State-of-the-Art Monaural Amplifier

The highest sound quality at all volume levels, flat frequency response into any load, and stable into the most difficult loads. The Statement M1 is a state-of-the-art monaural amplifier delivering 1,000 watts into 8 ohms and 2,000 watts into 4 ohms or less with THD remaining under 0.1% from 20 Hz to 20 kHz. Designed and engineered in our advanced research center in Ottawa, Canada, the M1 is manufactured in our Toronto facility.

More than just a slim, technologically advanced monaural design, the M1 demonstrates that Class D architecture isn't fundamentally flawed, it simply hasn't been implemented well in the past, mainly because it required such a heavy commitment to R&D. We’re fortunate to have the in-house resources to create such a groundbreaking product and one listen will reveal the truly extraordinary nature of this amplifier.

Cutting Edge Technology & Design

• Full resolution of all of the sonic subtleties and complexities in the input signal.
• Accurate reproduction of the full dynamic range of the signal.
• Output stage is never allowed to clip.
• No compression as output increases.
• Flat frequency response into any load, without having to resort to digital conversion or equalization to compensate.
• Stable into all loads including open circuit and short circuit.

• A low noise floor.
• Exceptional efficiency with low heat output.
• An amp so mechanically silent it will suit even the quietest listening room.
• A design that allows multiple units to be stacked with no danger of overheating.
• All of the above delivered at a price point that while not inexpensive, delivers virtually limitless dynamic fidelity.

Best Value in the Market

The M1 enjoys all of the attributes of our award-winning Statement Class AB amplifiers but through exclusive Anthem technologies, goes far beyond the current capabilities of Class A, Class AB and prior Class D amplifiers in the market.

The proprietary design employs all of the advantages of a Class D amplifier — high output, high efficiency, compact size — while avoiding the typical Class D limitations such as difficulty driving low-impedance (high-end) speakers, power line contamination, reliability issues and substandard audio quality. The absence of accurate dynamics is so common that it frequently goes unnoticed, but through the M1, music and movies are delivered with breathtaking realism.

POWER!

2,400W into 3 ohms

2,000W into 4 ohms

1,000W into 8 ohms

* These figures are continuous from 20 Hz to 20 kHz at less than 0.1% THD+N. The M1 can deliver 2 kW continuously when fed by 240V mains and 2 kW for several seconds when fed by a dedicated 120V 15A line.

Slim Size, Beefy Power!

Never judge an amp by its size or its rack space

Amplifiers are often judged by their size and weight, the beefier the better since more power requires a physically heavier, larger amplifier. Or does it? It all depends on the design. When rack-mounted, the 20-kb M1 occupies only one rack space but despite its size can deliver 1,000W into 8 ohms and 2,000W into 4 ohms.

Cool running

The M1’s cooling system quickly and efficiently moves heat from the interior of the amplifier to exterior heat sinks. Sealed copper pipes within the amp contain a small amount of special fluid held under a vacuum. When the temperature at one end of the pipe rises — the end adjacent to the amplifier's heat sources — the fluid in that end evaporates. This vapor is then naturally drawn to the cooler end of the pipe, along the heat sink on the side of the amp’s chassis where it condenses. From there a copper wick returns the fluid to the hotter end of the pipe. This heat transfer process is many thousands of times faster and more efficient than cooling through metal heat sinks alone. This system eliminates the need for fans, allowing multiple M1s to be stacked with no danger of overheating. It also means the amplifier is so mechanically quiet it will suit even the quietest listening rooms.

No noise is good news

With an absence of noisy fans and a noise floor well below that of a high-end preamplifier, the M1 is a critical listener's dream.

Advanced Load Monitoring & Power Factor Correction

Proprietary Load Monitoring

The M1 has a very sophisticated load monitoring system. Two 100A Hall-Effect sensors monitor the output current. A Digital Signal Processor, outside the signal path, is used for power sequencing and to monitor various amplifier and power supply functions including line voltage, output current, ground fault detection, temperature and DC voltage at the output.

The M1’s output stage does not interact with the load. A hysteric PID controller which uses past, present and a predicted future to make adjustments keeps the amp load independent. Hundreds of computer simulations were used to test and optimize this system so that it is able to handle all possible loads. This is a significant design achievement. Whether you are running the M1 from a 120V circuit or a 240V circuit, the amplifier will be delivering the highest output possible according to the operating conditions.

Left: Power supply without PFC. Current flows in short bursts and ends up much higher than it needs to be, limiting available power and increasing the chance of tripping a breaker.

Right: Power supply with PFC. The voltage and current waveforms are sinusoidal and in-phase.

Power Factor Correction

Power Factor Correction (PFC) maximizes available power and at the same time reduces (by a large amount!) the noise put on the AC line. Without PFC, the input current can flow and charge the capacitors only during the short moments that voltage is at or very close to its positive or negative peak. Since power is the product of both voltage and current it is produced only when both are present. Power Factor Correction marries the voltage and current cycles enabling continuous output from the power supply through the entire AC cycle. In doing so, the load appears almost purely resistive to the AC source. (See diagrams to right)

The special advantages of bridged mode amplification in the M1

• Lower voltage MOSFETs can be used for lower resistance and higher speed. Although more expensive since more MOSFETs are needed, sound quality is vastly improved.
• Because the load is balanced, output current goes from one rail to the other without disturbing the ground plane. A balanced load also provides more efficient use of the power supply. Rail voltage is stable, unlike in single-ended Class D amps which suffer from rail pumping at low frequency and high power.
• Power supply capacitors become more efficient because bridging doubles the ripple frequency while impedance and ripple voltage are halved, allowing the power supply capacitors to be more efficient.
• For a high-power amp such as the M1, bridging can be safer. The differential output voltage can reach over 90 Vrms but at this level each output terminal is only 45 Vrms with respect to the chassis.

Additional high-end touches

• Hand-designed 4-layer FR4-rated glass-epoxy circuit board with 2-ounce copper traces promotes exceptional conductivity.
• Extensive use of power and ground planes ensures vanishingly low levels of noise and inductance to produce an amp that gets out of the way, leaving only the sound of the music.
• Each of the eight 65-amp MOSFETs can handle a peak current of 260 amperes, has low gate charge for fast response, low channel resistance for high efficiency and high speed for high efficiency and low distortion.
• No relays are used in the signal path preventing any possibility of relay failure.

Inputs

RCA, XLR and Trigger

Outputs

Trigger and Binding Post

Auto-on

The M1 can be set to power on/off via trigger or by sensing an input signal. After a few minutes with no signal it will turn off automatically.

Not all Class D amplifiers are created equal!

In the audio press and across the Internet many generalizations have been made about deficiencies in Class D amplifier design. While such generalizations may hold true for other brands of amplifiers, below, Anthem responds to each one as it relates to our M1.

Generalizations:

The odds are stacked against the Class D amp designer.

The M1 Response:

There’s nothing like a challenge to get Anthem designers and engineers working far into the night!

Class D amps have high radio-frequency emissions.

Emissions are well within EMC Class B requirements. Class B requirements apply to residential use and are far stricter than Class A requirements.

Frequency response is affected by input circuits that are highly sensitive to stray high frequency signals.

Frequency response in the M1 is +/- 0.1 dB from 20 Hz to 20 kHz and -3 dB at 45 kHz, well beyond the limit of audibility.

Frequency response is affected due to feedback not accounting for effects of the output filter.

Feedback is after the output filter, thus already taken into account.

Class D amps use circuits with poor high-frequency resolution resulting in high intermodulation distortion.

Neither of the above are an issue in the M1. Its high-speed control loop includes high-speed instrumentation-grade op-amps with 100 MHz unity gain bandwidth, 3000V/µs slew rate, high-speed complementary comparators and 5-nanosecond Advanced CMOS Logic gates.

Class D amps negatively affect dynamic variations in clarity and focus.

In unbiased double-blind listening tests comparing the M1 with renowned audiophile class AB amps, we proved the M1 provides consistent audiophile sound with unhampered clarity and focus.

High-feedback switch-mode power supplies react dynamically causing power draw variations and encouraging cross-modulation.

With the M1, it’s exactly the opposite situation because a linear supply cannot regulate the output voltage of the output stage. The bus capacitors in the M1’s output stage are replenished 200,000 times per second instead of 100 or 120 times per second as is the case with linear power supplies.

Class D amps suffer from shaped noise floors which vary dynamically according to signal level.

The M1’s noise floor is virtually inaudible.

Class D cannot resolve detail very well. 1-bit DSD pulse width modulation used by SACD operates at over 2.8 MHz which is seven times the rate used by the typical Class D amplifier.

DSD is not pulse width modulation. It is pulse density modulation which is digital, meaning discrete in time. Its time resolution is limited to around 350 nanoseconds. The M1 operates at 0.4 MHz but the time resolution is analog meaning there is no inherent limit on time resolution (though practically speaking it is around 4 nanoseconds). This is 87.5 times better than SACD. Since the output stage runs at seven times lower frequency than DSD one could argue that the actual resolution is that much lower, but even then it’s 12.5 times better than SACD. In any case, the M1’s time resolution is well below noise floor limits and theoretical arguments are a wash when compared to the actual listening test results done in real world setups.

With several designs high DC potential is present on the outputs.

The M1’s outputs idle at ground potential (0V).

A dynamic range compressor is often present to provide soft clipping and this may impair clarity.

The M1 does not use a compressor and its output stage is never allowed to clip.

Class D amplifiers suffer from ‘dead time,’ an ugly form of crossover distortion.

The M1 has no audible effects caused by ‘dead time’ and there is never any overlap to cause electrical problems. Timing is controlled by high-speed Advanced CMOS Logic gates with 5-nanosecond propagation delay and sub-nanosecond skew. The MOSFET gates are well controlled, driven by 9-ampere high-speed MOSFET drivers.

Class D output stages have thermal dissipation issues due to the small size of the power module.

The M1 does not use a module. Operation is discrete with output MOSFETs mounted on a copper clad PCB, then on a heavy aluminum extrusion with heat pipes.

Output stages are fragile. Current limiting with a time and frequency dependent envelope is used to protect them, possibly making sound quality near full output variable and load-dependent.

With its eight 65-ampere MOSFETs (260A peak) the M1’s output stage is not fragile and if there is an over-current condition it simply shuts down.

Stability is conditional and several designs can oscillate when under no load, eventually burning out.

The M1 is stable into any load. Purely capacitive and very capacitive loads will send the M1 into protection mode, not burn out mode but since no speakers are purely capacitive this will never be an issue. Unlike other Class D amps, the M1 is perfectly stable into an open circuit and operates perfectly into a short circuit until the current limit is reached. When it is, the M1 will simply shut down and resume playing a few seconds later.