Cedar DC-1 De-Clicker User manual

DC-1 SERIES 2: Rev.02 Ver.3.06 Page - 1
CEDAR
Professional Hardware Systems
DC-1 De-Clicker
Digital Audio Restoration System
SERIES 2
0
2
4
6
8
10
12
Output Attenuation
CEDAR Audio Ltd
A member of the
Association of Professional Recording Services
CEDAR De-Clicker DC 1
Phones
Level
Power
Input Level Contrast
Enter
Bypass Page
Pre/Post
Digital
44.1kHz
48kHz
Bypass
Pre
Post
Over
0dB
-40
-20
-10
Over
0dB
-40
-20
-10
SERIES 2
OWNER'S MANUAL
© 1994 CEDAR Audio Ltd. Written by Gordon Reid
interstage
Phistersvej 31, 2900 Hellerup, Danmark
Telefon [phone], fax [phone]
www.interstage.dk
-pro audio with a smile

DC
-1 SERIES 2: Rev.02 Ver.3.06 Page - 2
TABLE OF CONTENTS
TABLE OF CONTENTS............................................................................................................................................2
INTRODUCTION.........................................................................................................................................................3
THE BACKGROUND TO SCRATCH REMOVAL ..............................................................................................4
SAFETY INSTRUCTIONS........................................................................................................................................5
SET UP .........................................................................................................................................................................7
UNPACKING AND INSPECTION ............................................................................................................................7
INSTALLATION SITE ...............................................................................................................................................7
RACK MOUNTING ...................................................................................................................................................7
FREE STANDING USE............................................................................................................................................7
CONNECTIONS..........................................................................................................................................................8
BEFORE CONNECTION .........................................................................................................................................8
POWER CONNECTIONS ........................................................................................................................................8
SIGNAL LEAD CONNECTIONS .............................................................................................................................8
OTHER CONNECTIONS .......................................................................................................................................10
SAMPLE INSTALLATION IDEAS .......................................................................................................................11
A GUIDE TO RESTORATION PROCESSING..................................................................................................12
FRONT PANEL INDICATORS AND CONTROLS ...........................................................................................14
QUICK TOUR ............................................................................................................................................................16
WARMSTART AND COLDSTART ......................................................................................................................17
OPERATING THE CEDAR DC-1 SERIES 2 .....................................................................................................18
DEDICATED CONTROLS .....................................................................................................................................18
PAGES ...................................................................................................................................................................20
Control Page ....................................................................................................................................................21
Input/Output Control Page ............................................................................................................................23
Remote Control ...............................................................................................................................................27
STATUS PAGE ...............................................................................................................................................28
STATUS INDICATORS.................................................................................................................................28
NOTES AND HINTS TO USERS..........................................................................................................................31
REMOTE CONTROL PROTOCOLS ...................................................................................................................32
RS232.....................................................................................................................................................................32
MIDI.........................................................................................................................................................................34
SELF TEST MODE ..................................................................................................................................................35

DC
-1 SERIES 2: Rev.02 Ver.3.06 Page - 3
INTRODUCTION
Thank you for purchasing the CEDAR DC-1 De-clicker. The original DC-1 was the
world's first real-time dedicated digital de-clicking device, and the DC-1 SERIES 2
offers even greater processing power and performance - power exceeding that
obtained using digital signal processors (DSPs) installed in desk-top or larger
computer systems (excepting, of course, the CEDAR Production Systems).
The DC-1 SERIES 2 is designed for professional use, although it will work perfectly
well in a domestic environment, and its features include the following:
• The latest 'SERIES-2' CEDAR hardware.
• Digital Audio interfaces conforming to the AES/EBU and SP-DIF standards.
• 24-bit input and output resolution when using AES/EBU interfaces
• Three sample rates supported on digital inputs: 32kHz, 44.1kHz and 48kHz
• Two sample rates supported on analogue inputs: 44.1kHz and 48kHz
• Balanced analogue inputs and outputs for connection to professional
analogue equipment.
• ADC and DAC converters using the latest 64x over-sampling ∆-∑(Delta-
Sigma) technology.
• >103dB dynamic range A/D and >93dB dynamic range D/A
• Mountable in a 19" EIA rack.
• Remote control via MIDI and RS232 interfaces.
• SMPTE/EBU timecode capabilities via optional upgrade
• Input and output LED bar-graph VU meters.
• Twin 40-bit floating-point DSP processors delivering 50MFlops to handle the
most complex audio processing requirements.
• High levels of artificial intelligence designed into the DC-1 program algorithms
making it extremely simple to use.

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-1 SERIES 2: Rev.02 Ver.3.06 Page - 4
THE BACKGROUND TO SCRATCH REMOVAL
The term 'scratch' describes many different audio phenomena - ticks, pops, clicks,
crackle and thumps - as well as genuine scratch-like artefacts. However, when
analysed carefully, each of these degradations displays different sonic
characteristics. Therefore, a single process attempting to remove all of these
impulses would be an unacceptable compromise, incapable of total repair of any
single category.
These degradations can be separated into three categories: thumps (which includes
loud pops), scratches (including ticks and clicks), and crackle. The DC-1 SERIES 2
has been designed to perform real-time scratch removal.
The operation of the DC-1 is digital, and any signal presented to the analogue inputs
is internally converted to a suitable digital format by the integrated high quality
analogue-to-digital converter (ADC). Following click removal the processed signal is
converted back from digital format to analogue by the digital-to-analogue converter
(DAC).
For use with records, films, video, and tape, no other device offers the power,
facilities, or accuracy of the DC-1 SERIES 2.

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-1 SERIES 2: Rev.02 Ver.3.06 Page - 5
SAFETY INSTRUCTIONS
CAUTION:
1. Read all of these instructions
All safety and operating instructions should be read before the DC-1 SERIES
2is operated.
2. Save these instructions for future reference.
3. Follow all warnings and instructions.
4. Water and Moisture
The DC-1 SERIES 2 should not be used near water, and must not be
exposed to rain or moisture. If the DC-1 is brought directly from a cold
environment into a warm one, moisture may condense inside the unit. This, in
itself, will not damage the DC-1, but may cause hazardous electrical shorting
to occur. This could severely damage the DC-1 and even cause danger to
life. ALWAYS allow time for the DC-1 to reach ambient temperatures before
connecting the mains power.
5. Mounting
The DC-1 SERIES 2 should be carefully mounted in a 19" EIA rack, or placed
on a flat, stable surface. If used on a cart or free stand, care should be taken
when moved: uneven surfaces or excessive force may cause cart and DC-1
to overturn. Do not position the DC-1 in a place subject to strong sunlight,
excessive dust, mechanical vibration or periodic shocks.
6. Wall or Ceiling Mounting
The DC-1 SERIES 2 has not been designed for mounting directly to walls or
ceilings.
7. Ventilation
Good air circulation is essential to prevent internal heat built-up within the DC-
1 SERIES 2. The DC-1 should be situated so that its position does not
interfere with proper ventilation. The DC-1 should not be placed in any
situation that impedes the flow of air through the vents at the front and rear.
Do not place the DC-1 on a soft surface.
8. External Heat Sources
The DC-1 SERIES 2 should be installed away from significant heat sources
such as radiators, and (if possible) away from other audio devices such as
amplifiers that produce large amounts of heat. Installation in racks with
devices such as signal processors or tape machines should not be a problem.

DC
-1 SERIES 2: Rev.02 Ver.3.06 Page - 6
9. Power Sources
The DC-1 SERIES 2 features an auto-switching power supply which will work
safely on any mains supply in the ranges 95v/130v and 190v/260v, 50Hz or
60Hz AC only.
You should never attempt to modify or adjust the internal power supply
in any way. It contains no user serviceable parts.
10. Grounding or Polarisation
The DC-1 SERIES 2 should always be grounded (or 'earthed').
11. Power Cord Protection
Power connectors should be routed so that they will not be walked on or
pinched.
12. Extended Periods of Non-Use
The DC-1 SERIES 2 is not disconnected from the mains power as long as it is
connected to the wall outlet, even if the unit itself has been switched off.
Therefore, if the DC-1 is not used for an extended period, unplug the unit from
the wall. Pull the connector out by the plug, never by the cord itself.
13. Cleaning
Clean only with a dry cloth. NEVER use liquid cleaners such as alcohol or
benzene on the DC-1 SERIES 2. NEVER use abrasive pads on the DC-1.
14. Damage Requiring Service
The DC-1 SERIES 2 should be returned to qualified service personnel when:
• objects have fallen into the unit
• liquid has spilled into the unit
• the unit has been exposed to rain
• the unit fails to function or appears to operate abnormally
• the unit has been dropped, or the case damaged.
15. Servicing
The user should not attempt to service the DC-1 SERIES 2 beyond the
instructions contained in the User's Manual. All other servicing should be
referred to qualified service personnel.

DC
-1 SERIES 2: Rev.02 Ver.3.06 Page - 7
SET UP
1. UNPACKING AND INSPECTION
Be careful not to damage the DC-1 SERIES 2 during unpacking. Save the
carton and all packing materials since you may need them to transport the
DC-1 SERIES 2 in the future.
In addition to the packaging, the carton should contain the following:
• mains connection lead
• this manual
2. INSTALLATION SITE
The DC-1 SERIES 2 may be used in most areas, but to maintain reliability
and prolong operating life observe the following environmental
considerations:
• Nominal temperature should be maintained between 5˚ and 35˚
Centigrade (41˚ and 95˚ Fahrenheit).
• Relative humidity should be in the range 30% to 60% non-condensing.
• Strong magnetic fields should not exist nearby.
3. RACK MOUNTING
The DC-1 SERIES 2 can be mounted in a standard 19" EIA rack.
4. FREE STANDING USE
The DC-1 SERIES 2 can be used as a freestanding unit. The blanking plates
may then replace the rack-mount ears if desired.
To replace the ears with the blanking plates:
• Unscrew the three bolts that attach each ear to the chassis of the DC-
1.
• Attach the blanking plates using the same retaining bolts. Do not over-
tighten these bolts as doing so may cause damage to the DC-1.

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-1 SERIES 2: Rev.02 Ver.3.06 Page - 8
CONNECTIONS
The DC-1 SERIES 2 may be connected to most of the professional audio equipment
currently available. Three types of audio input and output are provided (one
analogue and two digital) and these will satisfy most users' interconnection
requirements. Full descriptions of these connectors will be found later in the manual.
1. BEFORE CONNECTION
• To prevent problems and possible equipment damage, turn off the
power to all equipment before making connections.
• Be sure to insert plugs firmly into sockets. Loose connections may
cause hum and noise.
• When unplugging any lead, do so by grasping the plug, not the lead.
2. POWER CONNECTIONS
Ensure that the DC-1 SERIES 2 is switched OFF before inserting the mains
lead.
NOTE: Users with 2-pin mains supplies:
When the DC-1 SERIES 2 is connected to other audio components, the AC
hum of the unit may be increased or decreased by reversing the direction of
the power connector in the socket. Check that the cord is in the favourable
position ('in-phase') with respect to other audio devices in the chain. This will
ensure that you obtain the best sound quality from your DC-1.
For further information on grounding and polarity, consult a person familiar
with studio grounding techniques.
3. SIGNAL LEAD CONNECTIONS
Refer to the Rear Panel diagram:
The DC-1 SERIES 2 offers three audio connection standards: one analogue
and two digital. These are:
• balanced analogue audio I/O
• digital SP-DIF format audio data
• digital AES/EBU format audio data
Note that the DC-1 SERIES 2 always passes its output to all three signal
outputs irrespective of the input used, but that the digital data will only be
formatted for either AES/EBU or SP-DIF, as defined by the user parameters.

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-1 SERIES 2: Rev.02 Ver.3.06 Page - 9
(i) Balanced analogue audio I/O (Pin 2 - 'hot')
This standard is used in professional audio equipment. Connect the
output from your source to the balanced analogue inputs of the DC-1
SERIES 2 using standard XLR plugs. You will require two such
connections: one for each channel.
The balanced audio output may be used to connect the DC-1 SERIES
2directly to audio equipment such as mixing desks and professional
recorders featuring balanced XLR inputs and outputs.
(ii) Digital SP-DIF format audio data
The SP-DIF format is used by domestic and semi-professional digital
audio devices such as DAT machines, some ADCs, and some CD
players. Both audio channels are carried along a single cable, so you
may connect the SP-DIF output from your source to the SP-DIF input
of the DC-1 SERIES 2 using a single cable terminated with RCA (or
'phono') plugs.
The SP-DIF output of the DC-1 SERIES 2 may be connected to the
SP-DIF input of your recording device or external DAC.
(iii) Digital AES/EBU format audio data
The digital AES/EBU format is used by professional digital audio
devices including mastering systems, DASH recorders, and high
quality ADCs & DACs. Both channels of audio are carried along a
single cable, so you may connect the AES/EBU output from your
source to the AES/EBU input of the DC-1 SERIES 2 using a single
cable terminated with XLR plugs.
The AES/EBU output of the DC-1 SERIES 2 may be connected to the
AES/EBU input of your digital mixer, recording device or external DAC.
24-bit Digital data resolution:
The DC-1 SERIES 2 features 24-bit input and output resolution
whenever the AES/EBU digital input and output are utilised.
Dithering:
The DC-1 SERIES 2 also features TPDF (Triangular Probability
Density Function) dithering. This is applied to the digital data when the
SP-DIF output format is selected. Dithering is always applied to the
data presented to the DACs.

DC
-1 SERIES 2: Rev.02 Ver.3.06 Page - 10
In order to comply fully with EMC regulations, this unit should be connected
via its AES/EBU and/or analogue connectors. Metal-shelled XLR connectors
should be used. We recommend using a good quality ‘starquad’ cable, with
three cores connected to pins 1, 2 & 3. The shield of the cable should be
connected, at both ends, to the outer shell of the connector.
4. OTHER CONNECTIONS
(i) SMPTE/EBU
An optional SMPTE/EBU interface offering LTC and VITC protocols is
available for the DC-1 SERIES 2. The standard DC-1 SERIES 2 does
not support timecode and these connectors are not present.
(ii) MIDI IN/OUT/THRU
The operation of the DC-1 SERIES 2 may be controlled using the
Musical Instrument Digital Interface (MIDI). Refer to the chapter on
Remote Control Protocols for further instructions.
(iii) RS232
The DC-1 SERIES 2 may be controlled using the standard RS232
serial communications protocol. Refer to the chapter on Remote
Control Protocols for further instructions.