• WANTED: Happy members who like to discuss audio and other topics related to our interest. Desire to learn and share knowledge of science required. There are many reviews of audio hardware and expert members to help answer your questions. Click here to have your audio equipment measured for free!

NAD C298 Stereo Amplifier Review

Rate this amplifier:

  • 1. Poor (headless panther)

    Votes: 3 1.1%
  • 2. Not terrible (postman panther)

    Votes: 32 11.7%
  • 3. Fine (happy panther)

    Votes: 137 50.0%
  • 4. Great (golfing panther)

    Votes: 102 37.2%

  • Total voters
    274

amirm

Founder/Admin
Staff Member
CFO (Chief Fun Officer)
Joined
Feb 13, 2016
Messages
44,850
Likes
243,419
Location
Seattle Area
This is a review and detailed measurements of NAD C298 stereo class D power amplifier based on Purifi Eigentakt modules. It is on kind loan from a member and costs US $2,399.
NAD C298 Purifi stereo balanced amplifier review.jpg

The unit is quite heavy for a class D amplifier. The front is plain as most power amps are. I was not a fan of the status LED. On power up, it turns orange. If you hit the power button, it initially goes red making you think there is a fault. But eventually switches to blue saying it is on. Back panel shows some nice features such as fixed and variable gain and selectable level for trigger input (auto power on):
NAD C298 Purifi stereo balanced amplifier back panel xlr RCA review.jpg

I realize NAD reserves their exquisite casing for their "Master" series but if I am paying $2,400 for an amplifier, I expect something better than stamped sheet metal cover and utilitarian binding posts. FYI the vents on top are only on top of one amp heatsink and not the other. Seemingly they went for looks rather than usefulness there.

NAD C298 Amplifier Measurements
I started measuring with fixed gain and was pleased to see the gain close to our nominal 29 dB:
NAD C298 Purifi stereo balanced amplifier Fixed Gain measurement.png

Distortion is vanishingly low at -120 dB and it is noise that brings it down to a very respectable 100 dB SINAD:
best stereo amplifier review.png


best stereo amplifier zoom review.png


I was hoping to get even better performance by lowering the gain to 15 dB. That did not happen:
NAD C298 Purifi stereo balanced amplifier Variable Gain measurement.png


We actually have more distortion and some mains noise as well! :( So back to fixed gain for the rest of the tests. Here is RCA input:
NAD C298 Purifi stereo balanced amplifier Fixed Gain RCA measurement.png


Dynamic range is excellent:
NAD C298 Purifi stereo balanced amplifier Fixed Gain dynamic range measurement.png


NAD C298 Purifi stereo balanced amplifier Fixed Gain dynamic range max power measurement.png


Multitone distorting is very low but with some increase at higher frequencies:
NAD C298 Purifi stereo balanced amplifier Fixed Gain Multitone measurement.png


Which is reflected in dual 19 and 20 kHz tones:
NAD C298 Purifi stereo balanced amplifier Fixed Gain 19 20 kHz measurement.png


Frequency response is flat and load independent which is great:
NAD C298 Purifi stereo balanced amplifier Fixed Gain frequency response measurement.png


Crosstalk is excellent:
NAD C298 Purifi stereo balanced amplifier Fixed Gain crosstalk measurement.png


Let's see how much power we have:
NAD C298 Purifi stereo balanced amplifier Fixed Gain power 4 measurement.png

That's quite healthy and gets even better if we allow 1% THD:
NAD C298 Purifi stereo balanced amplifier Fixed Gain max and peak power 4 measurement.png


No, I didn't test the bridge mode. Stereophile did and it does pump out a ton of power.

Here is the 8 ohm power:
NAD C298 Purifi stereo balanced amplifier Fixed Gain power 8 measurement.png


Sweeping with different frequencies shows unhappiness only when frequencies go above 5 kHz:
NAD C298 Purifi stereo balanced amplifier Fixed Gain power vs frequency measurement.png


Power on is silent although there is a pattern in the idle noise which should have been caught and eliminated:
NAD C298 Purifi stereo balanced amplifier power on off pop noise measurement.png

My target here is 1 mv and it is exceeded when unit is powered off so that may cause a pop.

The amplifier is stable on power up but has the same strange variable pattern:
NAD C298 Purifi stereo balanced amplifier warm up measurement.png


Conclusions
If you want an amplifier with state of the art class D module in it, your choices are usually from smaller independent companies. NAD is one of the exceptions in major brands to offer an amplifier with Purifi module in it. That comes at a premium in retail cost due to channel and brand overhead. The C298 delivers excellent performance with just some minor issues in variable gain and idle noise.

I am going to put the NAD C298 on my recommended list. But if I were you, I would cut back on eating out for a couple of years and save money to get the beautiful master series. :)

Manufacturers Specifications:​

ANALOG AUDIO INPUT/LINE OUT​

  • THD (20 Hz – 20 kHz)
  • <0.0005 % at 2V out
  • Signal-to-Noise Ratio
  • >120 dB (IHF; 20 Hz – 20 kHz, ref. 2V out)
  • Channel separation
  • >110 dB (1 kHz)
    >100 dB (10 kHz)
  • Input impedance (R and C)
  • Single-ended: 56 kohms + 280 pF
    Balanced: 56 kohms +280 pF
  • Maximum input signal
  • >7.0 Vrms (ref. 0.1 % THD)
  • Output impedance
  • 390 ohms
  • Frequency response
  • ±0.1 dB (20 Hz – 20 kHz)
  • Maximum voltage output -IHF load
  • ≥>7.0 V (ref. 0.1 % THD)

ANALOG AUDIO INPUT/SPEAKER OUT​

  • Rated output power into 8 Ohms and 4 ohms (Stereo mode, ref. 20 Hz-20 kHz at
    rated THD, both channels driven)
  • 185 W at 8 ohms
    340 W at 4 ohms
  • Rated output power into 8 Ohms
    (Bridge mode, ref. 20 Hz-20 kHz
    at rated THD, both channels driven)
  • 620 W at 8 ohms
  • THD (20 Hz – 20 kHz)
  • <0.005 % (1 W to 185 W, 8 ohms and 4 ohms)
  • Signal-to-Noise Ratio
  • >98 dB (A-weighted, 500 mV input, ref. 1 W out in 8 ohms)
    >120 dB (A-weighted, ref. 185 W out in 8 ohms)
  • Clipping power (Stereo mode, at 1 kHz 0.1 % THD)
  • >200 W
  • Clipping power (Bridge mode, at 1 kHz 0.1 % THD)
  • >690 W
  • IHF dynamic power (Stereo mode, at 1 kHz 1 % THD)
  • 8 ohms: 260 W
    4 ohms: 490 W
    2 ohms: 570 W
  • IHF dynamic power (Bridge mode, at 1 kHz 1 % THD)
  • 8 ohms: 1000 W
    4 ohms: 1100 W
  • Peak output current
  • >25 A (in 1 ohm, 1 ms)
  • Damping factor
  • >800 (ref. 8 ohms 20 Hz – 6.5 kHz)
  • Frequency response
  • ±0.2 dB (20 Hz – 20 kHz)
    -3 dB at 60 kHz
  • Channel separation
  • >100 dB (1 kHz)
    >80 dB (10 kHz)
  • Stereo Mode input sensitivity (for 185 W in 8 ohms)
  • Fixed Gain mode: 1.43 V
  • Stereo Mode Gain
  • Fixed Gain mode: 28.6 dB
  • Line In – Balanced and Single-ended
  • Variable Gain mode: 8.5 dB – 28.5 dB
  • Bridge Mode Sensitivity
  • Fixed Gain mode: 3.78 V for 620 W in 8 ohms
  • Line In – Balanced and Single-ended
  • Variable Gain mode at maximum: 1.41 V for 620 W in 8 ohms
  • Bridge Mode Gain
  • Fixed Gain mode: 25.4 dB
  • Line In – Balanced and Single-ended
  • Variable Gain mode: 14.5 dB – 34.5 dB
  • Standby power
  • <0.5 W

DIMENSION AND WEIGHT​

  • Gross dimensions (W x H x D)
  • 435 x 120 x 390 mm (17 1/8 x 4 3/4 x 15 3/8 inches)
  • Net weight
  • 11.2 kg (24.7 lbs)
  • Shipping weight
  • 13.6 kg (30 lbs)

-----------
As always, questions, comments, recommendations, etc. are welcome.

Any donations are much appreciated using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/
 
Last edited by a moderator:

ahofer

Master Contributor
Forum Donor
Joined
Jun 3, 2019
Messages
5,104
Likes
9,292
Location
New York City
I bought one second hand from a member here some months ago. It works great, only the slightest tick when it auto-powers on. An abundance of power for my purposes (Harbeth SHL5+AE).
 

martijn86

Active Member
Joined
Aug 30, 2019
Messages
278
Likes
996
Location
The Netherlands
It's surprising that not many big brands use off the shelf Hypex/Purify boards. NAD doesn't really offer anything extra with this amplifier but going for a straight forward Power Amplifier, all they had to do is not mess it up and they done a good job with that. Probably a nice combination with a streaming DAC from the C series.

Now Topping should destroy all of the competition and put two bridged LA90D's in one case with build-in power supply.
 

martijn86

Active Member
Joined
Aug 30, 2019
Messages
278
Likes
996
Location
The Netherlands
Why buy this when we have plenty of Purifi implementation with cleaner power, and probably better case? Maybe except the brand and retailer network?
Warranty? Trusted sellers? Resell value? Quality control? Matches the rest of your equipment stack?

I'm making up excuses here because I'm really happy with Audiophonics' Hypex implementations. Other than the fact that the large case is rather deep so I use right angle connectors for everything in the back, I wouldn't spend NAD money on it.
 

TK750

Active Member
Joined
Apr 19, 2021
Messages
226
Likes
415
Location
UK
Why buy this when we have plenty of Purifi implementation with cleaner power, and probably better case? Maybe except the brand and retailer network?
Personally I'd definitely go for a boxem/audiophonics/buckeye/nord...etc. However I suppose the larger established brand name and availability in brick and mortar stores etc is perhaps preferable to some people. If anything goes wrong it's much easier to just drop it off at your local shop than ship it to whichever manufacturer/country is necessary out of the previously mentioned. I'm not suggesting any of the aforementioned wouldn't provide good customer service or honour warranty but I can understand a more established name with in store presence giving some customers that little bit more confidence.
 

pogo

Major Contributor
Joined
Sep 4, 2020
Messages
1,372
Likes
467
Why buy this when we have plenty of Purifi implementation
Bridge mode, matched purifi modules, dynamic output power (see also here: Link), ...
NAD does not use any off-the-shelf purifi modules, but rather modules produced and matched 'in-house'. Matched modules are necessary for the bridge mode to work properly!
 
Last edited:

martin900

Active Member
Joined
Jan 31, 2020
Messages
161
Likes
184
Good performance, good price, worthless reliability, sadly. If you buy them new, sell after 5 years no matter what.
 

ahofer

Master Contributor
Forum Donor
Joined
Jun 3, 2019
Messages
5,104
Likes
9,292
Location
New York City
Good performance, good price, worthless reliability, sadly. If you buy them new, sell after 5 years no matter what.
Has the C298 even been out for 5 years? The first reviews are in 2021. It was released in October 2020. On what do you base your assertion?
 

Sokel

Master Contributor
Joined
Sep 8, 2021
Messages
6,357
Likes
6,497
1.7K for peace of mind,warranty,after sale service,good reselling value and top performance is nor bad at all.
But the big brother's nicer case worth the premium 100% ,Amir is right.

Thanks for the review!
 

MyCuriosity

Member
Joined
Jan 25, 2023
Messages
85
Likes
44
I think this one is available for demo in my dealer. I will definitely give it a go and listen some music with this amp in the chain. Who knows, it might be the first class D amplifier I might actually like. Even though the price is a bit steep for a class D amplifier. Fine amp from measurements point of view
 

Dougey_Jones

Addicted to Fun and Learning
Forum Donor
Joined
May 27, 2020
Messages
555
Likes
467
Bad price/performance ratio, and mid-fi aesthetics. If you're willing to go the Hypex/Bruno route, you can get more power in a better/cleaner implementation for literally half the price.
 
Last edited:

Silly Valley

Member
Forum Donor
Joined
Feb 11, 2019
Messages
28
Likes
46
Location
Silicon Valley
The case is fine in the $1500 less expensive C268. For $2400, many might expect better. But it is in keeping with the NAD entry level line cases.

Yes, for about half the price, several sellers frequently mentioned here get you Purifi. I think this may mostly appeal to those with NAD classic series in the rack or wanting traditional size components available locally. Even for those folks, it mat be a tough sell at current retail pricing.
 

phoenixdogfan

Major Contributor
Forum Donor
Joined
Nov 6, 2018
Messages
3,364
Likes
5,337
Location
Nashville
That Purifi 1ET400A module seems to be at the heart of every highly acclaimed amp released in the last 3-4 years. I was glad to be a pioneer in assembling an Eval1 amp from the Purifi module, a Ghent case, and the Hypex Smps 1200 A700A. I've found it to be the most transparent amp I've ever used in any of my systems. IDK, if NAD is using all the same components as the original Eval 1 Amir reviewed way back when, but given what they're starting with, as long as they didn't do anything to screw it up, it's really no surprise it's measuring as well as it is.

Obviously any buyer is paying a premium for the nice case, the professional assembly, and the reputation a big name high end audio company like NAD has for properly engineering and standing behind their products. Anyone with that set of buyer requirements would probably find the price reasonable. In any case, they'll certainly be getting a highly performant amplifier.
 

Dougey_Jones

Addicted to Fun and Learning
Forum Donor
Joined
May 27, 2020
Messages
555
Likes
467
Obviously any buyer is paying a premium for the nice case, the professional assembly, and the reputation a big name high end audio company like NAD has for properly engineering and standing behind their products.
This is the problem though. The internal wiring and connectors used are low quality (push/crimp), the case is mid-fi, the binding posts are bottom of the barrel, and the execution is subpar (noise) otherwise it would've benched better. This is a simple stereo implementation we're talking about, in a roomy case.
 
Top Bottom