User`s manual

Thank you for purchasing this Azur 840A V2 Class XD Integrated
Amplifier. We hope that you will enjoy many years of listening pleasure
from it.
The 840A V2 features our unique proprietary amplifier topology; Class
XD™ , designed to eliminate crossover distortion at low signal levels.
By actively displacing the crossover point this technology creates a
region of pure Class-A operation where the crossover zone would
otherwise be before moving into an enhanced form of Class B at higher
levels. It should not be confused with Class AB, which gives a small area
of Class A, but at the cost of higher distortion as soon as the signal level
moves outside the AB area. Class XD circuitry not only removes
crossover distortion from the zero-crossing point but also reduces
distortion in the other parts of the amplifier's output range.
This V2 version of the 840A features our latest development of Class XD
with many tweaks and enhancements from our on-going research
resulting in our best sounding implementation to date.
A white paper on this patent pending technology is available on our
website: www.cambridge-audio.com
Please note that because of the Class XD technology the 840A V2 runs
slightly warmer than a conventional Class B/AB amplifier and the
ventilation slots on the top of the unit must not be obstructed.
Other features include the use of precision resistor ladders switched by
gold plated relay contacts for the volume and balance controls rather
than the more common solid-state or volume potentiometer schemes.
Volume is controllable in 1 dB steps over most of the range, giving very
fine control, an accurate logarithmic law and superbly accurate channel
balance. Input switching is also by high quality gold contact relays.
The 840A V2 features separate transformer secondaries for left and
right channels, twin rectifiers and separate PSU's for dual mono
operation of the left and right power amplifiers. A separate transformer
supplies the preamp making the 840A V2 effectively a Pre and Power
amp combination in one box.
Input 1 features a balanced input using XLRs giving optimal
performance with equipment such as the matching 840C Upsampling
CD player which features balanced outputs.
The casework combines massive structural rigidity with careful damping
and control of acoustic resonance. An Azur Navigator remote control is
also provided, giving full remote control of your amplifier in an attractive
and easy to use handset.
We have also included support for multi-room use. By plugging in one or
two external Cambridge Audio Incognito keypads and a power supply
unit your amplifier can become the hub of a simple multi-room system.
In addition, Control Bus Input/Output, IR Emitter Input and RS232
control are featured making it easy to integrate the 840A V2 into a
Custom Installation system if desired.
Your amplifier can only be as good as the system it is connected to.
Please do not compromise on your source equipment, speakers or
cabling. Naturally we particularly recommend models from the
Cambridge Audio Azur range. These have been designed to the same
exacting standards as this amplifier. Your dealer can also supply
excellent quality Cambridge Audio interconnects to ensure your system
realises its full potential.
Thank you for taking the time to read this manual; we do recommend
you keep it for future reference.
Matthew Bramble,
Cambridge Audio Technical Director
and the Amplifier design team
2
Contents Introduction
Introduction .................................................................................................2
Limited warranty..........................................................................................3
Safety precautions ......................................................................................3
Important safety instructions .....................................................................4
Rear panel connections..............................................................................5
Front panel controls ...................................................................................6
Remote control............................................................................................7
iPod compatibility........................................................................................7
Connections ................................................................................................8
Operating instructions ..............................................................................10
Amplifier setup..........................................................................................10
Multi-Room connections ..........................................................................12
Custom installation use............................................................................13
CAP5 protection system ...........................................................................14
Troubleshooting.........................................................................................15
Technical Specifications...........................................................................15