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.
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):
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:
Distortion is vanishingly low at -120 dB and it is noise that brings it down to a very respectable 100 dB SINAD:
I was hoping to get even better performance by lowering the gain to 15 dB. That did not happen:
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:
Dynamic range is excellent:
Multitone distorting is very low but with some increase at higher frequencies:
Which is reflected in dual 19 and 20 kHz tones:
Frequency response is flat and load independent which is great:
Crosstalk is excellent:
Let's see how much power we have:
That's quite healthy and gets even better if we allow 1% THD:
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:
Sweeping with different frequencies shows unhappiness only when frequencies go above 5 kHz:
Power on is silent although there is a pattern in the idle noise which should have been caught and eliminated:
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:
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.
-----------
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/
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):
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:
Distortion is vanishingly low at -120 dB and it is noise that brings it down to a very respectable 100 dB SINAD:
I was hoping to get even better performance by lowering the gain to 15 dB. That did not happen:
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:Dynamic range is excellent:
Multitone distorting is very low but with some increase at higher frequencies:
Which is reflected in dual 19 and 20 kHz tones:
Frequency response is flat and load independent which is great:
Crosstalk is excellent:
Let's see how much power we have:
That's quite healthy and gets even better if we allow 1% THD:
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:
Sweeping with different frequencies shows unhappiness only when frequencies go above 5 kHz:
Power on is silent although there is a pattern in the idle noise which should have been caught and eliminated:
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:
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:
