User manual RME ADI8DS

[. . . ] User's Guide SyncAlign ® ® TM SyncCheck Intelligent Clock Control Hi-Precision 24 Bit / 96 kHz 8 Channel AD / DA-Converter ADAT® optical / TDIF®-1 Interface Digital 24 Bit Interface / Format Converter TDIF-1 24 Bit Interface 2 User's Guide ADI-8 DS © RME Contents 1 2 3 4 Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Supplied Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Brief Description and Characteristics . . . . . . . . . . . . . . . . . . . 4 Technical Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . [. . . ] D/A The same options are available for the DA-converter. The key DIGITAL INPUT determines the digital input being used, and the clock source in case INPUT was activated before. As not all combinations of clock settings make sense some of them are blocked. The limitations mainly affect TDIF operation and the setting Clock INTERNAL DA. Please note that the DA key has priority. In case an allowed combination can't be set simply press the D/A key, set A/D as desired, and set D/A back to its last state. The Lock state of the ADI-8 DS is indicated by a blinking (error) or constantly lit (Ok) EXT. or INPUT LED in the Clock section. Clock mode D/A Internal Clocking the DA-converter from the internal quartz crystal is propably the most outstanding feature of the ADI-8 DS. This technique provides simply the best sound quality, as the internal clock has very low jitter, so that the DA-converters can achieve the highest signal to noise ratio and lowest distortion. The setting Clock D/A INTERNAL requires a synchronous operation of all devices. To guarantee this the external device connected to the ADI-8 DS has to synchronize itself to the clock from the word clock output or ADAT/TDIF output of the ADI-8 DS. The ADI-8 DS has to be master, all attached devices slave. To prevent a not better but worse sound quality caused by imperfect or even no synchronisation, a special method called SyncCheck compares the synchronisity of the incoming data with the internal clock of the ADI-8 DS. The actual state is indicated by a blinking (error) or constantly lit (Ok) ADAT or TDIF LED in the DIGITAL INPUT section. In clock mode D/A INTERNAL the clock choices EXTERNAL and INPUT of the AD-section do not make sense, as the clock at the digital output has to be synchronous to the internal clock. Therefore A/D INTERNAL is automatically activated and cannot be changed. 12 User's Guide ADI-8 DS © RME 8. Word Clock 8. 1 Operation and Technical Background In the analogue domain one can connect any device to another device, a synchronization is not necessary. Correct interpretation of digital audio data is dependent upon a definite sample frequency. Signals can only be correctly processed or transferred between devices if these all share the same clock. Otherwise digital signals are misinterpreted, causing distortion, clicks/crackle and even dropouts. AES/EBU, SPDIF and ADAT optical are self-clocking (seen from a non-technical view TDIF too, as word clock is embedded inside the TDIF cable), so an additional line for word clock could be considered redundant. In practice however, using several devices at the same time can cause problems. [. . . ] The copy of the sales receipt or the Bill of Sale is your warranty legitimation. In case of any error or defect please contact your local dealer. The warranty does not cover damage due to abuse, incorrect installation or incorrect handling. RME's liability is limited to the repair or the replacement of the product, and does in no way include the liability for incidental or consequential damages resulting from using the ADI-8 DS. 14. [. . . ]