Fully Balanced Discrete Volume Control

The volume control is realized with a 16-bit balanced resistor ladder, which uses low-resistance, high-linearity solid-state switches and discrete precision resistors. Control signals for the switches are optically coupled for low noise and maximum signal integrity. The bandwidth and transient response of the preamplifier circuitry are virtually unaffected by the volume setting. As a result high frequencies sound especially smooth and extended, and music seems to emerge from “jet black” silence. The analog and digital signal paths are not interconnected. Where neces- sary, digital control signals are optically coupled to analog circuits.

The Evolution Two has two buffered tape outputs: one linked to the main signal- selection bus, and another with its own independent signal-selection bus. This allows the option of listening to one source while recording another, or the option of connecting two tape decks having different input signals. Both tape outputs have single-ended and voltage outputs. Either the fourth single-ended input or the third balanced input can be user-configured as a tape monitor input, allowing the opportunity to use home or professional recording equipment.

Separate Power Supply

Housed in a separate chassis, the power supply makes use of extensive electrical and magnetic shielding to keep radiated interference out of critical preamplifier cir- cuits. Internal line conditioning circuitry filters RF noise on the AC power, and compensates for asymmetric power waveforms and DC on the mains.

Power for the analog stages comes from a large 170 VA toroidal transformer. This transformer drives four 8-amp bridge rectifiers and 39,600 microfarads of filter capacitance. Each monaural preamplifier has as much power supply capability as many stereo power amplifiers.

The main regulators for the analog stages are scaled-down versions of those used to power the output stages of the Evolution One amplifier. Operating in current mode, with fully complementary gain stages and output drivers, wide bandwidth, low output impedance, and high current capability, the main regulators easily exceed the requirements of the analog stages. The driver and output stages in the main analog regulators use five pairs of 150 Volt, 8 Amp, 40 megahertz power transistors.

A dedicated 90 VA toroidal transformer with three independent secondary wind- ings powers the preamplifier's digital control circuitry. The regulators for the con-

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Krell Industries EVOLUTION TWO MONAURAL PREAMPLIFIER manual Fully Balanced Discrete Volume Control, Separate Power Supply
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EVOLUTION TWO MONAURAL PREAMPLIFIER specifications

Krell Industries has long been a name synonymous with high-fidelity audio equipment, and their EVOLUTION TWO MONAURAL PREAMPLIFIER is a testament to this legacy. This premium preamp is designed to cater to audiophiles, delivering unparalleled sound quality and meticulous attention to detail.

At the heart of the EVOLUTION TWO lies Krell's commitment to superior audio performance. The preamplifier employs a fully balanced, differential signal path that minimizes noise and distortion, ensuring that the audio output is pure and true to the source. This architecture not only enhances sound quality but also integrates seamlessly with other high-end audio components in any setup.

One of the standout features of the EVOLUTION TWO is its advanced power supply design. Krell employs a toroidal transformer coupled with high-energy storage capacitors to provide stable, clean power. This allows for improved dynamics and transient response, helping to reproduce the complex nuances of music in a way that engages the listener. The preamplifier's power supply is designed to operate with extreme efficiency, ensuring consistent performance even during the most demanding listening sessions.

Additionally, the EVOLUTION TWO comes equipped with Krell's proprietary CAST (Current Audio Signal Transmission) technology. This innovative feature allows for a direct, impedance-matched connection between components, significantly reducing signal degradation over long cable runs. Audiophiles will appreciate the clarity and fidelity produced by CAST, revealing subtle textures and details in their favorite recordings.

The preamplifier also includes a range of inputs and outputs, catering to various audio sources and systems. Users can connect multiple devices, including digital sources, with ease, thanks to the EVOLUTION TWO's advanced input switching capabilities. The unit supports balanced XLR connections as well as unbalanced RCA outputs, providing flexibility for users with different equipment configurations.

Moreover, the EVOLUTION TWO MONAURAL PREAMPLIFIER boasts a stunning aesthetic, showcasing Krell's hallmark design philosophy. With its sleek chassis and elegant finish, the preamp not only sounds good but looks great in any audio setup.

In summary, the Krell Industries EVOLUTION TWO MONAURAL PREAMPLIFIER is a high-performance audio component that encapsulates cutting-edge technology and exceptional craftsmanship. With its balanced signal path, innovative power supply design, CAST technology, and versatile connectivity options, it is a remarkable addition to any serious audiophile's system, promising a listening experience that truly transcends the ordinary.
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