Description

To maintain a family resemblance with the lower powered amplifier, the EVOLUTION 100A is housed in a similar slim case with engraved front panel and solid metal control knobs as the EVOLUTION 50A.
It is available with either a Black or Silver brushed aluminium front
panel and uses the same ingenious soft push button design as the EVOLUTION 50 series, offering excellent tactile feel and backlit optical indication of functions, for optimum user-friendliness.

The front panel features a large OLED (Organic Light Emitting Diode)
display. The white on black display provides higher clarity and
resolution than a normal display and has a wide range of customised
graphic symbols. Display brightness levels can be changed or turned-off,
if not required, via the menu system.

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; The EVOLUTION 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.

The Pre-amp circuit provides high levels of flexibility and control,
via unbalanced or balanced inputs. It has multiple input options,
switched either electronically or by gold contact relays. It also has a
State-of-the-Art electronic Volume, Balance and Tone controls. Volume
control and op-amp circuit outputs are all buffered with constant
current sources, to provide improved load tolerance and stable
distortion characteristics.

Correct grounding is difficult, if not impossible, in an un-balanced
amplifier, so Creek has provided the consumer with a balanced line input
for both the pre-amp and power amp input. The matching EVOLUTION 50CD also has a balanced output capability. In addition, the optional RUBY DAC module also benefits from having a dedicated balanced audio connection to the EVOLUTION 100A’s pre-amp, via its flat foil cable, to avoid potential ground loops inside the amplifier.

It is a modern listening trend for headphones to now be fed from low
voltage sources, such as smart-phones and portable music storage
devices. This required the development of low impedance headphones, to
draw the required current to make them loud enough to satisfy the
consumer. This trend has also necessitated a re-think of circuitry used
in modern Hi-Fi amplifiers, to drive such low impedance headphones,
together with the traditional medium to high impedance versions also.

Creek Audio has taken the unusual step of driving the headphone output socket of their EVOLUTION
amplifiers from a dedicated low impedance source. Instead of the
headphone output being sourced from the power amplifier, the headphone
output is derived from a dedicated amplifier, with only a few Ohms in
series for protection against short circuits. This dedicated HP amp is
now located on the pre-amplifier circuit board.

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Excellent overall measured and sonic performance has been achieved
with this analogue integrated amp, but when used together with the
matching EVOLUTION 50CD,
the analogue pre-amp can be bypassed completely, to allow the volume to
be controlled in the digital domain. Connecting the output directly to
the “Power amp AV direct” inputs elevates the performance to an even
higher level, by reducing noise and distortion associated with active
pre-amplification.

Creek Audio no longer makes a separate FM Tuner, but die-hard
analogue tuner fans can continue to enjoy this valuable format by using
the top-quality AMBIT plug-in tuner module, which augments the EVOLUTION 50A and 100A’s capabilities. The AMBIT or RUBY modules are mounted on the back panel ‘Smart-Slot’, replacing Line Input 5.   When the AMBIT
is fitted, it automatically turns the amp into a Receiver, configurable
for use in any region of the world. The OLED display shows all the
tuner’s functions and it’s controlled by the left hand buttons and
control knobs, as well as remote control.

Coming soon, the RUBY plug-in DAC module also
replaces Line Input 5. It features 2 x 24/192 SPDIF, 2 x TOSLINK digital
inputs, 24/96 USB, Bluetooth and FM radio inputs, in addition to the
existing 4 analogue line inputs.

For vinyl fans, the EVOLUTION 100A can also be
configured for Vinyl Disc input, using Line input 1. A SEQUEL 2 (40, 48
or 54) module can be plugged into a dedicated connector on the pre-amp
PCB. It doesn’t restrict the use of either the AMBIT or RUBY modules. Sequel 2 comes in three versions – 40dB MM, 48dB MC and 54dB MC.

To simplify the many options a stylish system remote handset controls all the functions of the EVOLUTION 50 and 100 series. An optional IR extender to enable the products to be hidden away, but still operable via remote control.

The EVOLUTION 100A is the most sophisticated and
reasonably priced amplifier Creek has ever made. It provides stunning
audio performance and is capable of out-performing other makes of
amplifiers costing many times the price.