HybridDigitalTM Purifi EigentaktTM Amplifier

In the company's almost 50-year history, NAD has debuted numerous innovative amplifier technologies – starting with the classic 3020 with its enormous current delivery capability, right up to the Class D flagship M2. In August 2020, the NAD M33 was released, a brand new high-end streaming integrated amplifier that uses the innovative new Purifi EigentaktTM technology for the first time worldwide and was promptly awarded the EISA Award as best "Smart Amplifier 2020/21".
With the new C 298 stereo power amplifier, NAD aims to make the unique Purifi EigentaktTM amplifier technology accessible to a wider audience. It is the perfect companion for the BluOS streaming preamplifier C 658 and impresses with enormous power.
Purifi is a Danish technology company where some leading developers in the hi-fi industry aim to identify and eliminate the last remaining weaknesses in digital amplifier technology. The current state of their work resulted in the Purifi EigentaktTM amplifier, which NAD is the first company to license and has so far exclusively used in the BluOS streaming amplifier M33.
The Purifi EigentaktTM technology impresses with extremely low intermodulation distortion, a particularly low total harmonic distortion of only 0.005% over the entire frequency range and the complete power bandwidth, as well as minimal inherent noise.
Pivotal for the development of EigentaktTM technology was the realization that a memory effect occurs in the components in the output filter of the amplifier. This phenomenon, known as hysteresis, evidently leads to the known sonic degradation of conventional digital amplifiers. By modifying the output stage and using the clever algorithms of Eigentakt technology, Purifi succeeded in significantly reducing hysteresis effects. Another advantage of the EigentaktTM power amplifiers is that they are absolutely immune to changing speaker loads. Their extremely low output impedance also leads to a very high damping factor, which results in an absolutely clean and controlled bass reproduction.

Enormous Power Reserves

Instead of old-fashioned linear power supplies and Class AB amplifiers, which convert almost half of the required energy into heat instead of power, NAD only uses switching power supplies and Class D power amplifiers in its current amplifiers. This design works very linearly over a wide range and offers consistent performance to all speaker loads, which represents a dramatic improvement over earlier techniques.
The generously dimensioned power supply of the C 298 allows the power amplifiers an enormous continuous power of 2 x 340 watts (into 4 Ω) and up to 2 x 570 watts of impulse power (into 2 Ω). The innovative asymmetric PowerDrive technology uses every available watt to provide enormous dynamic reserves to reproduce music precisely without distortion or compression. In addition, the highly efficient power supply impresses with nearly perfect voltage regulation over its entire operating range, ensuring a solid, noise-free power supply for the amplifier stages.

Key Features

HybridDigitalTM Purifi EigentaktTM Amplifier
Continuous output power: 2 x 185 W into 8 Ω, 2 x 340 W into 4 Ω
Impulse power: 2 x 260 W / 2 x 490 W / 2 x 570 W (into 8/4/2 Ω)
Impulse power in bridge mode: 1,000 W into 8 Ω, 1,100 W into 4 Ω
Balanced XLR inputs
Gold-plated RCA inputs
Adjustable input level
High-level output for looping through the audio signal to other power amplifiers
Inputs and outputs for 12 V trigger signals
Adjustable sensitivity for automatic power-on
Inputs and outputs for IR
Ground terminal
Separate power cable

Flexible Application Possibilities

The C 298 may at first glance appear to be a simple stereo power amplifier, but NAD engineers have carefully considered all applications to develop a power amplifier that is as universally applicable as possible. For example, the C 298 has balanced inputs, making it suitable for professional studio use and connection to high-end preamplifiers and processors. Thanks to its variable input sensitivity, the C 298 can be perfectly integrated into constellations with other amplifiers or active speakers and subwoofers – the required high-level preamplifier output is already part of the equipment package. An auto power-on function with adjustable sensitivity simplifies the operation of complex systems and allows for hidden operation of the amplifier. The ground terminal prevents ground loops and hum disturbances in audio systems with multiple amplifiers. And finally, if required, the C 298 can also be operated in bridge mode, which turns it into an astonishingly powerful monoblock amplifier. Start with one C 298 and add a second later when you upgrade your speaker system.
Fundamental Requirements
It is astonishing how many seemingly advanced products on the market today often do not even meet the basic requirements for reliable and good-sounding operation. NAD, on the other hand, understands the importance of low-noise circuitry, precise channel balance, correct input and output impedance characteristics, large headroom, and stable amplification even with difficult speaker loads. NAD's engineers consider these fundamental aspects in their work and continuously develop them further.
For example, the high-level inputs of the C 298 – whether the balanced XLR or the conventional RCA jacks – are suitable for all types of analog audio sources, as they feature an ideal input impedance with linear, extremely low-noise buffer amplifiers to prevent sonic degradation due to impedance mismatch. Details that you can hear.

Analog Input to Loudspeaker Outputs

Continuous output power in stereo mode into 8 Ω
2 x 185 W (20 Hz – 20 kHz at rated THD)

into 4 Ω
2 x 340 W (20 Hz – 20 kHz at rated THD, into 4 Ω)

Continuous output power in bridge mode
1 x 620 W (20 Hz – 20 kHz into 8 Ω)

Dynamic power in stereo mode (at 1% THD, 1 kHz, into 8 Ω)
2 x 260 W

into 4 Ω
2 x 490 W

into 2 Ω
2 x 570 W

Total harmonic distortion (20 Hz – 20 kHz)
<0.005% (1 to 185 W into 4 and 8 Ω)

Signal-to-noise ratio (A-weighted)
98 dB (500 mW input, 1 W output into 8 Ω); >120 dB (185 W output into 8 Ω)

Damping factor
800 (8 Ohms, 20 Hz – 6.5 kHz)

Input sensitivity (for 185 W into 8 Ohms)
1.43 V

Frequency response
±0.2 dB (20 Hz – 20 kHz), -3 dB (60 kHz)

Analog Input to Line Output

Total harmonic distortion (20 Hz – 20 kHz)
<0.0005% at 2 V output level

Signal-to-noise ratio (A-weighted)
120 dB (IHF, 20 Hz-20 kHz, at 2 V output level)

Input impedance (R and C)
RCA and XLR: 56 kΩ + 280 pF

Maximum input level
7.0 V (at 0.1% THD)

Output impedance
390 Ω

Frequency response
±0.1 dB (20 Hz – 20 kHz)

Maximum output voltage
7.0 V (at 1% THD)

General

Standby power consumption
<0.5 W

Dimensions (W x H x D)
435 x 120 x 390 mm

Weight
11.2 kg

• 298 in stereo

DALI GmbH
Berliner Ring 89, 64625 Bensheim, DE
support@nadelectronics.com
https://www.nadelectronics.com