M28

Seven Channel Power Amplifier

The Masters M28 Seven Channel Power Amplifier epitomises the ultimate in what is possible with today’s amplification techonology. It is one of the very first amplifiers to employ Purifi’s Eigentakt™ amplifier technology.

Rated conservatively at 200W per channel (8 ohms) and well over 320W dynamic power (8 ohms; all channels driven), the result is breath-taking, lifelike surround sound performance, be it from the latest action-packed film with tremendous dynamics or a subtle classical piece with delicate and detailed passages. The M28 can accept both balanced and single-ended inputs, and features high-quality binding posts for speaker connection. The compact dimensions of this highly energy-efficient design belie the massive amount of power available for the most demanding music and movies.

Completely immerse yourself in the moment with Purifi™.

Purifi Eigentakt Amplification

The Masters M28 uses Eigentakt™ amplifier technology, manufactured by NAD in license from Purifi. This new technology, which NAD was the first to embrace for the M33 Masters Series Streaming Amplifier, adds another level of precision by taking into account previously unknown effects of the output filter in the feedback loop and further refinement of the self-oscillating Class D technology as used by previous NAD Hybrid Digital designs. The result is a performance level that approaches the theoretical limit in measured performance, be it at whispering levels or at full power.

In common with the previous generations of NAD Hybrid Digital technology but unlike most class D amplifier designs, the M28 is impervious to the loudspeaker load it is presented with, maintaining the same wide and even bandwidth response irrespective of the speaker’s impedance and at the same time providing high current capability. The continuous 200W into 8 ohms on tap for all channels driven at the same time and 700W dynamic power into 4 ohms is testament to this.

Inherent to the Eigentakt™ technology is its very analogue-like behaviour in the unlikely event the amplifier is driven into clipping. Whereas many class D designs can become unstable, Eigentakt™ behaves in a way similar to the benign way of clipping with instant recovery of well executed traditional class A/B amplifiers.

The sonic character of the M28 only reinforces the story told by the numbers. This is an amazingly powerful and transparent amplifier bringing new levels of refinement and dynamics at any level.

Fully Balanced Audio

The same efficient audio interface used by studios provides the highest level of signal integrity with the lowest noise floor.

Locking connectors and special interface electronics allow long cable runs without noise pickup or signal loss. All you get is awesome sound without the possibility of noise pickup or interference.

Effortless Power

As our most powerful amplifier ever, the M28 can pump out over 700W into difficult loads to follow complex dynamic peaks in your movies and music. Everything from rim shots to asteroid explosions sound remarkably real and immersive.

The M28 has power reserves to meet the demands of the latest high-resolution digital soundtracks. Thanks to the advanced Purifi Eigentakt™ amplifier technology, all this monster power comes at a lot less cost than traditional technology and delivers more power and performance!

OVERALL SPECIFICATIONS

FTC power, two channels

≥ 220 W (ref. rated THD, 8 Ohms , 20 Hz – 20 kHz, two channels driven)
≥ 400 W (ref. rated THD, 4 Ohms , 20 Hz – 20 kHz, two channels driven)

Rated power, all channels

≥ 200 W (ref. rated THD, 8 Ohms , 20 Hz – 20 kHz, all channels driven)
≥ 340 W (ref. rated THD, 4 Ohms , 20 Hz – 20 kHz, all channels driven)

Rated THD (250 mW to rated power, CCIF IMD, DIM 100)

≤0.003 % (ref. 20 Hz – 20 kHz)

IHF dynamic power

280 W 8 Ohms, (all channels driven)
560 W 4 Ohms, (one channel driven)

Damping factor

1.3 V (ref. rated power)

Input impedance
Input Impedance (r and c)

47 kΩ (Balanced)
23 kΩ (Single-ended)

>118dB (ref. rated power)

Damping Factor

>750dB (ref. 8 Ohms, 50Hz and 1kHz)

Frequency Response

±0.1dB (ref. 20Hz-20kHz)

-2.5dB at 3Hz and 100kHz

Input Impedance

47 kilohm (Balanced)

Signal/noise ratio

> 102dB (A-weighted ref. 1W, Balanced)
> 97 dB (A-weighted ref. 1W, Single-ended)
> 124 dB (A-weighted ref. rated power, Balanced)
> 120 dB (A-weighted ref. rated power, Single-ended)

Frequency response

± 0.1 dB (ref. 20 Hz – 20 kHz)
– 3 dB at 3 Hz to 60 kHz

Time to go to Standby mode at no input signal

≤ 30 minutes

Standby power

≤ 0.5W