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Isis
Introducing the Rega ISIS flagship CD player
We are very proud to
introduce the 7th generation of Rega CD player .
A product manufactured to
the highest achievable quality inside and out, Rega's own unique CD
technology, genuine black chrome lid and front facia, a custom solid
anodised aluminium case weighing in at a notable 19kg ! We hope you
enjoy this very special CD player; Rega has spent a very long time
creating it, drawing on their many years of experience in specialist Hi-Fi
manufacturing.
Technology behind the
design of the Isis
One important design goal
was to take the current output, with no internal amplification within
the D to A converter, and convert this to an analogue voltage, using
discrete class A operational amplifiers and filters. This circuit
can then be optimized for sonic performance. (With most CD
players the use of standard operational integrated circuits locks you
into the sound of those particular integrated circuits, thus narrowing
the scope for improvement).
The class A current to
voltage conversion amplifier evolved out of the development of the first
stage of the Rega IOS MC amplifier.
It shares identical
demands of low noise, high drive capability and gain bandwidth
required of the voltage to current amplifier.
Careful choice has been
made for every component in the digital and the analogue signal path to
ensure the integrity of the signal.
The analogue and digital sections are bonded together using a
substantial ground plane. It was found during the development of the
player that
adoption of RF ground plane techniques aided the sonic quality and
therefore were included in the final design.
Careful design of the PCB's
ensures isolation of not just the digital and analogue sections, but
also the motor, display and user interface processor.
All sonically critical
electrolytic capacitors have been by-passed with polypropylene or
polyester film capacitors.
In addition to this, large value electrolytic capacitors have also been
by-passed with audio grade electrolytic capacitors.
Power supply impedances in the digital to analogue converter are kept
very low by the use of solid polymer capacitors.
All power supplies utilise
custom Rega K-Power smoothing capacitors, along with fast diodes
which have been used throughout in power supply rectification.
The Isis uses enhanced
and optimised control code for the control of the CD processor and
user display.This speeds up the initialisation process by means of a
tighter control interface between the user micro and CD processor.
Analogue section
The analogue section employs two Burr Brown PCM1794 digital to
analogue converters, running in a parallel dual mono mode, driving a
high performance discrete class A current to voltage amplifier.
This combination generates an
exceptionally wide dynamic range, low distortion, and linear
signal. This drives an enhanced discrete class A output amplifier. The
circuit is fully balanced from the digital to analogue converters to the
balanced analogue XLR outputs. The analogue stage has its own dedicated
50VA mains transformer which ensures galvanic isolation between the
digital and analogue sections of the player. You will find 10
separate power supply regulators are used in the analogue circuit
and each individual amplifier stage has its own dedicated low noise
voltage reference.
Digital section
The digital section is blue printed and selected, with major
improvements to the mechanism, optical amplifier, DSP core, PLL, master
clock & motor power supplies. Another 10 separate power supply
regulators are used in the digital circuit. The motor, user
interface processor & display also have their own power supply. The
digital stage also has its own 50VA transformer again ensuring galvanic
isolation. The mechanism is graded and matched to the servo circuits,
to ensure the servo and optical amplifiers are working at their optimum
point, improving error correction and playability. The headroom of the
optical amplifier has been improved by 10% by increasing the voltage in
the power supply.
Digital
This revolutionary player has been five years in design. Rega, together
with its design partners have pioneered a highly advanced servo
controller that uses the latest signal processing techniques to ensure
that the raw data that is recovered from the disc is of the very highest
quality. Because our fully digital servo can use highly advanced
algorithms the laser spot is kept in the optimum position for data
recovery in terms of focus, size and tracking.
Extra Error Correction
Previous chip-sets always made compromises on error correction. Formerly
it was possible to have good jog resistance or better musical
performance.
The Rega chip-set allows optimum musical performance and optimised jog
/vibration resistance.
Super-stable phase lock loop
The entire IC is clocked via a very special PLL of our own design. This
allows better CD data recovery as well as a big improvement in the
quality of the data delivered to the DAC.
Low noise digital design
In the design of our CPU IC we went to great lengths to ensure that the
data and address bus noise was kept to an absolute minimum. This ensures
the ground and signal connections to the DAC are as 'clean' as is
possible.
USB Input
Allowing direct connection to a laptop or PC via a USB A-B lead to
stream internet radio Mp3 or WMA files directly from your computer via
the high quality ISIS internal DAC.
The USB input uses an isolated double-clocked USB interface, which
permits the digital to analogue stage to be used with a computer USB
interface and it's own regulated power supply.
The USB benefits once again from galvanic isolation from the main
circuitry of the ISIS player which eliminates the flow of earth currents
between the CD and host computer, and eliminate computer power supply
noise.
Disc Analysis
The ISIS will analyze each disc on an individual basis. During the
initializing period (rather like the engine management system on a
modern car which optimizes the engine settings to temperature, fuel
quality etc.) the ISIS will adjust itself to each disc in order to give
optimal trouble free reading. For this reason the ISIS will often play
discs with marks or scratches that other players cannot read.
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