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User's Guide ADI-192 DD   © RME

23

 

8. The Sample Rate Converter 

 

8.1 General 

 
The ADI-192 DD includes an eight-channel sample rate converter (SRC). Its technical specifica-
tions 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. 
 
A SRC allows a conversion of the sample rate in real-time. The 24 bit converters used in the 
ADI-192 DD operate practically without loss of signal quality, so no audible artefacts or noise is 
added. In fact, the SRC works so well that we could recommend to just leave it on at all times, 
thus eliminating all clock problems right from the start. 
 
The ADI-192 DD offers a maximum conversion rate of 1:7 or 7:1, respectively. Thus, 192 kHz 
can be converted to any sample rate down to 32 kHz, and 32 kHz can be converted to any fre-
quency up to 192 kHz. 
 
When using the internal clock, every SRC also works as a jitter killer. However, the ADI-192 DD 
is equipped with SteadyClock, thus operating as perfect jitter killer with any clock source. 
 
An SRC not only converts sample rates, it also serves as a clock decoupler. With SRC active, 
even non-synchronizable devices (CD-players, DAT machines, etc.) can be used in a setup of 
digital devices, just as if they were externally synchronized. The SRC decouples input and out-
put clock, sets the output clock to the common reference, thus allowing the combination of dif-
ferent clock-sources without any clicks or dropouts. 
 
 

8.2 Operation

 

 
The button SRC INPUT SOURCE defines the data path in which the sample rate converter will 
be inserted: AES, TDIF or ADAT. With no LED lit, the SRC is deactivated. Selecting the same 
input in the OUTPUT section as in the SRC INPUT SOURCE section, the LED SRC indicates 
an activated sample rate conversion. Selecting the function SRC in the OUTPUT sections is not 
necessary. 
 

 

Содержание ADI-192 DD

Страница 1: ...SyncAlign SyncCheck Intelligent Clock Control Hi Precision 24 Bit 192 kHz 8 Channel Triple Universal Format Converter 8 Channel Sample Rate Converter ADAT optical TDIF AES EBU Interface SteadyClock T...

Страница 2: ...2 TDIF 21 7 3 ADAT Optical 22 8 The Sample Rate Converter 8 1 General 23 8 2 Operation 23 8 3 Clock Decoupling using the SRC 25 8 4 The SRC as Signal Conditioner 25 9 Word Clock 9 1 Word Clock Input a...

Страница 3: ...ture and water from entering the device Never leave a pot with liquid on top of the device Do not use this product near water i e swimming pool bathtub or wet basement Danger of condensation inside do...

Страница 4: ...4 User s Guide ADI 192 DD RME...

Страница 5: ...User s Guide ADI 192 DD RME 5 User s Guide ADI 192 DD General...

Страница 6: ...th chapter 11 1 Terminology 2 Package Contents Please check that your ADI 192 DD package contains each of the following ADI 192 DD User s Guide Power chord 3 Brief Description and Characteristics The...

Страница 7: ...I O port via TOSLINK cable The rear of the ADI 192 DD provides all the connections eight AES EBU XLR four ADAT optical TOSLINK two TDIF D sub 25 three word clock BNC and mains power ADAT I O MAIN TOS...

Страница 8: ...ined in the CLOCK SECTION The button CLOCK steps through the choices external clock AES TDIF ADAT and word and in ternal clock 44 1 or 48 kHz The button STATE defines the sample rate range for both in...

Страница 9: ...and ADAT at the same time just an example Any combination that one can imagine is allowed The big block diagram also printed on the unit s cover see chapter 12 shows further details like the AES inpu...

Страница 10: ...f business drawn up by Audio AG apply at all times 6 Appendix RME news and further information can be found on our website http www rme audio com Distributor Audio AG Am Pfanderling 60 D 85778 Haimhau...

Страница 11: ...ser is encouraged to try to correct the interference by one or more of the following measures Reorient or relocate the receiving antenna Increase the separation between the equipment and receiver Conn...

Страница 12: ...12 User s Guide ADI 192 DD RME...

Страница 13: ...User s Guide ADI 192 DD RME 13 User s Guide ADI 192 DD Usage and Operation...

Страница 14: ...ing will let the DW Double Wire LED light up Unfortunately this information is insufficiently standardised and is even set falsely from several devices Therefore the DW LED is just a user information...

Страница 15: ...ces is synchronous to the ADI 192 DD Therefore the external device has to be syn chronized to the ADI 192 DD s word clock out or AES TDIF ADAT out The ADI 192 DD thus has to be master all devices conn...

Страница 16: ...Hz 1 channel per AES wire The effective sample frequency is double the clock of the AES wire QW Quad Wire 2 channels 176 4 192 kHz 1 channel via 2 AES wires The effective sample frequency is four time...

Страница 17: ...n but also with SRC activated The ADI 192 DD supports all currently known formats in the range of 32 kHz up to 192 kHz including sample multiplexing Single Wire 8 channels 32 kHz 192 kHz 2 channels pe...

Страница 18: ...a b 3a b 4a b 5a b 6a b 7a b 8a b With input signals in the Quad Speed range the SRC RANGE or the Clock Section STATE have to be switched into QS mode manually depending on the current application Eac...

Страница 19: ...UX Additional port for receiving channels 5 to 8 in S MUX or 3 and 4 in S MUX4 mode With input signals encoded as S MUX the SRC RANGE or the Clock Section STATE have to be switched into DS mode manual...

Страница 20: ...in a channel status coding which is being used for transmitting further information The output signal coding of the ADI 192 DD has been implemented according to AES3 1992 Amendment 4 32 kHz 44 1 kHz 4...

Страница 21: ...ons SW DW and QW are available The distribution of the samples performed in the Double Wire mode equals the S MUX method and is done as follows Channel Port L 1 R 1 L 2 R 2 L 3 R 3 L 4 R 4 Samples 1a...

Страница 22: ...al MAIN carries the channels 1 to 4 in case of S MUX4 MAIN carries channels 1 and 2 ADAT AUX Additional port for a transmission of channels 5 to 8 in S MUX or 3 and 4 in S MUX4 mode When operating in...

Страница 23: ...spectively Thus 192 kHz can be converted to any sample rate down to 32 kHz and 32 kHz can be converted to any fre quency up to 192 kHz When using the internal clock every SRC also works as a jitter ki...

Страница 24: ...ll light up automatically and can t be deselected At 96 kHz only DS and QS can be selected since the audio signal can t be 48 kHz At 48 kHz however the device can not determine whether the signal is 4...

Страница 25: ...ng synchronization Clicks and drop outs are the consequence Normally the mixing console works as master and delivers a reference signal word clock to all other devices But this is only possible if the...

Страница 26: ...s constantly active providing the current sample frequency as word clock signal In master mode the word clock will be fixed to 44 1 kHz or 48 kHz DS x 2 QS x 4 In any other case the sample rate is ide...

Страница 27: ...by 256 inside the device using a spe cial PLL to about 11 2 MHz This signal then replaces the one from the quartz crystal Big dis advantage because of the high multiplication factor the reconstructed...

Страница 28: ...Ohms you have to take into account that a device of which the input only works from 2 8 Volts and above does not function correctly al ready after 3 meter cable length So it is not astonishing that be...

Страница 29: ...User s Guide ADI 192 DD RME 29 User s Guide ADI 192 DD Technical Reference...

Страница 30: ...4 2 x 8 channels 24 bit 48 kHz equalling 4 channels 24 bit 192 kHz Bitclock PLL ensures perfect synchronisation even in varispeed operation Lock range 28 kHz 54 kHz Jitter when synced to input signal...

Страница 31: ...s 24 bit 48 kHz equalling 8 channels 24 bit 96 kHz S MUX4 2 x 8 channels 24 bit 48 kHz equalling 4 channels 24 bit 192 kHz TDIF 2 x D sub 25 pin according to TDIF 1 Standard 8 channels 24 bit up to 48...

Страница 32: ...7 2 x 1 73 x 9 3 Weight 2 kg 4 4 lbs Temperature range 5 up to 50 Celsius 41 F up to 122 F Relative humidity 75 non condensing 10 6 Connector Pinouts D Sub TDIF 1 The 25 pin D sub connectors are wired...

Страница 33: ...nd ing LED in the OUTPUT section flashes in the same way as the ones in the SRC and CLOCK SECTION This change unifies the user interface of the ADI 192 DD and improves overview because invalid inputs...

Страница 34: ...requires two AES EBU ports See chapter 11 3 The Double Wire method is an industry standard today however it has a number of different names like Dual AES Double Wide Dual Line and Wide Wire The AES3 s...

Страница 35: ...from internal clock to AES its internal clock will then be the clock delivered by the CD Player But in case a DAT recorder is connected as a second source there will again be a slight difference in th...

Страница 36: ...g digital tape recorders But also other and newer interfaces like ADAT or TDIF are still using this technique And finally it can be used to transfer 192 kHz using 96 kHz capable equipment Since the AD...

Страница 37: ...ce is described by IEC 60958 Type AES3 1992 IEC 60958 Connection XLR RCA Optical Mode Balanced Un balanced Impedance 110 Ohm 75 Ohm Level 0 2 V up to 5 Vss 0 2 V up to 0 5 Vss Clock accuracy not speci...

Страница 38: ...to AES 5 AES to ADAT ADAT to AES 6 TDIF to TDIF 2 ADAT to ADAT 3 ADAT to TDIF TDIF to ADAT 5 ADAT to TDIF TDIF to AES AES to ADAT 8 AES to AES with SRC 144 Double Speed AES to AES 5 AES to TDIF TDIF t...

Страница 39: ...z SteadyClock has originally been de veloped to gain a stable and clean clock from the heavily jittery MADI data signal The embedded MADI clock suffers from about 80 ns jitter caused by the time resol...

Страница 40: ...40 User s Guide ADI 192 DD RME 12 Block Diagram...

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