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3. If you’re going to be installing the DA9624 into a situation where its outputs may be
driving an unbalanced input one moment and a balanced input the next, it is worth your
while to get inside the box and rearrange some jumpers. This configures the output stage as
a floating-balanced (cross-coupled) line driver and the balanced outputs behave like an
ungrounded (floating) transformer winding.
The advantage to doing this is that there is no level difference between balanced and unbal-
anced, and the circuit could care less if you ground the cold side to make it unbalanced. If you
do need to operate the DA9624 with its outputs unbalanced, do the unbalancing right at the
rear panel of the DA9624.
The procedure for changing the jumper settings can be found in Section 3 - Fast Setup.
Configuring the output this way reduces the dynamic range by about 1dB.
Digital I/O
The AD9624 has three digital outputs: AES/EBU (XLR-M), TOSLINK (optical), and Coaxial
(RCA). The TOSLINK and Coaxial outputs use the S/PDIF protocol primarily used by con-
sumer equipment. The TOSLINK output is limited to about 30 feet (approx. 10 meters), and
the coaxial output is limited to about 10 feet (approx. 2 meters), depending on the quality of
the coaxial cable.
The AES/EBU output is balanced, and for long cable runs, you may want to use 110-ohm cable
to match the characteristic impedance of the output. (Beldin 1800A as an example. Runs of
several hundred feet are easily accomplished with this cable.)
Note The AD9624 has two front panel switches that select the noise shaping/wordlength for
the two output protocols. There are three different output jacks, and all of them are
active during use. You can use any combination of the outputs simultaneously. Be aware
that the S/PDIF switch affects both the coaxial (RCA) and TOSLINK connections.
The DA9624 has three digital inputs: AES/EBU (XLR-F), TOSLINK (optical) and Coaxial
(RCA). The AES/EBU input is balanced, and the coaxial input is unbalanced. However, both
inputs are transformer-isolated.
Note The DA9624 has a front panel switch that selects the input connection to be used. It is
permissible to have something connected to any of the inputs in any combination.
For More Information
Consult Bob Katz’ website: http://www.digido.com. Bob is a well-known and respected master-
ing engineer and his website has a wealth of information on it. This is worth your time.
Summary of Contents for AD9624
Page 1: ...AD9624 DA9624 24 Bit Converters User s Guide...
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