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DUA II User Manual
© 2000 Merging Technologies
When using the DUA II as a stand-alone unit, how do you route audio through the unit?
Can you do it without patching the ADAT INs and OUTs together?
When using the DUA II as a stand-alone unit, the DIP Switch 7 should be set to enable the STAND ALONE mode.
This way all inputs are routed internally one-to-one to the outputs. There is no need for an ADAT external loop.
In a manner to use the DUA II as a stand alone 4 CH A/D and 4 CH D/A converter, you will also need to set DIP
Switch 5 and clear the DIP Switch 6. With this configuration, DUA II routes signals as follow:
- Analog line signals on inputs 1 and 2 are converted to a digital AES/EBU signal on output 5/6,
- Analog line signals on inputs 3 and 4 are converted to a digital AES/EBU signal on output 7/8,
- Digital AES/EBU signal on input 5/6 is converted to two analog line signals on outputs 1 and 2,
- Digital AES/EBU signal on input 7/8 is converted to two analog line signals on outputs 3 and 4,
What i
s
the best setup (again, stand-alone-no computer) for measuring and testing the audio coming out AES
and Analog?
The configuration described above should be a pretty good example of how to setup DUA II for a stand-alone A/D
and D/A quality measurement. This setup allows both a A/D path and a D/A path to be measured, using for example
an Audio Precision equipment which can generate test tones in AES/EBU format, while analyzing the returned
analog line signals or the opposite as well (generating analog line signals and analyzing returned digital AES/EBU
signals)
I want to place the DUA II in a machine room, what is the maximum cable length I can use for the Optical
cables?
When using Mykerinos and the DUA II for example, we have tested optical runs of up to 10 meters, using standard
APF (All Plastic Fiber) cables without problems. The official maximum length recommended by Alesis (the makers
of ADAT) is 6 meters.
Beyond 10 meters (and up to 1000 meters), the setup requires the addition of two Merging
Onouris
LDS (Long
Distance System) converters.
Contact Merging if you would like to run optical cables longer than 10 meters.
Can you solve the optical cable distance by simply substituting glass optical cables for the plastic cables?
This is not a recommended practice. If you need length, only switching to glass optical cable is not enough.
You will need to change the optical ‘driver’ and ‘receiver’ as well.
Merging provides the whole system, composed of two glass optical cables and one
Onouris
LDS at each end.
This system allows a bi-directional link of up to 1000 meters.
Appendix 5 – Glossary of Terms
Here are some common audio terms used in this document.
ADAT
This is a multichannel optical digital interface. It is a proprietary standard, which is used in the family of Alesis
ADAT digital multitrack recorders. The ADAT data stream contains 8-channels of digital audio data through a single
fiber optic cable. ADAT is a registered trademark, property of Alesis Corp.
AES/EBU
AES/EBU is a serial transmission format standardized for professional digital audio signals A specification using
time division multiplex for data, and balanced line drivers to transmit two channels of digital audio data on a single
twisted-pair cable using 3-pin (XLR) connectors.
WCLK
WCLK (or Word-Clock) is a TTL-compatible square wave signal at a specific sample rate such as 48 kHz.