Description
In addition to greatly increased performance, thanks to ingenious new circuit design, the EVOLUTION 100A has been equipped with 2 sets of high quality loudspeaker binding posts, with local and remote switching for A & B outputs. Optional extras include the ability to plug the Sequel mk2 Phono pre-amp inside and add the AMBIT FM/AM radio or RUBY DAC/Bluetooth/FM radio module to the expansion slot on the rear panel.
At the heart of any high-end amplifier there must be a good power supply; TheEVOLUTION 100A uses a massive 360 Watt, low profile, toroidal mains transformer, with multiple windings for high and low voltages and current, to separate the power amp, pre-amp and digital circuitry. Creek’s long-standing design policy of paralleling several small capacitors in the power supply creates an ultra-high specification capacitor, with low inductance and ultra low impedance. This significantly improves filtering and helps produce a very powerful and accurate sound from such a relatively small amplifier.
After testing several methods of building a high performance and high efficiency power amplifier, suitable for this new model, David Gamble – Creek Audio’s Senior Engineer – created a unique Class G circuit especially for the EVOLUTION 100A. David chose to use four Sanken STD03 complimentary power Darlington transistors per channel, as used in the EVOLUTION 50A, which feature built-in thermal compensation. Compared to the EVOLUTION 50A, he improved the performance of the voltage gain circuitry, which, in combination with the output stage, now achieves extremely high open-loop gain and exceptionally low distortion, without sacrificing stability. The result is an exceptional power amplifier circuit with very low output impedance and high output current capability. This combination provides exceptional speed and control suitable for driving most loudspeakers.
To increase the power output of the smaller EVOLUTION 50A, yet still retain the same case size, David Gamble developed a cunning Class G circuit which runs normally at a lower voltage for power levels up to 25 Watts into 8 Ohms. When required to produce more than 25 Watts, the amp automatically swings to a higher secondary voltage, to increase the output power capability to over 100 Watts into 8 Ohms.
Statistically, average audio signals are mostly below half the maximum voltage swing available, which incidentally is only one quarter of the power. As the dissipation of lossy ‘idle current’ in a Class A/B amp (in the form of heat) is much lower for a 25 Watt amp than the potential 100 Watts in the EVOLUTION 100A, this solution dramatically improves the amplifier’s thermal efficiency and helps to keep it slim and attractive.
Optional extras include the ability to plug the Sequel mk2 Phono pre-amp inside and add the AMBIT FM/AM radio or RUBY DAC/Bluetooth/FM radio module to the expansion slot on the rear panel.
