evolutioneseries_name (1K)
"It is hands down the best amplifier I've ever heard and the new benchmark for which all future cost no-object amplifiers will be judged." Andrew Robison in Evolution 402e review on

Krell amplifiers are best known for their ability to drive any loudspeaker to sound its best, without regard to impedance, efficiency, or driver style. It is linearity, an amplifier's ability to output an exact duplicate of the input signal, which is the ultimate measure of that amplifiers worth. Krell designs toward the common goal of linearity; through the rigorous application of Krell design principles that focus our efforts on four major performance factors: distortion, bandwidth, output impedance and current capability. The Evolution e Series excels in each of these areas, delivering supreme accuracy from whisper level to astounding, awe inspiring amounts of power with grace and elegance.

400e (45K) We are excited to announce the initial shipments of the Evolution 402e, Evolution 403e, Evolution 600e, and Evolution 900e have begun. The Evolution 302e and Evolution 400e are shipping in July.

Building on the unique Active Cascode Topology foundation of the Evolution Series, the e Series amplifiers feature more precisely balanced current sharing among the seven sets of Active Cascode Quartets that make up the output stage. This greater precision

elevates an already impressive performance envelope and provides greater amplifier reliability. Audible at all volume levels, this improvement is independent of load current. Although negative feedback in the Evolution amplifiers was already extremely low, a mere 14 dB---several orders of magnitude lower than other manufacturers' power amplifiers, modifications to the feedback circuitry allow for more ideal operation completely independent of the signal level. The results are greatly enhanced inner detail and micro-dynamics with smoother high frequency response.

"I've heard a lot of great amplifiers over the years and have even reviewed a few in the months leading up to the 402e's arrival in my home and the 402e not only bested each and every one of them but it did so at a fraction of the cost." Andrew Robison in Evolution 402e review on

An intense upgrade to the power supply includes a number of improvements. There is now a separate transformer for the digital power supplies. Not only does this facilitate greatly reduced power consumption in standby, but it provides still better isolation between the digital and analog power supplies. The high-current and high-voltage analog supplies have additional noise filtration circuitry to reduce high-frequency switching noise from the rectifiers. The high-current power supplies also have more reservoir capacitance than before (anywhere from 10-50% more, depending upon the model). Finally, the power supply circuit board has been redesigned for better isolation between the incoming AC power and the DC power supplies.

600e (36K)
A new green standby mode reduces standby power draw dramatically. Standby power draw for all Evolution e Series amplifiers has been reduced to 2W. As an example, the Evolution 402 power draw drops from 260W to 2W in the Evolution 402e - a reduction of 99% in energy draw and a huge drop in heat output. The power indicator ring now glows green to indicate the new energy efficient mode.

"I walked away from my listening session simply amazed at how Krell was able to turn an already solid amplifier in the 402 into an amp that bordered on otherworldly
with the 402e. No matter what the genre or volume level, the 402e never ceased to amaze."
Andrew Robison in Evolution 402e review on