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Features
The Evolution 302e is a powerhouse stereo amplifier in a compact chassis.
Packing advanced Evolution circuit technology and prodigious power output, the
Evolution 302e delivers superior performance in smaller scale applications. This
power is coupled to a modest 2 watt power draw when in standby mode. Perfectly
matched with an Evolution 222 preamplifier for stereo application, the Evolution
302e also shines as the Left and Right amplifier when coupled to an S-1200
Surround Preamplifier/Processor in a home theater system.
Power Supply
The Evolution 302e is equipped with a
massive with a 3000 VA transformer. This power source is the backbone for the
output of the Evolution 302e. With this foundation, the Evolution 302e delivers
300 watts into 8 Ohms, 600 watts into 4 Ohms, and 1,200 watts into 2 Ohms with
all both channels driven simultaneously. The FTC mandates that power ratings are
quoted using a 1000 Hz sine wave into a fixed 8 Ohm resistor with final power
specification stated at 1% distortion. Krell engineering considers this
specification too lenient and not indicative of what an amplifier is required to
provide. Krell designs to a much stricter standard. Our power tests use a
20-20,000Hz signal into 8, 4, and 2 Ohm loads. Our power tests use a 20-20,000Hz
signal into 8, 4, and 2 Ohm loads with our final specifications stated for .1%
distortion.
Internal high-current line conditioning circuitry effectively blocks RF noise
entering via the AC line and compensates for any asymmetry or DC offset in the
power waveforms. The amplifiers' low level and gain stages are powered via multi
regulated rails that provide total immunity from supply fluctuations and assure
noise-free circuit operation. Primary rail voltages are quasi-regulated,
enabling an "on-demand" supply of power that is highly responsive to dynamic
load.
Circuitry Highlights
Krell's new Active Cascode Topology™
is a significant departure from traditional amplifier circuits where the
positive and negative rail voltages are each applied entirely across a single
row of transistors. High voltage swing and gain requirements dictate that the
transistors be "pushed" into non-linear operating regions and, in some cases,
dangerously close to breakdown. Krell topology divides the full voltage swing
across multiple rows of transistors, and all devices are active-biased (i.e.,
they all carry the audio signal). Because individual transistors in the cascode
array "see" only a proportional fraction of the rail voltage, they operate in a
region that provides optimum linearity, gain, and safety. And because the
devices are not being pushed to their limits, the amplifier runs cooler and more
reliably. The improved linearity and stability greatly reduces the need for
negative feedback, which is known to cause sonic degradation. Krell Evolution
power Amplifiers use only 14 dB of feedback throughout the topology-a small
fraction of the amount implemented in typical designs.
Krell Active Cascode Topology™ offers several performance advantages. It
breaks through bandwidth limitations of conventional designs and delivers very
high current. The usable bandwidth of an Evolution 302e is 300 MHz; triple the
bandwidth of a typical high performance amplifier. The result is near perfect
performance in the audible range with no phase anomalies typical of lower
bandwidth designs. Because the "work" is spread across multiple devices, the
amplifier is more load tolerant. Open-loop output impedance is extremely
low-about one hundred times lower than with most power amplifiers-ensuring
exceptional speaker control. All of these performance gains are achieved while
maintaining a high rail voltage, which provides a beneficial "flywheel" effect-a
de facto regulation that enables the amplifier to better deal with sudden
changes in power requirement, such as those caused by large signal
transients.
Evolution amplifiers feature Krell CAST technology. CAST is a unique circuit
and connection breakthrough that eliminates distortions inherent in voltage
based amplification. A complete Evolution (source, preamplifier, and amplifier)
system, connected with CAST interconnects reduces the number of voltage gain
stages to the minimum, one. The resulting noise floor is approaching the
theoretical limit of technology. Emanating from a completely black background,
music explodes from absolute silence moving the listener closer to the goal of
recreating the live musical event in the listening room.
제품 Specfications
Frequency response
20 Hz to 20 kHz +0, -0.10 dB
<0.5 Hz to 180
kHz +0, -3 dB
Signal-to-noise ratio
>107 dB,
wideband, unweighted, referred to full power output
>117 dB,
"A"-weighted
Gain
25.5 dB
Total harmonic distortion
<0.02% at 1 kHz, at 300 W, 8 Ω
<0.15% at 20
kHz, at 300 W, 8 Ω
Input impedance
Single-ended: 100 kΩ
Balanced: 200 kΩ
CAST: 75 Ω
Input sensitivity
Single-ended or balanced: 2.60 V RMS
CAST: 2.60 mA RMS
Output power
300 W RMS at 8 Ω
600 W RMS at 4 Ω
1200 W RMS at 2 Ω
Output voltage
139 V
peak-to-peak
49 V RMS
Output current
35 A peak
Slew rate
120 V/μs
Output Impedance
<0.040
Ohms at 20 Hz
Damping Factor (referred to 8 ohms)
>200 at 20 Hz, referred to 8 Ω
>150, 20 Hz to 20 kHz, referred to 8 Ω
Power consumption
Stand-by: 2 W
High Current Stand-by: 150 W
Idle: 320 W
Maximum: 3400 W
Heat Output
Stand-by: 7 BTU/hr.
High Current Stand-by: 510 BTU/hr.
Idle: 1100 BTU/hr.
Maximum: 5500 BTU/hr.
Inputs
2 single-ended via RCA connector
2 balanced via XLR connector
2 CAST via 4-pin bayonet connector
Outputs
2 pairs Krell binding posts
Dimensions
17.3 in. W x 9.8 in. H x 20.7 in. D
438 mm W x 248 mm H x 525 mm D
Weight
Shipped: 138 lb., 62.4 kg
Unit Only: 120 lb., 54.3 kg