RME Audio ADI-8 DD User Manual
User's Guide
ADI-8 DD
SyncAlign®
SyncCheck®
Intelligent Clock Control
Hi-Precision 24 Bit / 96 kHz
8 Channel Dual Universal Format Converter
8 Channel Sample Rate Converter
ADAT® optical / TDIF®-1 / AES/EBU Interface
TM
TDIF-1
24 Bit Interface
Contents
1 Introduction....................................................................................................3
2 Supplied Contents .........................................................................................3
3 Brief Description and Characteristics...........................................................3
4 Technical Specifications ...............................................................................4
4.1 Inputs..........................................................................................................4
4.2 Outputs .......................................................................................................5
4.3 Digital..........................................................................................................5
4.4 Sample Rate Converter ...............................................................................5
5 First Usage
5.1 Quick Start..................................................................................................6
5.2 The DD plain and simple.............................................................................7
5.3 Operating the ADI-8 DD ..............................................................................8
6 The AES to ADAT/TDIF Converter
6.1 General.......................................................................................................9
6.2 Inputs..........................................................................................................9
6.3 Input State Display....................................................................................10
6.4 Sample Rate Conversion...........................................................................10
6.5 Outputs ADAT Optical/TDIF......................................................................11
6.6 Inputs ADAT/TDIF (Copy Mode) ................................................................12
7 The ADAT/TDIF to AES/EBU Converter
7.1 General.....................................................................................................13
7.2 Inputs........................................................................................................13
7.3 Input State Display....................................................................................14
7.4 Outputs AES/EBU.....................................................................................15
7.5 Input AES/EBU (Copy Mode) ....................................................................16
8 Clock Section
8.1 Clock Configuration...................................................................................17
8.2 Lock, SyncCheck and SyncAlign...............................................................18
8.3 Word Clock Input and Output....................................................................19
9 Word Clock
9.1 Operation and Technical Background........................................................20
9.2 Cabling and Termination ...........................................................................21
10 Conversion Modes and Notes
10.1 8-channel AES to ADAT || TDIF Converter (96 kHz) ...............................22
10.2 8-channel AES to 2 x ADAT || 2 x TDIF Splitter (48 kHz)........................22
10.3 2-channel AES to 8-channel TDIF || ADAT Splitter (96 kHz) ...................22
10.4 8-channel ADAT/TDIF to 2 x ADAT || 2 x TDIF Splitter (48 kHz).............22
10.5 16-channel ADAT/TDIF to ADAT || TDIF Converter (48 kHz)..................23
10.6 8-channel ADAT/TDIF to ADAT || TDIF Converter (96 kHz)....................23
10.7 8-channel TDIF/ADAT to ADAT || AES Converter (96 kHz).....................23
10.8 16-channel TDIF/ADAT to ADAT (|| AES) Converter (48 kHz).................23
10.9 8-channel AES to AES Sample Rate Converter (96 kHz)........................23
10.10 2-channel AES to 8-channel AES Splitter (96 kHz) .................................24
10.11 4-channel AES Double Wire to AES Single Wire Converter (96 kHz)......24
10.12 4-channel AES Single Wire to AES Double Wire Converter (96 kHz)......24
10.13 8-channel ADAT/TDIF to ADAT || TDIF Sample Rate Conv. (96 kHz).....24
11 Technical Background
11.1 DS – Double Speed ................................................................................25
11.2 AES/EBU – SPDIF..................................................................................26
11.3 Clock De-coupling using the SRC ...........................................................27
11.4 The SRC as Signal Conditioner...............................................................27
12 Controls and Connectors ............................................................................28
13 Connector Pinouts.......................................................................................29
14 Block Diagram..............................................................................................30
15 Warranty .......................................................................................................31
16 Appendix ......................................................................................................31
2
User's Guide ADI-8 DD © RME
1. Introduction
With the ADI-8 DD you have an incredibly versatile digital interface to your supply. What at first
looks like a simple AES/TDIF/ADAT format converter, turns out to be the universal problem
solver at a closer look. From small project studios to broadcast and television, the Universal
Format Converter is the perfect link between the formats mostly used today.
As a consequent continuation of RME's world-wide successful ADI-8 series, the DD also contains elaborate technology and the latest integrated circuits, delivering 8 full channels in 24 bit
and 96 kHz. The ADI-8 DD is a uniquely powerful and high-quality device, which will excite you
even after many years of operation.
2. Package Contents
Please check that your ADI-8 DD package contains each of the following:
• ADI-8 DD
• Manual
• Power chord
• 2 x 2 m optical cable (TOSLINK)
3. Brief Description and Characteristics
The ADI-8 DD consists of two 8-channel digital format converters in reference quality, in a standard 19" box with 1 unit height. The compact device has numerous extraordinary features like
Intelligent Clock Control (ICC), SyncCheck®, SyncAlign®, Bitclock PLL, patchbay functionality
and active jitter suppression per SD-PLL. Switchable high-end sample rate converters (SRC)
allow for both sample rate conversion in best possible quality, as well as clock-decoupling of all
AES/EBU inputs.
All of the ADI-8 DD's I/Os support 96 kHz/24 bit. As ADAT optical and TDIF are restricted to
48kHz, in DS mode (Double Speed) two channels are being used for the transmission of one
channel's data. The Sample Split algorithm used is also implemented in RME's Hammerfall and
Hammerfall DSP. Thus the ADI-8 DD also serves as an ideal AES/EBU frontend for these interface cards, on both Mac and PC.
The format conversion between AES/EBU and ADAT/TDIF operates in both directions at the
same time, both completely independent or intelligently coupled. LEDs of different colours
show the present state of incoming and outgoing signals and of the internal processing in a
clear way.
The unique Intelligent Clock Control (ICC) allows for a flexible use with internal clock (44.1, 48,
88.2 and 96 kHz), external word clock or the digital input signals. These options being available
for both directions are intelligently coupled in a way typical for RME and easy to apply thanks to
a clear and easily understandable display of the Lock and Sync states. Besides, the unique
Copy Mode allows for operation as digital patchbay and signal distributor. Up to 16 channels
can be distributed and converted at the same time. In few words: The ADI-8 DD is a true Intelli-
gent Audio Solution.
User's Guide ADI-8 DD © RME
3
4. Technical Specifications
• Power supply: Internal, 100-240 V AC, 15 Watts
• Dimensions: 483 x 44 x 205 mm
• Weight: 2 kg
4.1 Inputs
AES/EBU
• 4 x XLR, transformer balanced, ground-free, according to AES3-1992
• High-sensitivity input stage (< 0.3 Vss)
• SPDIF compatible (IEC 60958)
• Accepts Consumer and Professional format, copy protection will be ignored
• Single Wire: 4 x 2 channels 24 bit, up to 96 kHz
• Double Wire: 4 x 2 channels 24 bit 48 kHz, equalling 4 channels 96 kHz
• Lock range: 27 kHz – 103 kHz
• Jitter when synced to input signal: < 3 ns
ADAT Optical
• 2 x TOSLINK, according to Alesis specification
• Standard: 8 channels 24 bit, up to 48 kHz
• Copy Mode: up to 2 x 8 channels 24 bit / 48 kHz
• Sample Split (S/MUX): 2 x 8 channels 24 bit / 48 kHz, equalling 8 channels 24 bit 96 kHz
• Bitclock PLL ensures perfect synchronisation even in varispeed operation
• Lock range: 33 kHz – 56 kHz
• Jitter when synced to input signal: < 2 ns
TDIF
• 2 x D-sub 25 pol., according to TDIF-1
• Standard: 8 channels 24 bit, up to 48 kHz
• Copy Mode: up to 2 x 8 channels 24 bit / 48 kHz
• Sample Split (Dual Line): 2 x 8 channels 24 bit / 48 kHz, equalling 8 channels 24 bit 96 kHz
• SD-PLL for low jitter synchronisation even in varispeed operation
• Lock range: 27 kHz – 56 kHz
• Jitter when synced to input signal: < 3 ns
Word Clock
• BNC, not terminated (10 kOhm)
• Automatic Double Speed detection and internal conversion to Single Speed
• SD-PLL for low jitter synchronisation even in varispeed operation
• AC-coupling, not effected by DC-offsets within the network
• Signal Adaptation Circuit: signal refresh through auto-center and hysteresis
• Overvoltage protection
• Level range: 1.0 Vss – 5.6 Vss
• Lock range: 27 kHz – 112 kHz
• Jitter when synced to input signal: < 3 ns
4
User's Guide ADI-8 DD © RME
4.2 Outputs
AES/EBU
• 4 x XLR, transformer balanced, ground-free, according to AES3-1992
• Output voltage Professional 4.5 Vss, Consumer 2.1 Vss
• Format Professional according to AES3-1992 Amendment 4
• Format Consumer (SPDIF) according to IEC 60958
• Single Wire: 4 x 2 channels 24 bit, up to 96 kHz
• Double Wire: 4 x 2 channels 24 bit 48 kHz, equalling 4 channels 96 kHz
ADAT Optical
• 2 x TOSLINK
• Standard: 8 channels 24 bit, up to 48 kHz
• Copy Mode: up to 2 x 8 channels 24 bit / 48 kHz
• Sample Split (S/MUX): 2 x 8 channels 24 bit / 48 kHz, equalling 8 channels 24 bit 96 kHz
TDIF
• 2 x D-sub 25 pin, according to TDIF-1
• Standard: 8 channels 24 bit, up to 48 kHz
• Copy Mode: up to 2 x 8 channels 24 bit / 48 kHz
• Sample Split (Dual Line): 2 x 8 channels 24 bit / 48 kHz, equalling 8 channels 24 bit 96 kHz
Word Clock
• BNC
• Max. output voltage: 5 Vss
• Output voltage @ 75 Ohm: 4.0 Vss
• Impedance: 10 Ohm
• Frequency range: 27 kHz – 56 kHz
4.3 Digital
• Low Jitter Design: < 1 ns internal
• Internal sample rates: 44.1 kHz, 48 kHz, 88.2 kHz, 96 kHz
• Internal resolution: 24 bit
4.4 Sample Rate Converter
• Self adjusting, high order aliasing filter (-110 dB)
• Resolution: 24 bit
• Dynamic range: 128 dBA
• Distortion (THD+N): -117 dB (0.00014%)
• Input / Output sample rate range: 27 kHz - 103 kHz
• Supports varispeed operation through fast tracking
User's Guide ADI-8 DD © RME
5
5. First Usage
5.1 Quick Start
The user interface of the ADI-8 DD is characterized by a clearly structured architecture and an
unambiguous labelling of the front and rear sides. The device can thus be used easily without a
manual, because numerous LEDs show the state of the device and of all incoming and outgoing signals in a strictly logical way.
However, we have to question this statement a little, because we couldn't stop ourselves and
integrated everything in the ADI-8 DD that we could think of and that was in any way possible.
As a consequence, you will find some application examples in chapter 10 that break up the
logical structure of the front board. Those are however very special applications for professionals, where we anticipate both the understanding of those modes and the ability to read a manual.
When being switched on for the first time, the ADI-8 DD comes up in a default mode, which
should be appropriate for most applications. Both converters are set to their typical format conversion modes, and synchronize to the input signals.
AES to ADAT/TDIF:
• SOURCE: AES
• SRC not active
• Slave mode (CLOCK AES / INPUT)
ADAT/TDIF to AES:
• SOURCE: ADAT
• Slave mode (CLOCK ADAT / INPUT)
• AES STATE PRO
If the device is being used with TDIF, simply select SOURCE TDIF instead of ADAT in the right
part.
The ADI-8 DD remembers all settings before switching off and sets them automatically when
switching on the next time.
A quick guide for operation and functionality of the ADI-8 DD can be found on the next pages.
For transmission of the digital signals into a computer with PCI-bus, we recommend RME's
interface cards of the DIGI96® and Hammerfall® series. These high quality digital audio cards
are available with drivers for all common operating systems, and have the highest reputation
world-wide.
6
User's Guide ADI-8 DD © RME
5.2 The DD plain and simple
With a device as powerful as the ADI-8 DD, it is for sure sometimes difficult to find out what's
going on, or can be done with it. The device is capable of 34 different format conversions –
which nobody can remember. And how are they set up? What can the user do at all?
The key to understanding the ADI-8 DD is the block diagram below. Reduced to the core functionality, it shows clearly and easily to be understood, which inputs and outputs work together
where and when.
The three inputs AES, ADAT and TDIF are shown on the left side. Using one source switch
each, both the left and the right part can access the inputs independently. The output of the left
part is connected to TDIF, and basically also to the ADAT output. The output of the right part is
connected to the AES output. This is the obvious design and functionality of the device, as can
be learned from the front panel and the rear (connectors). The two converter units of the ADI-8
DD operate independently from each other, no matter which of the three inputs they use, sending a signal to their hard-wired outputs.
But there are two special cases, in which the optical ADAT outputs work for the right part instead of the left part. Using the AES STATE key, the AES signal can also be routed to the optical output*. This functionality is activated by switch Opt.2 in the diagram. It is very useful when
a device shall be connected which has only an optical SPDIF input (e.g. Mini-Disc).
The second special function enables an 'ADAT to TDIF and vice versa' converter, i.e.
ADAT/TDIF in both directions simultaneously. So far, the ADI-8 DD can be used bi-directional
as AES to TDIF and AES to ADAT converter. But ADAT to TDIF, as well as TDIF to ADAT, are
both a function of the left part, therefore require to change the input and are thus not available
at the same time. As can be seen in the block diagram the ADAT output can also be fed from
the right part, activated by switch Opt.1 in the diagram. The conversion TDIF to ADAT now
takes place in the right part, and the ADI-8 DD can convert ADAT/TDIF in both directions at the
same time.
*The AES output 1/2 is sent to the second ADAT output AUX.
User's Guide ADI-8 DD © RME
7
5.3 Operating the ADI-8 DD
Join us for a small 'tour de ADI', starting on the left side at the AES to ADAT/TDIF converter.
Configuration starts with choosing the input signal (AES, ADAT or TDIF). The state of the input
signal is displayed by 16 LEDs. Shown are Lock (per XLR jack, including SyncCheck), Emphasis and the level of the audio signal.
SRC activates a Hi-End 8-channel Sample Rate Converter. It is especially useful when sources
cannot be synced, or the output signal shall have another sampling frequency.
RME's intelligent clock control (ICC) offers extensive and professional means that are not easily met. To start with, the clock source can be set to Internal (crystal), External (BNC word
clock) and Input, while Input lets you select between AES, ADAT or TDIF. The INT(ernal) clock
rates are 44.1 and 48kHz, which turn to 88.2 and 96kHz after activating the DS mode. After
activating SRC, any AES signal from 32 to 96kHz can be converted to 44.1, 48, 88.2 or 96kHz.
Lock state and clock synchronicity are being displayed by the state of each LED (flashing or
constantly lit).
The ADAT/TDIF to AES section is layed out in a similar way. After choosing the input signal
(AES, ADAT or TDIF), the clock source and the sampling rate, there is a field with 16 LEDs for
displaying the current status. An Emphasis bit at the TDIF input will be automatically set and
indicated for the AES out. The Lock state of the input signals is being displayed at the
SOURCE selector by flashing LED. The Sync LEDs show the synchronicity between both
ADAT or TDIF inputs (or the four XLR inputs), as in double speed mode (DS) 2 I/Os are active
(4 channels each).
The AES output signal can be set to Consumer or Professional subcode. The first output
(channel 1/2) can optionally be output optically (via TOSLINK) using the second ADAT output.
The AES STATE key also allows to connect both ADAT outputs to the AES outputs (OPT. blinking; useful for TDIF to ADAT conversion).
The unit always sends its output signal to ADAT and TDIF simultaneously. Additionally when
operating at no higher than 48kHz, both ADAT outputs and TDIF interfaces get the same signal. Thus the distribution capability is doubled to 2 x ADAT and 2 x TDIF. Thanks to the freely
available inputs all attached devices can send signals to each other without the need to rearrange the cabling between them.
8
User's Guide ADI-8 DD © RME
6. The AES to ADAT/TDIF Converter
6.1 General
This ADI-8 DD's functional unit, which will be called 'left part' further on, is an 8-channel format
converter from AES, TDIF or ADAT to ADAT/TDIF, with the output signal being transmitted
both at the ADAT and TDIF ports in parallel. As long as the device is not working in DS mode
(Double Speed), the output signal is even present at both ADAT and TDIF ports (MAIN/AUX).
Therefore the ADI-8 DD can pass on a 4 x 2 channel AES/EBU input signal to up to two ADAT
and TDIF devices at the same time (splitter 1 to 4). If AES is chosen as source in the right part,
the signal will additionally be passed on to the four AES/EBU outputs as well.
The four AES/EBU inputs process Double Speed (up to 96 kHz) and Double Wire (up to 48
kHz) automatically. Excessive status displays (Lock, SyncCheck, Emphasis, Level) help to
avoid wrong configuration and wrong clock setup.
A switchable high-end 8-channel sample rate converter can both convert the sample rate and
decouple the AES/EBU inputs.
6.2 Inputs
At the rear side of the ADI-8 DD there are four XLR sockets for the AES/EBU inputs. Every
input is transformer-balanced and ground-free. Channel status and copy protection are being
ignored. Thanks to a highly sensitive input stage, also SPDIF signals can be processed by using a simple cable adapter (Phono/XLR).
To achieve this, pins 2 and 3 of an
XLR plug are being connected to
the two contacts of a Phono plug.
The ground shield of the cable is
only connected to pin 1 of the XLR
plug.
The inputs can be used in any combination, e. g. it is sufficient to connect an input signal only
to input 3. In slave mode, this input is automatically being used as clock source. If more than
one signal is present, the one furthest left is being used as clock source, i. e. the active input
with the lowest number.
The inputs are being copied to the 8 channel ADAT/TDIF formats in logical order:
AES/EBU Input 1 2 3 4
ADAT/TDIF MAIN+AUX 1/2 3/4 5/6 7/8
If an input sample rate higher than 56 kHz is detected at the AES/EBU input, the DS LED lights
up and the left part automatically switches to DS mode, using the following channel distribution:
AES/EBU 1L 1R 2L 2R 3L 3R 4L 4R
ADAT/TDIF 1/2
MAIN
If a signal in Double Wire format is present at the input, technically no special processing is
activated, because the output signals will be in Sample Split format (S/MUX, Double Line) right
away.
3/4
MAIN
5/6
MAIN
7/8
MAIN
1/2
AUX
3/4
AUX
5/6
AUX
7/8
AUX
User's Guide ADI-8 DD © RME
9
6.3 Input State Display
The input state is displayed by 16 LEDs. Every input has its own SYNC LED. However a missing or invalid input signal is indicated by slow flashing of the SOURCE LED. As soon as a valid
input signal is present the four SYNC LEDs will react per input. If ADAT or TDIF are chosen as
input source, all four SYNC and Emphasis LEDs show the same information. In DS mode, both
two and two LEDs show the state of the MAIN (1/2) and the AUX (3/4) inputs.
If a valid input signal is applied, SyncCheck is active automatically. When more than one input
signal is present, the input with the lowest number serves as reference. If the AES input is not
chosen as clock source, SyncCheck takes the chosen clock as reference and compares it with
the input clocks. Inputs which are not synchronous will be signalled by quick flashing of the
corresponding SYNC LED.
AES/EBU, SPDIF and TDIF can contain an Emphasis information. Audio signals with Emphasis
have a strong high frequency boost and thus require a high frequency attenuation on playback.
If one of the inputs detects Emphasis, this information is being set at the TDIF output (and being transmitted correctly to a DTRS machine). Note that the alerting red colour of the Emphasis
LEDs has a reason:
Emphasis is not available within the ADAT standard! This information is thus neither passed
on to the ADAT output, nor taken into account later on for acoustic transmission!
Each channel's audio level is shown by a LEVEL LED. The green LED becomes active from 90 dBFS and above, a higher level yields brighter light. Thus only one LED is necessary to see
if there is an audio signal or digital zero, only noise floor or a meaningful signal.
6.4 Sample Rate Conversion
Each AES/EBU input has its own sample rate converter (SRC). An SRC allows for a conversion
of the sampling rate in real-time. The 24 bit SRCs used in the ADI-8 DD work virtually without
loss, i. e. there are no audible artefacts or noise signals. The SRC works so well that we could
recommend to leave it switched on all the time, and thus eliminate any clock problem in the
first place.
The ADI-8 DD's SRC yields a maximum conversion ratio of 3:1 or 1:3. 96 kHz can be converted to any sample rate down to 32 kHz, 32 kHz to any rate up to 96 kHz.
If the internal clock is being used, the SRC works as a perfect jitter killer. But the ADI-8 DD
allows for any source as clock reference (except AES/EBU). With other settings than INT, the
device is slave as usual, and the jitter of the output signal thus is depending on the jitter of the
clock source.
An SRC is not only being used for conversion of sample rates and jitter suppression, it is especially useful for the so-called clock decoupling. By means of an SRC, any device which can't be
synchronized (CD-Player, consumer DAT etc.) can be used within a digital audio network as if it
was synchronizable. The SRC decouples any input clocks and sets the output clock to the
common reference (no matter which one), thus allows for bringing together various clock
sources without any clicks or drop-outs.
Further information on sample rate conversion can be found in chapter 11, Technical Background.
10
User's Guide ADI-8 DD © RME
Loading...