. As for the power block, we found it particularly unsaturated and capable of driving just about any type of loudspeaker. We carried out several tests with electrodynamic columns and isodynamic panels. In all cases, we were able to listen very loudly with impeccable control.
The sound
On paper, this set is particularly complete. It can be used as a source as well as an amplifier. And contrary to the old proverb ‘if you embrace too much, you embrace too little’, it combines universality with quality. When it comes to sources, first of all, we appreciated the C658’s flexibility. When BluOS is used, the result is excellent. The sound qualities of a Node 2i are there, with extra definition and energy on small signals. The sound is very stable, frank and nervous, and can be particularly demonstrative, but also delicate and subtle. We also tested Bluetooth aPTX with a Fiio portable music player. Here again, the C658 delivers confident, smooth and modulated streaming. Not so long ago, to get the same performance wirelessly, you had to pay three or four times as much. We’ve made significant progress in this area. We carried out cabling tests between the C658 and C298, and in the end we used a symmetrical link for all our tests. It gave us extra definition, gain and aeration of the soundstage.
As for the amplifier, we were able to measure the extent to which class D amplification has progressed in recent years. Until recently, the scenario was always the same: we were totally blown away during the first few minutes of listening, then somewhat disappointed afterwards. A bit like an unfulfilled promise. Today, the situation is very different. This NAD C298 equipped with the Purifi Eigentakt circuit delivers immense sonic satisfaction. The bandwidth is wide, allowing reproduction of a spectrum that ventures very low in the bass and rises very high in the treble. The tonal balance is not at all cartoonish, it’s completely natural. It’s even disturbing. And, of course, there’s always that quality of speaker control that’s unique to this type of amplification, and almost impossible to match. Of course, this amplifier offers a deliberately linear and neutral type of sound. There’s no trace of coloration or embellishment here, however elegant. The NAD C298 wants you to listen to the signal, just the signal, nothing but the signal. If you like your sound reproduced with a soft roundness, you won’t find much here. The warm subtleties of pure Class A won’t be there. The full-bodied midrange and gleaming treble of some American electronics are not on the agenda either. But if you appreciate purity without artifice, dynamics without any limitations, and deep, textured bass, you won’t be disappointed… Generally speaking, this NAD set provided us with long hours of uneventful listening, without the slightest question being asked. The audiophile, especially in reviewer mode, generally asks himself a multitude of questions… but I find it very reassuring that sometimes he takes a back seat and leaves room for the music lover who quietly enjoys his favourite pieces of music.
Our conclusion
Apart from a slightly utilitarian look (and even then, vintage is fashionable), there’s really nothing to criticise about this package, which does everything, and does it very well. The NAD C658 + NAD C298 package not only offers exceptional value for money, but also a level of intrinsic performance that is nothing short of exhilarating. Of course, there are more expensive, infinitely more expensive. There’s also much prettier. But when it comes to listening to music on a daily basis without any headaches, and especially with any loudspeaker, there isn’t much equivalent at this price.
Author: Unknown
Technical sheet: NAD C658 Network preamp/player
- Origin: Canada
- Price: €1,700
- Dimensions: 435 x 100 x 405 mm
- Weight: 10.1 kg
- Total harmonic distortion THD (20 Hz to 20 kHz): <0.005% (output voltage 1 V)
- Signal-to-noise ratio (SNR ): >110 dB (32 ohm loads; A-WTD, ref. 2 V out, unity gain)
- Frequency response: ±0.3 dB (20 Hz to 20 kHz)
- Channel separation: >60 dB at 1 kHz
- Output impedance: 6 ohms
Technical sheet: NAD C298 power amplifier
- Origin: Canada
- Price: €2,000
- Dimensions: 435 x 120 x 390 mm
- Weight: 11.2 kg
- Power: 2 x 185 W into 8 ohms – 2 x 340 W into 4 ohms
- Dynamic power: 260/490/570 W into 8/4/2 ohms
- Mono power: 620 W into 8 ohms
- THD: 0.0005
- Signal-to-noise ratio: >120 dB
- Channel separation: >110 dB (1 kHz)
- Frequency response: 20 Hz to 20 kHz (+/- 0.1 dB)
