KRELL CD Cipher Power Evolution 2250e Preamplifier Phantom
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Giá bán: 950,000,000 VNĐ

Krell Cipher SACD/CD Player

Featuring an advanced disc drive and coupled to the latest Krell digital and analog output circuitry, the Krell Cipher delivers the ultimate performance from today's highest resolution source material. Every performance enhancement is incorporated to retrieve the most accurate signal from SACD and CD music titles. Isolated mechanically from the underlying chassis, the drive mechanism utilizes composite mounts to minimize vibration induced errors. Special sound dampening material is strategically placed inside the unit to minimize mechanical resonances even further. Krell customized disc drive firmware enhances reading accuracy, drive mechanics, and operational parameter. As an ultimate final step, the separate SACD and CD laser heads are individually calibrated by hand for the precise output levels required for reference quality SACD and CD playback.

All signals are fed into a custom designed Krell anti-jitter module that reduces jitter to a virtually immeasurable level. From there, signals are fed to a 24 bit/192 KHz digital filter and then to a pair of balanced 24-bit/192 kHz digital-to analog converters (DACs). Conventional players use one DAC for both channels and convert the current output of the DACs to voltage, a process that invariably causes signal distortion. Instead, the Cipher uses one DAC per channel and feeds the native balanced current output directly to Krell Current Mode circuitry. Removing the typical current-to-voltage stage found in conventional players eliminates distortions associated with this conversion. Balanced DACs maintain a dual differential balanced signal from the output of the DACs to the output connections. This lowers distortion and improves signal to noise ratio to their maximum levels. Core Krell technologies of discrete, complementary, direct coupled circuitry are employed throughout the surface mount based output stage. Evolution CAST and balanced connections are included for optimal stereo playback. A complete Evolution (source, preamp, amplifier) system, connected in CAST, reduces the number of voltage gain stages to the minimum: one. The resulting noise floor approaches the theoretical limit of technology Outputs are also included for Multichannel SACD playback.

The backbone of all audio components is the power supply which is often minimized in lesser players. The Cipher includes independent power supplies for the drive mechanism, digital, and analog sections to maintain signal isolation between these circuit areas. The Cipher's linear power supply is sourced directly from the designs used in Krell Evolution e Series amplifiers. A custom-wound toroidal power transformer, 10 times larger than those found in typical players, provides tremendous current reserves and assures low-noise analog stage operation. Extensive multi-regulation delivers rock-steady power to all gain stages, ensuring maximum dynamic impact that can get muted in players using switching or digital power supplies.

With the Phantom Preamplifier, musicians appear silhouetted by the air about them, filling the room with a mesmerizing depiction of the recording. Music emanates from an expanse that outlines the recording venue, transporting you to the moment of creation. Coupling advanced technologies and inspired design, the Phantom preamplifier elevates preamplifier performance to an art form.

The Phantom preamplifier is the first Krell preamplifier to include an optional crossover. The crossover functionality offers the ability to use a subwoofer/satellite speaker arrangement and still maintain the highest quality sonic performance. Previous to the Phantom preamplifier, this system configuration would require signals to pass through a subwoofer's lower quality crossover circuitry. The Phantom preamplifier is the centerpiece of a world class audio system where space is at a premium.

Crossover Highlights

Owing to Krell's work in the Modulari Duo Reference loudspeaker, the unique crossover feature is a highly sophisticated option. When the optional board is present, additional crossover menu items become available. Definable parameters include independently assignable crossover frequencies and filter types for the high and low pass sections. Choices include 40Hz, 55Hz, 75Hz, and 100Hz crossover points with 12dB, 24dB, and 48dB Butterworth or 24dB Linkwitz-Riley style filters. The high pass section of the crossover uses the full Phantom preamplifier circuitry for its output stage.

Circuitry Highlights

The Phantom preamplifier is a dual monaural circuit design with the left and right channels afforded their own power supply regulation and individual full chassis sized boards. All signal gain is realized in surface mount topology using proprietary multiple-output current mirrors with nearly 500 times the open loop linearity of other designs 1.5 MHz open loop bandwidth in a zero feedback, balanced, Krell Current Mode design terminating in Krell CAST. A complete Krell system (source, preamp, and amplifier) system, connected using CAST interconnects reduces the number of voltage gain stages to the minimum, one. The resulting noise floor approaches the theoretical limit of technology. Negative feedback is not used anywhere in the preamp, nor is it necessary. Open-loop distortion is typically less than 0.003%. The volume control is realized with a balanced resistor ladder - bandwidth and transient response of the preamp circuitry are virtually unaffected by the volume setting.

Power Supply Highlights

The Phantom audio circuits receive power from a Krell Current Mode analog power supply housed in its own dedicated chassis. The power supply avoids the common integrated circuit topology used in many preamplifiers and instead mimics the design topology of Krell Evolution e Series amplifiers. The circuitry is completely discrete giving it the ability to respond quickly to current demands and also be unaffected by all but the most severe AC voltage power fluctuations. Oversized for a preamplifier, the power supply features a 290 VA transformer and 41,600µF of capacitance. Locating the power supply in its own chassis presents the ideal configuration for isolating stray electrical and magnetic interference from the critical preamplifier signal path. Capable of delivering current and voltage swing for any musical event, the Phantom power supply is gentle on AC requirements when not in use. A new eco-friendly design reduces standby power draw to 2W.

The Phantom preamplifier is offered in diamond-cut silver or a luxurious black finish.

Refined reproduction and overwhelming power define the Evolution 2250e. Boasting technology sourced from award winning larger siblings, the Evolution 2250e provides the immense power and unmatched sound quality that are the hallmarks of all Krell amplifiers. Sharing the same advanced high speed output devices, massive power supplies, and unique Krell Current Mode circuitry; the Evolution 2250e delivers performance that was previously reserved for products costing far more.

Sophisticated and expensive to execute, surface mount circuitry is featured throughout gracing the design with short circuit path lengths, vanishing parasitic capacitance and improved bandwidth. Alone, the Evolution 2250e is ideal for use in stereo music systems. When coupled to the three channel Evolution 3250e, this duo makes ideal amplification for home theater applications.


Blessed with a power supply outfitted with a 2,500 VA power transformer and 136,000 µF of capacitance, the Evolution 2250e is a powerhouse. Power output of 250 W per channel into 8 ohms and 500 W per channel into 4 ohms will drive any loudspeaker to its full dynamic capability. An additional transformer for control and protection circuitry also provides power for a new energy efficient standby mode. Similar to turning off a 150W light that is always on in your house; standby power draw is only 2W. This 99% reduction in electrical usage also reduces heat output substantially. The high-current and high-voltage analog supplies have additional noise filtration circuitry to reduce high-frequency switching noise.


Housed in elegant silver or black brushed anodized Aluminum, the Evolution 2250e is the smallest amplifiers in the Evolution e Series. Featuring a 4U (7" High) profile, the new amplifiers bring prodigious power to applications requiring smaller amplifiers without sacrificing sonic performance. The stylish Aluminum faceplate features the blue power ring when in operating mode and green in low draw standby mode that is shared by all Evolution e Series amplifiers.

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