The ADI-8 DD commands any other format
or sample rate converter in the price-range up to $5,000 to their places,
with a single strike on the timps. Such a statement demands its proof - here
The ADI-8 DD consists of two (!) digital format converters with each up to
16 channels. It offers 34 different conversion modes, all with 24 bit resolution.
Besides the bi-directional conversion between all formats (ADAT/TDIF, ADAT/AES
or TDIF/AES), numerous additional modes are available. A simplified list
looks like this:
8-channel AES (4 x stereo,
XLR) to ADAT optical || TDIF converter (96 kHz)
8-channel AES to 2 x ADAT
|| 2 x TDIF splitter (48 kHz)
* ADAT || TDIF means that the
output signal is present in parallel, i.e. at the same time on the ADAT and
TDIF outputs. ADAT / TDIF means that the input can be either ADAT or TDIF.
Complicated? Not at all. The ADI-8 DD
is both easy to understand and easy to operate. More on the plain and simple
basic structure of the DD can be found here.
Because the ADI-8 DD is a dual converter,
there are two modes available at the same time from the modes mentioned above
- with few exceptions. Professionals are really thrilled by these features:
the ADI-8 DD understands Sample Split, S/MUX, Double Wire and Double Line.
It is thus compatible to all known methods for raising the sample rate by
sample distribution, on all supported platforms. Also multiple units can
be stacked and operated sample-aligned, using word clock.
Both converters work both completely independent and intelligently coupled.
The actual states of incoming and outgoing signals and ongoing operations
within the unit are displayed with LEDs of different colors in an easily
overseeable way. The 8-channel Sample Rate Converter
in Hi-End 24 bit/96 kHz quality is only available in the left or
right part of the device. It allows for a wide range of applications. When
the internal clock is used, the SRC works as a perfect jitter-killer.
And thanks to the SRC's clock-decoupling non-synchronizable items
like CD-players and DAT recorders can be used together as if they were synchronizable.
Devices from RME have an outstanding reputation. To maintain this, we keep
on looking for details that others miss. A present example is the ADI-8 DD's
SyncAlign® technology. As soon
as more than one AES or SPDIF input are used, there is usually the chance
of an accidental error of ± 1 sample misalignment between the stereo
inputs. SyncAlign prevents this error and guarantees sample synchronicity
between all 4 x 2 channels.
All of the ADI-8 DD's I/Os support 96kHz/24bit. As ADAT®
optical and TDIF are usually 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 the Hammerfall
Light. Thus the ADI-8 DD also represents an ideal AES/EBU frontend
for the Hammerfall series.
The compact device with 19" width and 1 HU has numerous exceptional
features like Intelligent
Clock Control (ICC) and storing of all settings.
Other highlights are:
inputs, 24 bit, using RME's unsurpassed bitclock PLL for sample accurate
Sample rate conversion 96
kHz/24 bit switchable for the AES/EBU inputs
Copy Mode allows for copying
data to an output of the same format (ADAT to ADAT etc.)
Clock decoupling (re-synchronization)
Active jitter reduction per
Serial Double PLL and SRC
Digital Patchbay, allows
for copying, duplicating and distributing of the digital input signals
SyncCheck®, unequalled technology
for checking of clock synchronicity
SPDIF mode switchable for
the second ADAT optical output
Compare the ADI-8 DD with other
stereo or multichannel converters and you will agree: the ADI-8 DD shows
an unsurpassed flexibility together with a sensational price point! It is
the long-awaited link in the semi-professional and professional area, from
project studio to broadcast applications.
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 digital input signals is displayed
by 16 LEDs. Shown are Lock (per XLR socket, 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
The ADAT/TDIF to AES section is laid
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 LEDs. 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, or both ADAT outputs can operate in parallel
to the AES outputs.
The unit always sends its output signal to ADAT and TDIF simultaneously.
Additionally when operating at no higher than 48 kHz 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.
The rear of the ADI-8 DD looks clear and tidy.
Two ADAT and TDIF I/Os each (for 8 channels @ 96kHz), word clock I/O and
four AES I/Os offer unbeatable flexibility and compatibility. Whatever it may
be - just make the connections and take off!
Jitter: Internal clock < 1 ns,
word clock In < 3 ns, ADAT In < 2 ns, TDIF In < 3 ns
Jitter sensitivity: all PLLs operate
even at 40 ns Jitter without problems
Jitter reduction: SD-PLL > 50%,
SRC > 99%
SRC dynamic ratio: 128 dB
SRC THD+N: < -117 dB (< 0.00014
Sample rate ratio: Max. 3:1 / 1:3
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
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