Dual Mono topology with proprietary PowerDrive™ technology offers unparalleled audio performance
NAD, the highly regarded manufacturer of high-performance audio components, introduces the M3 Dual Mono Integrated Amplifier, one of the first four new components in the new Masters Series during the CEDIA Expo 2005 in Indianapolis this week.
The M3 not only looks solid and attractive in the new Masters Series’ luxurious industrial design, it offers unparalleled audio performance and features:
- Dual Mono design, featuring NAD’s proprietary Power Drive™ circuitry
- Ultra precise volume, balance and tone controls,
- Biamp output with selectable cross over frequency
- Output for additional amplifier or active subwoofer
- Seven inputs, including one balanced XLR
- Tape /Zone 2 output
- Custom installation features: RS-232 interface, 12 V triggers, IR outputs
“The M3 is NAD’s concept of the ideal musical companion, capable of transporting the listener to a place where the music exists in its own perfect space, “says Bob Brown, Chairman of NAD Electronics. “With some very sophisticated analog engineering, NAD has pushed classic analog circuit design to unprecedented levels of performance. ”
POWER AMP FEATURES
The M3 delivers 180 watts (x2) of continuous Full Disclosure Power with both channels driven into 8 or 4ohms, 20Hz — 20kHz, at less than 0.03% THD. It also carries a Dynamic power rating of 300 watts at 8 Ohms, 520 watts at 4 Ohms, and 700 watts at 2 Ohms.
It features a Dual Mono design with separate unregulated, and discrete regulated supplies for different stages of the 2 channels. The custom-made Holmgren transformers use proprietary magnetic shielding and custom windings to create a power supply that offers well-regulated voltage, and enormous amounts of current. High current rectifiers feed low ESR 105C filter capacitors. The Holmgren transformer design utilizes proprietary low leakage field technology resulting in low electrical noise (stray field) and physical noise (buzz).
NAD’s PowerDrive™ technology measures load impedance continuously on each channel and adjusts the power supply voltage for maximum undistorted dynamic power into the connected speaker at all times and under all operating conditions. The signal processor also continuously measures temperature and average long term power and, based on this information, chooses the optimum voltage.
PowerDrive allows the M3 to sound far more powerful than its already impressive 180-watt per channel rating would suggest. Totally effortless sound, even at elevated levels, is the hallmark of the PowerDrive amplifier.
The M3 utilizes a wideband current-mode Class A voltage amp featuring large open loop compensated bandwidth, and running from low noise stabilised power supplies. NAD’s patented current amp output stage starts with < 0.02 % static and dynamic distortion open loop (before feedback), even into 3 ohms at 20-20k at all levels. By utilizing small amounts of feedback the circuit returns distortion levels at all audible frequencies that are at limit of measurement -- less than 0.002%!
The super rugged output stage features 4 pairs of 150W discrete bipolar output transistors per channel, for 50A peak undistorted output current. Massive heat sinking assures a lifetime of trouble free operation.
PREAMP DESIGN
Freed of the constraints of traditional analog switches, NAD’s Director of Advanced Development, Bjorn Erik Edvardsen devised an architecture that eliminated the need for the audio signal to travel to the front panel for switching, as is common with traditional amplifier designs. The advantage of this architecture, in addition to its extremely precise performance, is the ability to place controls in the most advantageous physical position within the circuit, keeping signal paths as short as possible
The preamp uses discrete low noise, high impedance J-FET buffer amps and very high quality reed relay switches at the preamp input. Special high current low output impedance Class A gain modules provide tremendous dynamic headroom and high output current, combined with a exceptional S/N ratio in excess of -100dB (IHF).
The volume attenuator is unique in that it uses discrete 1% precision resistors with 0.5dB steps to keep impedance (and noise) extremely low. It has a range of 87.5dB. It is arrayed in 3 stages to reduce the residual noise in each amplifying stage. This circuit also provides the balance control with 0.5dB steps, and as a result channel separation is superb and inter-channel cross talk is virtually eliminated. These resistor arrays are switched using 15-volt digital switches under software control, keeping all attenuation at the ideal point in the circuit architecture.
Low impedance stepped tone controls provide +/- 5 db of boost/cut in the bass and treble regions, or can be configured to provide variable slope, or ‘spectrum tilt’ at +/- 3dB per decade.
The Bi-amp function allows the use of a second amplifier or active subwoofer (PreOut 2), and offers a high pass filter function on PreOut 1, with selectable 40Hz, 60Hz, 80Hz, 100Hz or Full Range options. These are analog 2nd order filters configured around the low impedance differential Class A output stage of the preamp. This output stage also employs proprietary distortion cancellation circuitry.
A balanced line input is also provided using identical JFET buffers feeding a discrete differential amp and yielding common mode rejection in excess of 80dB.
Separately regulated DC supplies are derived from the dual mono power supply. Copper buss bars and discrete regulators keep circuit noise to an absolute minimum throughout. The display and digital functions operate from an independent power supply to prevent any interference with the analog signal path.
“Build-Artistry™” and Master-Class Engineering
While others offer build quality The Masters Series delivers “Build Artistry™”. The M3 and all the other Masters Series Components are a result of many years of research by NAD’s product development team. The new Masters Series is the perfect balance of performance, value, style, flexibility, and ease-of-use, defining them as the best products in the company’s 33-year history and industry setting benchmarks.
From the smooth and precise action of the front panel controls to the elegantly proportioned remote handsets, every element of the design has been carefully considered for ease of use and clear logical operation. The new industrial design is solid and substantial, yet fresh and exciting. The look of the M3 visually reveals the dynamic performance capabilities contained within its sturdy forms.
The rugged chassis is built using thick 2mm mild steel plates with a front panel employing extruded aluminum and die-cast zinc in its construction. Special attention was paid to the control of mechanical resonance, as this can affect sonic performance. Special isolation feet use aluminum and silicon rubber in a vibration-damping configuration. All signal connectors are heavy duty gold plated types specifically engineered for the NAD Masters Series components. Finished inside and out, the M3 utilizes powder coating and advanced automotive paint finishes, creating an enduring and elegant mechanical package.
EASE-OF-OPERATION AND INSTALLATION
Unlike many high performance amplifiers, the M3 includes a full suite of convenience features such as speaker switching, flexible tone controls, and a Mode control that allows stereo, left only, right only, and mono settings.
The tone controls offer bass and treble adjustment, as well as a ‘spectral tilt’ option that is highly effective at correcting the tonal balance of many recordings by simultaneously increasing the bass and decreasing the treble (and vice versa) to create a warmer (or cooler) balance.
The front panel controls use a multi-function knob and buttons to quickly navigate all amplifier functions. All operating conditions are clearly displayed on the front panel. Direct access is available to many functions via the SRM 3 remote handset, which also features basic controls for the matching Masters Series M55 Universal CD/DVD player.
The M3 was supplied with a 12-volt trigger output and IR input/outputs for advanced theater installations. An RS-232 port, allows the M3 to be controlled by the most advanced control systems such as AMX and Crestron. There is also a Zone 2 output to control a separate set of speakers in another room. The Zone 2 has its own output with its own independent set of commands plus a dedicated ZR 3 remote control.
It’s time to get back in touch with the most elusive part of music-the emotional part. Experience sound quality that is more spirited and inspired. It’s an experience that equals or exceeds all performance benchmarks-regardless of price. The M3 Dual Mono Integrated Amplifier will ship in November 2005 with a US MSRP of $2,799. It can be seen with the rest of the Master Series components in Booth 214 during CEDIA Expo 2005.
