NAD Electronics C 298 Stereo Power Amplifier Evaluation

Jimmy Hughes tries the latest affordable Class D powerhouse from this legendary company …

NAD Electronics

C 298 power amplifier

£ 1,699 MSRP

NAD has long been known for budget esotericism – budget gear that gives enthusiasts a taste of the high end without the massive price tag. But maybe his reputation for value isn’t that helpful when the company is upscale and producing something more exotic and expensive?

Manufacturers of expensive esoteric items are likely to find it easier to move down than those on the lower end who are trying to move up. Not that the C 298 power amplifier and matching C 658 preamplifier are incredibly expensive. They’re both realistically cheap for what they offer.

For anyone in doubt, NAD has demonstrated its premium chops with the Masters component series. These offer luxurious build quality, advanced specs, and superior technology – albeit at a price. The C 298 is closer to the traditional NAD area and offers great performance and value for money.

The C 298 is a compact stereo power amplifier with one-sided and balanced inputs and a single set of speaker outputs and offers a conservatively rated output power of 185 W RMS per channel (or 620 W in bridged mono mode). Although it can be used with other preamps, its natural partner is the digital streaming preamplifier C 658. This was already enthusiastically reviewed by Andrew Baker for StereoNET in November 2019.

The C 298 has Purifi self-stroke technology. To quote NAD, “Purifi is a Danish technology company that has brought together several of the industry’s leading engineers to apply advanced mathematical models to solve the last remaining limitations of audio amplifiers. Although there are many great sounding amplifiers out there today, Purifi has re-examined every aspect of amplifier performance and found many seemingly small nonlinearities that can make a dramatic difference in the overall sound. “

NAD had previously used Purifi self-clock technology in some of its earlier, more expensive, high-end Masters power amps, but the C 298 offers this in a little less expensive. The company says it has “moved away from old-fashioned and power hungry class AB linear power supplies and power amplifiers, which use nearly half the power and not the sound. Instead, the company has developed even more powerful circuits based on switched-mode power supplies and class D power amplifiers. “

Mechanically and electronically, the C 298 is certainly very quiet. The technical data indicate an S / N ratio of> 120 dB at full power. I use sensitive speakers (99 dB / 1 W / 1 m) but couldn’t hear a hissing or humming noise even with one ear near the drive units. There is also no beep from the power transformer.

While the output power is conservatively at 185 W at 8 ohms, this power almost doubles to 340 W at 4 and a massive 620 W (8 ohms) available in bridged mono mode, while the peak power (mono mode) exceeds 1,000 W, which is a A pair of bridged power gives the C 298s enormous headroom. So it pays to buy a second C 298 and use a pair in bridged mode if you want to improve sound quality and / or performance. The result should be a bigger, heavier sound with increased scaling and dynamics.

The stated distortion is incredibly low, with a claimed THD of> 0.005% at full power. A frequency response of 20 Hz to 20 kHz within 0.2 dB and a -3 dB point of 60 kHz is specified. At least on paper, the C 298 is almost the proverbial “straight wire with reinforcement”!

Other useful functions are an input sensitivity pot on the back. So you can either operate the amplifier with normal (full) gain or switch to the variable option if that suits you better. I had the feeling that in the variable setting the sound might not be quite as clean, if not by much.

I used my C 298 along with NAD’s C 658 digital streamer preamp and selected the balanced XLR connectors for the best sound. The preamplifier has an optional automatic shutdown function that turns off the juice if no music is played for about half an hour.

The processing quality is high without being complex or extravagant. The overall finish is very good, but there isn’t any unnecessary opulence to leave you gasping for air. The C 298 and C 658 are definitely products for those who listen with their ears rather than their eyes!

It seems that there is some level of technology in common between these two and the more expensive Masters series M33. The latter are a little better, but not much better, which leads to speculation. You get much of what the M33 offers in terms of performance at a much cheaper price.

The C 658 offers a wide range of analog and digital inputs. There are two coaxial digital inputs, two optical TOSLINK digital inputs, a rear-mounted USB port (accessible via the BluOS app on a phone), two analog line inputs and an MM phono stage.

HEARING

The first impression on CD was a clean, solid and full-bodied musical presentation. Play the last DG Beethoven Triple concert with Mutter / Ma / Barenboim, the sound had fullness, weight and focus and seemed very clear without being bright or forward. However, was there a slight lack of air and openness – or was that what I imagined?

Compared to my reference amplifier Musical Fidelity Nu Vista 800, I subjectively felt the need to increase the volume slightly in order to create a comparable feeling of presence. The NAD combo seemed a bit “closed” by comparison, but the more I listened, the less it bothered me. The musical presentation seemed very true and correct to me – it’s difficult to put a few words, but me had a distinct impression of accuracy with nothing added or subtracted. I liked that.

Playback of the Chandos recording by Grechaninovs 1st symphony with Valeri Polyanskiand the musical presentation seemed smooth and relaxed while offering crisp, rapid transients and excellent clarity. The bass was solid and full, and the overall sound was clean and free of high-frequency glare and edges. Stereo sound staging was impressively vibrant and holographic. I really liked that the volume meter was displayed in decibels. That way, you can make precise adjustments for repeatable volume levels and always know where you are. The levels vary in steps of 0.5 dB, whereby subjectively uniform changes are achieved.

I was still listening to CDs, quickly playing with the tone controls and choosing a 1dB altitude lift. This helped open up the sound of Beethoven’s Triple a little, and I liked the effect. Since the C 658 has an MM phono stage, I tried it and the results were surprisingly good. I had to use a step up transformer as I was using a low power MC cartridge. Sonically the results were excellent – as if I were using a good outboard phono stage. Only the lack of a suitable high gain MC input is a limitation.

Play again Keith Jarrets Standards Vol 1 on ECM vinyl, I sometimes missed a slight lack of gloss and vibrancy at higher frequencies. It was by no means serious; just a little more prudent and controlled. But when I switched to streamed or downloaded material, the sound suddenly got a lot livelier.

With my normal system, I use a Chromecast device for services like Spotify and TIDAL, and it always seemed perfectly fine. But play the old HMV Mahler 5 With Sir John Barbirolli at Warner, I heard a really big improvement on the C 658 – a much sharper, more focused sound with amazing detail. I definitely no longer needed this 1 dB altitude lift!

The preamp’s built-in DAC made my hotch-potch connections a lot easier, and provided redundancy notifications for various separate DACs – a bit like the hi-fi equivalent of those credit deals that let you consolidate all of your card debt onto a single card for one simple, easy payment! While the C 658 offers a sleek one-box solution for those of us with too many sources, the improved sound quality with both downloads and streamed sources was really impressive. Personally, I still like Compact Disc as a medium, but the format has limitations.

High definition downloads really demonstrate the full sonic capabilities of the C 658 / C 298. The sound has better bite and definition, and things seem sharper and more immediate. At the same time, I could still feel that “nothing was added or subtracted” that I had previously admired.

THE JUDGMENT

This reasonably affordable NAD combo adds very little of its own signature. It can sound both sleek and frugal, or rich and opulent – it’s mainly the type of recording being played, not something the electronics add to it. Undoubtedly some are put off by prejudice against Class D, but listen openly and I am sure you will like what you hear.

The C 298 power amplifier is compact, quiet, powerful, efficient, environmentally friendly and sounds great. Together with the C 658 Streaming Pre, it’s an impressive combination that I could certainly live with. Because of its versatility and excellent sound, I wonder how long I could keep my Musical Fidelity Nu Vista 800. While I’m not ready to get rid of it yet, its days may soon be numbered …

See NAD Electronics for more information

Comments are closed.