Optical Digital Audio Outputs - Benchmark ADC16 Instruction Manual

Optical Digital Audio Outputs

The ADC16 features eight optical digital
outputs. These outputs can be operated in
four different modes: 'S/PDIF', 'ADAT', 'ADAT
2
S/MUX ', and 'ADAT S/MUX
button on the front panel toggles between
'S/PDIF' and 'ADAT' formats. If any ADAT
mode is selected, S/MUX
enabled automatically depending upon the
system sample rate.
In 'S/PDIF' mode, each optical connector
carries two audio channels. Data format is
AES professional. The optical transmitters on
the ADC16 support a maximum sample rate
of 200 kHz in 'S/PDIF' mode . However, most
optical inputs do not support S/PDIF or AES
formats at high sample rates. Check the
specifications on connected equipment before
relying on high sample-rate optical
connections.
In 'ADAT' mode, each optical carries eight
channels of digital audio. In this mode, two
optical connectors are required to carry all 16
channels produced by the ADC16. The
remaining 6 optical connectors provide two
additional sets of outputs. 'ADAT' mode is
only available at sample rates between 28
and 50 kHz. If a higher sample rate is
2
selected, 'S/MUX ' or 'S/MUX
automatically enabled.
2
ADAT 'S/MUX ' is available at sample rates
between 75 and 100 kHz. In this mode, each
optical output carries four channels of audio.
Four connectors are required for 16 channels
of audio. The 8 optical connectors on the
ADC16 carry two identical sets of data when
operating in ADAT 'S/MUX
4
ADAT 'S/MUX ' is available at sample rates
between 150 and 200 kHz. In this mode,
each optical output carries two channels of
digital audio. All 8 optical connectors are
required, to carry 16-channels of audio.
ADC16 Instruction Manual – Rev A
4
'. The 'FORMAT'
2 4
, or S/MUX will be
4
' is
2
'.
The optical outputs use what is often called a
TOSLINK, Type FO5, or 5 mm optical
connector. The ADC16 uses a special high-
bandwidth version that supports AES/EBU
digital audio at sample rates up to 192 kHz.
Please note that many optical inputs cannot
support AES/EBU or SPDIF digital audio at
sample rates above 48 kHz. Some others are
limited to 96 kHz. A few products (such as the
Benchmark DAC1) support 192 kHz optical
inputs. Please note that high-bandwidth
optical transmitters and receivers are not
required for ADAT, ADAT S/MUX
4
ADAT S/MUX .
AES/EBU 'S/PDIF' Optical Mode
 Data Format = AES/EBU professional
 Word Length = 24 bits
 Sample Rates = 28 - 50 kHz, 75 - 100
kHz, and 150 - 200 kHz
 Clock Source = Internal or External
 Data Source = A/D or DAW
ADAT Optical Output Mode
 Data Format = ADAT
 Word Length = 24 bits
 Sample Rates = 28 to 50 kHz
 Clock Source = Internal or External
 Data Source = A/D or DAW
2
ADAT S/MUX
Mode
 Data Format = ADAT
 Word Length = 24 bits
 Sample Rate = 75 to 100 kHz
 Clock Source = Internal or External
 Data Source = A/D or DAW
4
ADAT S/MUX
Mode
 Data Format = ADAT
 Word Length = 24 bits
 Sample Rate = 150 to 200 kHz
 Clock Source = Internal or External
 Data Source = A/D or DAW
2
, or even
Optical Output
Optical Output
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