EVOLUTION INTEGRATED AMPLIFIER
Evolution products have been developed using 3D solid modelling software and high grade PCB development tools. They are designed to look similar to the new Destiny high-end range, but not to be confused with it. Cosmetically, the Evolution uses a 12mm solid aluminium front panel which is machined to create a visually appealing look and feel.
To achieve 85 Watts power into an 8 Ohms load
and >160 Watts into 4 Ohms, the mains transformer has to be big. The Evolution uses an
over-rated 250VA toroidal transformer, which will provide enough current to
drive the amplifier to almost double its output into 4 Ohms.
To improve the sound quality, no expense has been spared. Separate windings are
used for each of the high current high voltage and low voltage, analogue and
digital circuits. Two sets of rectifiers and a total of 20,000 micro-Farads of
multiple smoothing capacitors are used to separate the left and right circuitry
and improve the dynamic performance. This is a technique used by Creek before
for its up-market products and is now available in the entry-level Evolution. In terms
of value for money, this cannot be over-stated.
Generally, few Hi-Fi companies put so much effort into their product's power
supplies at this price point, but this is an area that, Creek are convinced,
rewards highly for the investment. To allow it to be easily used in different
countries, the Evolution also uses an external voltage selector.
Significantly, the Evolution is the first product made by Creek to use an electronic
volume control. It uses a Burr-Brown PGA2311, stepped resistor attenuator
operated by a microcontroller. This allows the user to adjust the volume
accurately, in 1 dB steps, from 0 to -80dB. An analogue style rotary encoder,
with 40mm solid control knob, is used to alter the volume from the front panel
and display the reverse level in dB on a large blue coloured VFD display i.e. 80
is loudest and 0 is off. To buffer the signals in and out of the pre-amp, high
grade Burr-Brown OPA2134 op-amps are used. Signal switching is performed by
relays, which are driven by signal from a powerful microcontroller, similar to
the Destiny amp.
The Evolution is configured as a high open-loop gain circuit, using a
double differential input and driver stage plus discrete Darlington power output
stage, using high current bi-polar transistors. This is similar to the circuitry
Creek used prior to its more complicated MOS-FET designs. High grade
polypropylene capacitors, bypassed with large value electrolytics, are used to
couple and decouple the signal into the power amp as the Evolution doesn't use a DC
servo correction, like the Classic and Destiny amps.
To keep the amplifier safe, it is monitored by discrete transistor circuitry to
protect against over current demand, short circuits and DC offsets. Relays mute
the input and separate the loudspeaker output in the case of faults.
The Evolution operates conventionally with rotary controls for input selection and
volume control and buttons for Tape selection and power On/off. It has four
inputs plus tape - selection is via the remote handset or the input selection
control. A visual indication of its status is displayed on a large blue Vacuum
Fluorescent Display (VFD). The display brightness can be altered from the Evolution
remote control handset. As with all Creek amplifiers the Evolution has a facility to
fit a Creek phono board and the first input is configured for this purpose. The
phono boards available for this amplifier are the same as those which can be
used in the Classic amplifier.
SPECIFICATION
| Power Output (both channels into 8Ω) | 85 Watts |
| Power Output (one channel into 8Ω) | 90 Watts |
| Power Output (one channel into 4Ω) | 170 Watts |
|
Peak Output Current
into 1Ω
(50 mS)
|
>10 amps RMS |
| Total Harmonic Distortion (20 Hz – 20 kHz) | <0.1% |
| Frequency Response | 5 Hz - 50 kHz -1dB |
| Slew Rate | > 25 V per µS |
| Gain | x 68 |
| Input Sensitivity - One Channel driven/ 8Ω | 415 mV line input |
| Pre-amp output level | Follows input signal level via volume control x 2 |
| Signal to noise ratio ‘A’ weighted | > 96dB |
| Separation (line inputs) | > 60dB @ 1 kHz |
| Mains Power consumption (at idle) | 40 W |
| Mains Power consumption (full power 10% THD) | 340 W |
| Loudspeaker Outputs | One |
| Headphone Output | Yes |
| Weight (net) | 8.6 kgs |
| Size (W x H x D) mm | 430 x 80 x 340 |
| Remote Handset | EVO - Uses NEC codes |