美国 马克 No.436 单声道后级功放一对 300W功率

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中文介绍：

马克 No.436 单身道后级功放（全新）

英文介绍：
Mark Levinson No.436 monoblock power amplifier

No 436 Power Amplifier

Chassis
The No 434 and No 436 are designed to accommodate standard shelf and rack-mount installations while retaining a strong visual connection with other Mark Levinson amplifiers and source components. The thermal management system uses an exposed internal heatsink. This results in a smooth, elegant appearance and adds a considerable measure of safety while handling the amplifiers. Rear-panel handles also provide an unexpected level of convenience as well as protection for input, output, and control connectors.


Rack-Mounting
Each chassis (three ?rack spaces? tall for the No 434 and four for the No 436) fits precisely into all standard equipment racks. For demanding custom installations, proper ventilation, and hidden cable routing, we provide shelves specifically for these amplifiers.


Control and Communication
As music and cinema systems grow more complex, integrating individual components takes on greater importance. To this end, the No 434 and No 436 feature an entire suite of control and communications capabilities.

• A DC trigger input allows a remote unit (preamplifier or surround sound controller, for example) to switch each amplifier from standby to fully operational status, even after AC power has been temporarily lost.
• A complementary trigger output lets you or an installer ?daisy-chain? multiple amplifiers so they can be controlled from a single low-voltage source.
• The additional Mark Levinson Link ports allow communication and automation features among components in a complete Mark Levinson system.
• As a final sophisticated touch, RS-232 communication ports extend compatibility to any standard external control system.
  

Thermal Management
High current amplifiers must expel potentially damaging heat from the chassis. Traditional techniques include passive external heatsink assemblies where heat-producing power transistors are mounted directly on finned aluminum extrusions that are subsequently convection-cooled by the air rising past the fins. Although successfully used by other Mark Levinson amplifiers, this method poses a challenge when you place powerful amplifiers in smaller enclosed spaces.

To meet this challenge successfully, the No 434 and No 436 amplifiers use a new cross-cut heatsink extrusion that maximizes surface area and allows air flow along either the vertical or horizontal axis.

At lower operating temperatures, convection currents cause air to flow vertically through the chassis. As temperatures rise, whisper fans located at the front and back of the heatsink are activated in a push-pull manner, drawing cool air from behind the faceplate facade, through the horizontal channels of the heatsink extrusion, and exhausting it out the rear of the unit. This air flows through an isolated tunnel to prevent dust from settling on the amplifier circuitry directly and ultimately compromising performance and reliability.

The fans themselves are thermostatically controlled and adjust their speed to the amplifier?s cooling requirements. This ensures that the fans remain inaudible across the widest range of listening conditions.

The combination of cross-cut heatsinks and variable forced air cooling allows easy use even in locations where space and ventilation are limited. Though designed to stand out in a visible installation, these amplifiers also function very gracefully when hidden from view. Wherever you choose to place them, the No 434 and No 436 amplifiers are all-Levinson and thus simply the best you can buy.


Protection
The No 434 and No 436 offer a complete protection system to extend their useful life and guard against damage to adjacent system components.

? Servos correct for up to ± 1V of direct current (DC) offset from a source component. This prevents potentially harmful DC from reaching the loudspeakers.
? Thermal sensors monitor the operating temperature of the amplifier, switching it off before it can over-heat.
? Excessive current drawn from the amplifier may indicate a component failure or shorted loudspeaker connection. In either case, the amplifier will switch itself off to prevent unnecessary damage.
? Expensive power supply components are protected from turn-on transients and power line spikes as is standard on all Mark Levinson equipment.


Audio circuitry
The audio circuits, from power supply to output stage, are designed and voiced to allow seamless use with other Mark Levinson amplifiers. You can build a multi-channel system with full confidence that the No 434 and No 436 will integrate fully with your current and future selection of Mark Levinson components.




Power Supply
A monaural power amplifier has one major advantage over stereo or multi-channel designs. You can rest absolutely sure that its dedicated power supply will never be compromised by simultaneous demands from more than one signal. But separation alone does not ensure amplification circuits of sufficiently clean and stable power. Oversized transformers, filter capacitors and conductors make important contributions to performance, while bypass capacitors and voltage regulators further purify the power digested by the audio circuits. Perfectly clean, instantly available power allows the circuitry to perform properly without introducing noise and distortion into the audio signal.
An installation-friendly detachable power cord simply increases flexibility. These amplifiers will go where you want them to. But they?ll do only one thing ? provide extraordinary Mark Levinson sound quality wherever you put them.


Voltage Gain Stage
I homage to past Mark Levinson successes, the sensitive voltage gain stages in both the No 434 and No 436 are powered from DC regulator amplifiers. The voltage gain stages are also fully balanced, with their sonic performance further optimized with Arlon® 25N cyanate ester circuit board material.

We use Arlon rather than less costly circuit board materials for a simple reason: It is better. In particular, Arlon?s stable dielectric constant permits much more precise transmission of the low-level analog AC signals processed by the amplifier?s voltage gain stage. The result is higher resolution, better bass definition, greater focus, and more precise control over dynamics.


Current Gain Stage
Output devices, selected after extensive technical and sonic evaluations, are the same as those used in other Mark Levinson amplifiers. This helps maintain the signature ?Levinson sound? that has distinguished our products for many years. These carefully-chosen individual components also allow us to optimize PC board layout and improve power distribution throughout the output (current gain) stage.

In addition, we use ?adaptive biasing? to manage the output stage?s power source for best performance without excessive heat or wasted energy. First developed for the No.33 Reference Monaural Amplifier, adaptive bias technology has proven its worth in thousands of Mark Levinson amplifier installations as it combines the sonic benefits of low switching distortion common to class A designs with the efficiency of typical A/B amplifiers.

The result is a sonic character that suggests unlimited reserves of power while retaining the finesse associated with the best sounding low-power amplifiers.


Sonic Performance
The single most important feature of these new amplifiers is the one that alone justifies their purchase: Performance. Initially intended to simply match the sonic quality of previous designs, the No 434 and No 436 actually eclipse that goal.

Since the No 434 and No 436 share circuit topologies and materials with previous designs, their sonic character is similar. The benefit, obviously, is that owners of a 300 Series amplifier, for example, may add one or several channels to their system without sonic compromise. In fact, the dedicated single chassis and careful parts selection allowed our design team to further refine performance.

The mono amplifiers share some of the sonic attributes of the No 33 and No 33H, including higher resolution and dynamics, and a greater sense of effortlessness. They are as well suited to a top quality two-channel music system as they are to a world-class multi-channel music and theater system.