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Ensuring maximum performance, Core technologies – Krell Industries Evolution One User Manual

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Ensuring Maximum Performance

“My pursuit of excellence in sound reproduction and

my love of great musical performance has led me

to the Evolution One Amplifier, and fuels the ongoing

Evolution design effort at Krell.”

Dan D’Agostino

The Krell Evolution One Monaural Power Amplifier, built upon the foundation of

huge, regulated power supplies and output stages, is designed to drive any

loudspeaker with complete control. The product of breakthrough Krell technolo-

gy, this amplifier provides a sound that is supremely dynamic and musical.

Indeed, it is the sound of the music itself.

Core Technologies

Class A, Balanced, Current Mode Gain
Topologies from Input to Output

Audio signal voltages are converted to currents at the amplifier input, and the

audio signal remains in the current domain throughout the entire amplifier until

the output stages. All signal gain is realized in the current domain using propri-

etary multiple-output current mirrors with extraordinary open loop linearity. The

current mirrors in the final gain stages use 36 pairs of high voltage, high speed

transistors. Originally developed for demanding, high bandwidth video circuits,

these transistors help yield gain stages with superb accuracy and very low dis-

tortion. The signal path is fully complementary and fully balanced from input to

output. The driver and output stages use 28 pairs of 150 Volt, 14 Amp, 50

megahertz power transistors mounted on Krell-designed high efficiency heat

sinks.

All transistors operate in Class A mode. Independent complementary pre-

driver and driver stages for the positive and negative output transistors make

the output stages extremely fast and linear. The output stage develops 450

Watts into an 8 Ohm load, 900 Watts into 4 Ohms, and 1800 Watts into 2

Ohms. This unique circuit is impervious to low-impedance or reactive loads;

the Evolution One amplifier simply drives any loudspeaker with absolute confi-

dence, achieving the very best possible sonic results.

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