Chord Indigo Digital Preamplifier User manual

Indigo Digital Preamplifier

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CONTENTS
PRODUCT DESCRIPTION..................................................................................................................4
INVENTORY..........................................................................................................................................4
WHEN SETTING UP ............................................................................................................................5
SAFETY WARNINGS...........................................................................................................................6
AC POWER CONNECTION................................................................................................................7
AC CONNECTOR .................................................................................................................................7
POWERING UP ......................................................................................................................................7
POWERING DOWN ................................................................................................................................7
CONNECTING YOUR EQUIPMENT ................................................................................................8
DIGITAL INPUT CONNECTIONS.....................................................................................................9
USB......................................................................................................................................................9
DUAL COAX......................................................................................................................................9
AES1 &AES2......................................................................................................................................9
OPT.1 &OPT.2...................................................................................................................................9
ANALOGUE INPUT CONNECTIONS.............................................................................................10
OUTPUT CONNECTIONS.................................................................................................................10
OUTPUT CONNECTIONS.................................................................................................................11
WORD CLOCK OUTPUT .....................................................................................................................11
HEADPHONES....................................................................................................................................12
USB HUB ..............................................................................................................................................12
IPOD DOCK.........................................................................................................................................12
WIRELESS RADIO CONNECTIONS ..............................................................................................13
BLUETOOTH RECEIVER.....................................................................................................................13
CHORD DIGITAL RF LINK.................................................................................................................13
EVERYDAY USE OF YOUR INDIGO .............................................................................................14
TURNING ON YOUR INDIGO................................................................................................................14
SELECT THE INPUT SOURCE...............................................................................................................14
BLUETOOTH INPUT PAIRING PROCEDURE........................................................................................15
FREQUENCY INDICATION ..................................................................................................................15
BUFFER SETTING ...............................................................................................................................15
PHASE SETTING .................................................................................................................................15
ADJUSTING THE VOLUME ..................................................................................................................15
SPECIAL FUNCTIONS ......................................................................................................................16
USING THE REMOTE CONTROL..................................................................................................17
SELECTINGTHE INPUT SOURCE ...........................................................................................................18
ADJUSTING THEVOLUME ....................................................................................................................18
MUTE..................................................................................................................................................18
TO UN-MUTE........................................................................................................................................18
CONTROLLING THE IPOD ..................................................................................................................18
MAINTENANCE .................................................................................................................................19
ADJUSTING THE SETTINGS.................................................................................................................19
CLEANING ..........................................................................................................................................19
CHANGING THE BATTERIES IN THE REMOTE CONTROL ...................................................................19
SERVICING .........................................................................................................................................19
FREQUENTLY ASKED QUESTIONS .............................................................................................19
PRODUCT SPECIFICATION............................................................................................................20

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Indigo Digital Preamplifier
Thank you for buying a Chord Electronics product.
Before you start to enjoy your preamplifier, please take a couple of minutes to read how to connect your audio
equipment and how to maximise your listening experience.
Product Description
The Indigo is the very latest in our digital product development specifically designed to be the universal control
centre for both digital and analogue sources. It takes our most advanced technology and combines it into one
convenient full sized product. The Indigo is fully featured including a revolutionary digital iPod dock with wireless
radio link option. Using the Chord modified iPod (option) a true digital output can be obtained to feed directly into
our DAC circuitry. We have chosen to modify the iPod to gain this direct digital feed so that unlike other USB
based products it does not interfere with the control and operation of the iPod. If uncompressed music files are
used this can at last turn the iPod into a true high end music source. Using the supplied adapter digital music can
also be streamed wirelessly via digital radio link from a modified iPod anywhere in a room allowing for more
useful and convenient control from your armchair. For unmodified iProducts we are providing a standard high
quality A2DP radio dongle and this links directly to the Indigo’s A2DP receiver.
The digital heart of the Indigo uses the latest generation of field programmable gate array devices (FPGA) as
found in the QBD76. The FPGA handles the switching of SPDIF inputs, all digital SPDIF decoding, digital PLL,
RAM buffer controller, WTA filtering, and the 5th generation Pulse Array DAC. The improvements to the Pulse
Array DAC have been further complimented with improved power supply design and layout giving the very best
digital to analogue conversion.
Digital inputs include SPDIF, AES, optical, USB, iPod and of course our latest developments with Bluetooth
audio. Using our custom designed Bluetooth receiver we have been able to extract the digital audio information
and input this directly into our DAC technology. Unlike the low quality audio seen from other Bluetooth devices
this gives us much better performance and enables CD like transfer of music from the Bluetooth device. Using
your A2DP equipped mobile phone or computer you can connect wirelessly to the Indigo.
As well as supporting digital connectivity the conveniently situated iPod dock features the standard analogue
connection and charging for use with any iPod. If you have the USB input connected to a personal computer then
you can also sync and transfer music to the connected iPod. There is an inbuilt USB hub with two additional front
panel connectors so that further devices can be connected to your computer via the Indigo.
An analogue input is provided for non digital sources via balanced XLR or RCA phono connectors and there are
both direct line level and volume controlled analogue outputs. Using the line level output AV Bypass is possible.
Headphone connectivity is available with a low distortion, low noise headphone output jack socket easily
accessible on the front panel.
Control is via the front panel or remote control and the large front panel display gives clear indication of settings
and digital frequencies.
Inventory
As well as your Indigo and this user manual, you should also have received the following items.
1. System Remote Control including user manual
2. Power cord
3. Chord guarantee registration card
4. USB Cable
5. Bluetooth adapter
7. 2x Antennas ( Aerials )
8. Ipod and digital ipod adapter ( Optional )

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When setting up
To ensure that your Indigo works efficiently and safely, please pay particular attention to the following issues.
Ventilation
Your Indigo should have at least 5cm of clear space all around it to ensure a free flow of air at all times. We do not
recommend that you place Indigo directly on a carpet.
AC lead and plug
All Chord equipment comes supplied with the correct power lead and plug. This should be used at all times.
If you need to fit a plug for UK/Europe
Connect the blue wire to the neutral terminal
Connect the brown wire to the live terminal
Connect the yellow/green wire to the earth terminal
If you need to fit a plug for US/Canada
Connect the white wire to the neutral terminal
Connect the black wire to the live terminal
Connect the green to the earth terminal
Earthing issues in Europe
In some European countries a hum may occur if your Indigo is connected to mains sockets that do not have an earth. If
this is the case please ensure that:
1. Your Chord unit is connected via a multi-way mains block, which contains an earth point
at each socket outlet. This is to ensure that the chassis metalwork of each item is
connected together.
2. We recommend that an earthing method for your building be implemented.
3. Use the connecting points on your Chord unit and connect to an available earth point.

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Safety Warnings
It is important that your Indigo is earthed at all times via its own mains lead. Failure to do this may be hazardous.
The power supply components within the Indigo are designed to operate at lethal voltages and energy levels.
Circuit designs that embody these components conform to applicable safety requirements. Precautions must be
taken to prevent accidental contact with power-line potentials. Do not connect grounded test equipment.
There are no user serviceable parts within the Indigo Reference Preamplifier. Unauthorised
tampering or dismantling of this product will invalidate the warranty and could cause injury.

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AC Power connection
The AC power connector of Indigo is at the back of the unit. Plug the female end (socket) of the power cord into
the power connector of the preamplifier, and the male end(plug) of the power cord into AC wall socket or AC
extension socket. The Indigo features a universal voltage high frequency power supply and will operate
automatically from 65V to 260V AC, 50 or 60Hz.
For optimum operation it is recommended that the Indigo is connected directly to the wall socket via the
power cord provided.
AC Connector
Powering up
Press the rear panel switch. The display and internal illumination will light up. The display will show the selected
input.
Powering down
Press the rear panel switch. The Indigo utilises soft start circuitry so the power can switched on and off as often as
required. There is no need to leave the Indigo permanently switched on but it can be if this is more convenient.
AC Connector
IEC 10A
EARTH

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Connecting your equipment
Chord amplifiers are supplied with and designed to be connected using balanced inputs. The interconnecting
cables you use will depend on the available input and output sockets on your other equipment. We have installed
unbalanced inputs on all Chord equipment, thus enabling you to mix Chord Electronics and other manufacturer’s
equipment.
Balanced inputs carry twice the strength of signal of unbalanced inputs and are able to be fed down long lengths of
cable with less deterioration of signal. They are also less prone to interference than unbalanced inputs. Balanced
inputs have three pins and use Neutric XLR style connectors. Pin 1 is earth, pin 2 is positive and pin 3 is negative.
Unbalanced inputs use RCA phono connectors, which are gold plated with teflon high performance dielectric
insulators for optimum performance.
Basic system diagram
1
2
3
outputs
inputs
CD Transport
Turntable
outputs
inputs
outputs
inputs
outputs
inputs
QBD76
SYMPHONIC
phono stage
power amplifier
pre-amplifier
speakers
-Amplfication
-Switching and
level control
-Data and
analogue
conversion
-Signal
Source
Red Reference
CD Player
CD Player

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Digital Input Connections
The Indigo features several types of digital input connection explained in more detail below.
USB
Using the cable provided connect this to an available USB port on your PC or MAC. Audio playback on the
computer will now be sent digitally via the USB connection to the Indigo. On some computers you may need to
change the audio settings and select USB DAC to activate this connection
Please also see the section on the USB hub for further functions.
DUAL COAX
The two coax BNC connectors can either be used independently or together for dual data operation. Connect your
CD transport or digital source to either of the two connectors for single data 44 to 96KHz operation. If you are
using the Blu or other CD transport that features dual data 176 or 192KHz operation please connect both
connectors so that the top connector connects to the top connector on the transport and the bottom to the bottom
connector.
AES1 & AES2
The two AES balanced digital connectors can either be used independently or together for dual data operation.
Connect your CD transport or digital source to either of the two connectors for single data 44 to 96KHz operation.
If you are using the Blu or other CD transport that features dual data 176 or 192KHz operation please connect both
connectors left to left and right to right.
OPT.1 & OPT.2
The Indigo features a newer high speed version of optical interface allowing for 192KHz via a single connection.
Connect your digital source via an optical cable to either of the two optical inputs. You can still use both
connectors for dual data operation if your source supports this.
IN
USB
DUAL
COAX
AES1
AES2
OPT.1
OPT.2

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Analogue Input Connections
The Indigo features an analogue input for connection to a non digital source. You can connect using balanced
cables or RCA phono cables.
Connect your analogue source to the input shown.
ANALOGUE
INPUTS