User’s Guide HDSP System Digiface
© RME
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10.3 General Operation
The green ‘Lock’ LED (Input State) will light up when the input sees a valid word clock signal.
Selecting ‘Word Clock’ in the ‘Clock Mode’ field will switch clock control over to the word clock
signal. As soon as there is a valid signal at the BNC jack, 'AutoSync Ref' will display 'Word'.
This message has the same function as the green ‘Lock’ LED, but appears on the monitor, i.e.
the user can check immediately whether a valid word clock signal is present and is currently
being used.
The word clock output as well as all ADAT ports only works in Single Speed mode. At 96
kHz, the word clock output will therefore be a 48 kHz signal.
11. Using more than one Hammerfall DSP
The current drivers support multiple interfaces and any combination of I/O-boxes. Please note
that only one ADAT Sync can be used (of course). Additional all systems must be in sync i.e.
have to receive valid sync information (either via wordclock or using AutoSync).
12. Special Characteristics of the SPDIF Output
Apart from the audio data itself, digital signals in SPDIF or AES/EBU format have a header
containing channel status information. False channel status is a common cause of malfunction.
The Hammerfall DSP ignores the received header and creates a totally new one for the output
signal.
Note that in record or monitor modes, set emphasis bits will disappear. Recordings originally
done with emphasis should always be played back with the emphasis bit set!
This can be done by selecting the 'Emphasis' switch in the Settings dialogue ('SPDIF Out'). This
setting is updated immediately, even during playback. The Hammerfall DSP’s new output
header is optimized for largest compatibility with other digital devices:
•
32 kHz, 44.1 kHz, 48 kHz, 88.2 kHz or 96 kHz, depending on the current sample rate
•
Audio use, Non-Audio
•
No Copyright, Copy Permitted
•
Format Consumer or Professional
•
Category General, Generation not indicated
•
2-channel, No Emphasis or 50/15 µs
•
Aux bits Audio Use
Professional AES/EBU equipment can be connected to the Hammerfall DSP thanks to the
transformer-balanced coaxial outputs, and the ‘Professional’ format option with doubled output
voltage. Output cables should have the same pinout as those used for input (see section 8.1
‘Connections’), but with a male XLR plug instead of a female one.
Note that most consumer-orientated equipment (with optical or phono SPDIF inputs) will only
accept signals in ‘Consumer’ format!
The audio bit in the header can be set to 'Non-Audio'. This is necessary when Dolby AC-3
encoded data is sent to external decoders (surround-sound receivers, television sets etc. with
AC-3 digital inputs), as these decoders would otherwise not recognize the data as AC-3.
