User's Guide ADI-192 DD SyncAlign ™ ™ SyncCheck Intelligent Clock Control ™ ™ SteadyClock Hi-Precision 24 Bit / 192 kHz 8-Channel Triple Universal Format Converter 8-Channel Sample Rate Converter ADAT® optical - TDIF™ - AES/EBU Interface TDIF-1 24 Bit Interface
General 1 2 3 4 Introduction ...............................................................6 Package Contents .....................................................6 Brief Description and Characteristics.....................6 First Usage - Quick Start 4.1 Controls and Connectors .......................................7 4.2 Quick Start .............................................................8 4.3 The DD plain and simple........................................9 5 Warranty................................
Important Safety Instructions ATTENTION! Do not open chassis – risk of electric shock The unit has non-isolated live parts inside. No user serviceable parts inside. Refer service to qualified service personnel. Mains • The device must be earthed – never use it without proper grounding • Do not use defective power cords • Operation of the device is limited to the manual • Use same type of fuse only To reduce the risk of fire or electric shock do not expose this device to rain or moisture.
User's Guide ADI-192 DD © RME
User's Guide ADI-192 DD General User's Guide ADI-192 DD © RME 5
1. Introduction With the ADI-192 DD you have an incredibly versatile digital interface to your supply. The successor of the highly successful ADI-8 DD is a completely re-engineered device, designed to be the most powerful format and sample rate converter ever. What at first looks like a simple AES/TDIF/ADAT format converter, turns out to be the universal problem solver at a closer look.
4. First Usage – Quick Start 4.1 Controls and Connectors The front of the ADI-192 DD features nine buttons and 48 LEDs, providing all necessary means for a detailed configuration of the unit, plus an optical SPDIF I/O with TOSLINK connectors. INPUT MONITOR indicates a valid input signal separately for each digital input. Additionally, RME's exclusive SyncCheck indicates if one of these inputs is locked, but not synchronous to the others. See also chapter 5.1 and 11.2.
4.2 Quick Start In the INPUT MONITOR section 19 LEDs provide detailed information about the status of the digital input signals. Displayed are Lock (flashing) and Sync (constantly lit), the frequency range (Double or Quad Speed), a possible S/MUX indication on the ADAT input (DW), and the presence of audio data within the signal (Level). SRC INPUT SOURCE is used to select the input signal of the sample rate converter.
4.3 The DD plain and simple The user interface of the ADI-192 DD is characterized by a clearly structured architecture and an unambiguous labelling of the front and rear sides. Numerous LEDs show the state of the device and of all incoming and outgoing signals in a strictly logical way. A simplified block diagram of the ADI-192 DD shows in an easy to understand way, how the different format converters work together and how they can be used in practice.
5. Warranty Each individual ADI-192 DD undergoes comprehensive quality control and a complete test at IMM before shipping. . The usage of high grade components should guarantee a long and trouble-free operation of the unit. If you suspect that your product is faulty, please contact your local retailer. Audio AG grants a limited manufacturer warranty of 6 months from the day of invoice showing the date of sale. The length of the warranty period is different per country.
CE / FCC Compliance CE This device has been tested and found to comply with the limits of the European Council Directive on the approximation of the laws of the member states relating to electromagnetic compatibility according to RL2004/108/EG, and European Low Voltage Directive RL2006/95/EG. FCC This equipment has been tested and found to comply with the limits for a Class B digital device, pursuant to Part 15 of the FCC Rules.
User's Guide ADI-192 DD © RME
User's Guide ADI-192 DD Usage and Operation User's Guide ADI-192 DD © RME 13
5. Front panel Controls 5.1 INPUT MONITOR The status of the inputs is displayed by 19 LEDs. The section INPUT MONITOR helps to avoid errors caused by wrong, missing or not correctly connected inputs, and makes handling the digital formats much easier. General Each input has its own SYNC LED. 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.
The function RANGE tells the SRC which frequency its input signal has. The frequency of its output signal (the frequency the input signal shall be converted to) is defined in the CLOCK SECTION. More information is found in chapter 8, Sample Rate Converter. 5.3 CLOCK SECTION The source and frequency of the unit's clock is configured in the CLOCK SECTION. The button CLOCK lets you step through the options external clock (AES, TDIF, ADAT, word) and internal clock (44.1 or 48 kHz).
Activation of Follow Clock: while the firmware version is shown press the CLOCK STATE button. Both LEDs DS/QS light up. Deactivation: same, both LEDs stay dark. 5.4 AES OUTPUT The input signal of the AES outputs is selected in the OUTPUT section. With no LED lit (no input selected) the unit provides an empty frame signal of the current sample frequency. A flashing LED indicates an invalid or missing input signal.
6. Inputs 6.1 AES/EBU At the rear side of the ADI-192 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 a male XLR plug are connected individually to the two pins of a phono plug.
6.2 TDIF The ADI-192 DD has two TDIF-1 ports. In standard operation only the port labelled MAIN is used. Higher sample rates than 48 kHz are realized by sample multiplexing. When using more than four channels at Double Speed or two channels at Quad Speed, the port labelled AUX has to be used as well. The TDIF-1 connectors of the ADI-192 DD are fully compatible with all devices offering such an interface*. RME's exclusive SyncCheck verifies synchronous operation when using both TDIF ports.
6.3 ADAT Optical The ADI-192 DD has two ADAT optical inputs. In standard operation only the port labelled MAIN is used. Higher sample rates than 48 kHz are realized by sample multiplexing. When using more than four channels at Double Speed or two channels at Quad Speed, the port labelled AUX has to be used as well. The ADAT optical inputs of the ADI-192 DD are fully compatible with all ADAT optical outputs.
7. Outputs 7.1 AES/EBU At the rear side of the ADI-192 DD there are four XLR sockets as AES/EBU outputs. Each output is transformer-balanced, ground-free and compatible to all devices with AES/EBU ports. Connection is accomplished using balanced cables with XLR plugs. If AES STATE PRO (Professional) is chosen, the output level is almost 5 Volt. If CON (Consumer) is chosen, the output signal will have a channel status compatible to SPDIF.
The outputs of the ADI-192 DD support all currently known formats in the range of 32 kHz up to 192 kHz. The current output format is defined by the button STATE in the AES OUTPUT section: • Single Wire (no LED): 8 channels 32 kHz – 192 kHz. 2 channels per AES wire. The effective sample frequency equals the clock on the AES wire. • Double Wire (LED DW): 4 channels 88.2 kHz – 192 kHz. 1 channel per AES wire. The effective sample frequency is double the clock of the AES wire.
7.3 ADAT Optical The ADI-192 DD provides two digital outputs in ADAT optical format. In standard operation only the port labelled MAIN is used. The port AUX is operated synchronously, but does not provide any audio data (empty frame). Higher sample rates than 48 kHz are realized by sample multiplexing. When using more than four channels at Double Speed or two channels at Quad Speed, the port labelled AUX has to be used as well.
8. The Sample Rate Converter 8.1 General The ADI-192 DD includes an eight-channel sample rate converter (SRC). Its technical specifications indicate an exceptional conversion quality, formerly known only from synchronous SRC devices. The ADI-192 DD's SRC is asynchronous, yet provides a phase-locked conversion across all eight channels. If the incoming signals are phase-aligned, the SRC converted output signals are as well. Deviations in the sub-sample range are a thing of the past.
In many input formats, the input signal's effective sample rate stays unclear because of possible sample multiplexing. Therefore the frequency range has to be defined manually via the RANGE button: No LED (Single Speed): The effective sample frequency is in the range of 32 kHz up to 48 kHz. DS (Double Speed): The effective sample frequency is in the range of 64 kHz up to 96 kHz. QS (Quad Speed): The effective sample frequency is in the range of 176.4 kHz up to 192 kHz.
TDIF After a HiFS addition to the TDIF-1 specification, and the introduction of Tascam's DA98HR, the TDIF format officially supports up to 192 kHz. Even before that, the Double Wire and Quad Wire methods could be used for the same purpose. In fact Double Wire is identical to the sample multiplexing of HiFS. Apart from the DA98HR, practically no device with TDIF interface supports more than 48 kHz.
9. Word Clock 9.1 Word Clock Input and Output Input The transformer isolated word clock input of the ADI-192 DD is active when WCK has been selected in the CLOCK SECTION. The signal at the BNC input can be Single, Double or Quad Speed, the ADI-192 DD automatically adapts to it. As soon as a valid signal is detected, the WCK LED is lit, else it flashes.
9.2 Technical Description and Background In the analog domain one can connect any device to another device, synchronisation is not necessary. Digital audio is different. It uses a clock, the sample frequency. The signal can only be processed and transmitted when all participating devices share the same clock. If not, the signal will suffer from wrong samples, distortion, crackle sounds and drop outs.
The TDIF format is especially critical with respect to word clock. We have mentioned this in different places of this manual: When the ADI-192 DD is slave no additional word clock connection is necessary. In case DA88 and/or DA38 are slave the word clock output TDIF of the ADI-192 DD has to be connected to the word clock input of the first (master) recorder. When using more than one recorder a special sync cable (Tascam part number PW-88S) is needed. 9.
User's Guide ADI-192 DD Technical Reference User's Guide ADI-192 DD © RME 29
10. Technical Specifications 10.1 Inputs AES/EBU • 4 x XLR, transformer balanced, ground-free, according to AES3-1992 • High-sensitivity input stage (< 0.
10.2 Outputs AES/EBU • 4 x XLR, transformer balanced, ground-free, according to AES3-1992 • Output voltage Professional 4.5 Vpp, Consumer 2.
10.4 Sample Rate Converter • • • • • • • • Self adjusting, high order aliasing filter (-144 dB) Resolution: 24 bit Dynamic Range: 140 dB RMS unweighted, 143 dBA Distortion (THD+N): -140 dB I/O ratio > 1:7 / 7:1 Input / Output sample rate range: 28 kHz - 204 kHz Supports varispeed operation through fast tracking Group delay: 141 samples (3.2 ms @ 44.1 kHz) 10.
10.7 Firmware The ADI-192 DD's main part has been realized using programmable logic. By exchanging a little component called EPROM, both function and behaviour of the unit can be changed at any time. At the time of writing this manual, the unit is shipped with firmware 2.2. The firmware version is displayed after power on by the SYNC and LEVEL LEDs of the INPUT MONITOR for about one second. Firmware 1.1: First firmware for the ADI-192 DD. The current firmware 2.2 includes no bug fixes.
11. Technical Background 11.1 Terminology Single Speed Sample rate range originally used in Digital Audio. Typical applications are 32 kHz (digital radio broadcast), 44.1 kHz (CD), and 48 kHz (DAT). Double Speed Doubles the original sample rate range, in order to achieve higher audio quality and improved audio processing. 64 kHz is practically never used, 88.2 kHz is quite rare in spite of certain advantages. 96 kHz is a common format. Sometimes called Double Fast.
11.2 Lock, SyncCheck and SyncAlign Digital signals consist of a carrier and the data. If a digital signal is applied to an input, the receiver has to synchronize to the carrier clock in order to read the data correctly. To achieve this, the receiver uses a PLL (Phase Locked Loop). As soon as the receiver meets the exact frequency of the incoming signal, it is locked. This Lock state remains even with small changes of the frequency, because the PLL tracks the receiver's frequency.
11.3 DS - Double Speed When activating the Double Speed mode the ADI-192 DD operates at double sample rate. The internal clock 44.1 kHz turns to 88.2 kHz, 48 kHz to 96 kHz. The internal resolution is still 24 bit. Sample rates above 48 kHz were not always taken for granted, and are still not widely used because of the CD format (44.1 kHz) dominating everything. Before 1998 there were no receiver/transmitter circuits available that could receive or transmit more than 48 kHz.
In QS operation, the ADI-192 DD spreads two channel's data on all 8 channels of an ADAT and TDIF port according to the following table: Original DS Signal Port 1 1/2 MAIN 2 5/6 MAIN 3/4 MAIN 7/8 MAIN 3 1/2 AUX 3/4 AUX 4 5/6 AUX 7/8 AUX As the transmission of quad rate signals is done at standard sample rate (Single Speed), the ADAT and TDIF ports still operate at 44.1 kHz or 48 kHz.
11.6 Group Delay – I/O Latency Every digital device has a specific delay time between input and output. The so called group delay of 3 samples for basic applications using the ADI-192 DD is quite low. However, the sample rate converter operates with digital filters, which cause significantly more delay: 141 samples referred to the input sample rate. This equals about 3 ms at 44.1 kHz.
11.7 SteadyClock The SteadyClock technology of the ADI-192 DD guarantees an excellent performance in all clock modes. Its highly efficient jitter suppression refreshes and cleans up any clock signal, and provides it as reference clock at the word clock output. Usually a clock section consists of an analog PLL for external synchronization and several quartz oscillators for internal synchronisation. SteadyClock requires only one quartz, using a frequency not equalling digital audio.
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