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Power Supplies 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 windings When the Evolution Two is placed in stand-by, all the analog circuitry continues to operate at the same bias current; however, the main analog supply voltages decrease by 30 percent. The result is a corresponding 30 percent reduction in power consumption and heat without the need to wait for the electronics to "warm up" before listening. Zero Feedback Balanced Current Mode Design All signal gain is realized in the current domain using proprietary multiple-output
current mirrors with nearly 500 times the open loop linearity of other designs.
Negative feedback is not used anywhere in the Evolution Two preamplifier, nor is it
necessary. Open-loop distortion is typically less than 0.005% (50 parts per million),
and the open loop bandwidth extends to two megahertz. The result is an
extraordinarily wide and deep image, with an open, effortless sound.
The signal switching relays are hermetically sealed and use gold-plated bifurcated
contacts for maximum signal integrity. Where needed multiple relays are connected
in a "T" configuration to virtually eliminate crosstalk from unselected inputs.
The volume setting can be adjusted and displayed either numerically, from 0 to
151, or in dB, from - inf to +12.0 dB. 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. Advanced Microprocessor Control and Custom Software A built-in digital network allows multiple preamplifiers to be linked together, blending the convenience of a single-chassis stereo preamplifier with the sonic performance obtainable only from individual monaural preamplifiers. Six or more preamplifier channels can be "daisy-chained" together and controlled simultaneously for multi-zone or home theater applications. The digital link allows the user settings in one preamplifier channel to be conveniently "cloned" to other linked preamplifier channels. Similarly, upgraded software in one preamplifier channel can be installed in other preamplifier channels using the digital link. In the event that the DC level at any of the preamplifier channel outputs exceeds a nominal level, sophisticated protection circuitry safely mutes the outputs, traces the source of the excess DC, and displays a diagnostic message on the main display. On power-up, the microprocessor verifies that all the circuit boards in the preamplifier channel are properly connected and are compatible with the version of software installed.
The Absolute Sound"I find it truly hard to believe you can find anything that provides better performance" |
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