Instruction manual

DAC1 HDR Instruction Manual Rev I Page 15
The DAC1 USB is designed, tested and
proven compatible with Windows
Vista/XP/2000 and Mac OS X with no driver
installation or system configuration required.
For the up-to-date information about more
recent operating systems and suggestions for
optimization, go to:
www.benchmarkmedia.com/wiki.
TIP – Visit our computer audio
application pages for the latest
information on media players, media
servers, operating systems, and audio-
related computer accessories:
www.benchmarkmedia.com/wiki
These pages include instructions for
maximizing the performance of media
servers.
Digital Input 1 – Optical
The optical input connector is commonly
known as a TOSLINK connector. The TOSLINK
optical connector used on the DAC1 HDR is
designed to work well at sample rates up to
96 kHz. Maximum word length is 24-bits. All
sample rates between 28 and 96 kHz are
supported. The optical input will accept
professional AES/EBU data formats or
consumer S/PDIF data formats.
Digital Inputs 2, 3, and 4 -
Coaxial
The coaxial inputs use female RCA connectors
that are securely mounted directly to the rear
panel. The input impedance is 75 Ohms.
Maximum word length is 24-bits. All sample
rates between 28 and 195 kHz are supported.
The Coax inputs are DC isolated, transformer
coupled, current limited, and diode protected.
The RCA body is bonded directly to the
chassis to prevent currents in the internal
ground systems. This direct bonding also
maximizes RF shielding.
TIP: Shielded 75-Ohm coaxial cable is
required for stable performance. Do not
use 50-Ohm cables or twisted pair
cables, or any non-coaxial cables.
The Coaxial inputs accept AES/EBU or S/PDIF
digital audio formats. AES3-id and SMPTE
276M standards specify 75-Ohm 1 Vpp
professional format digital audio signals and
these are commonly used in video production
facilities. IEC 609588-3 specifies 75-Ohm 0.5
Vpp consumer-format digital audio signals
(commonly known as S/PDIF). The coaxial
inputs on the DAC1 HDR are designed to
accept either type of signal.
Analog Outputs
The DAC1 HDR has two unbalanced RCA
outputs and two balanced XLR outputs.
The DAC1 HDR features new high-current
output drivers that are capable of driving
300-Ohm loads without an increase in
distortion. They are also well suited for
driving long cables or high-capacitance loads.
Note: The XLR and RCA output levels are
controlled by the Volume Control level when
the Output Level Switch is set to variable.
The levels are set by the 10-turn calibration
trimmers located internally on the circuit
board, when the Output Level Switch is set
to Calibrated. The XLR and RCA outputs are
muted, when the switch is in the center
position.
The XLR outputs are equipped with low-
impedance passive output attenuators that
can be set at 0 dB, -10 dB, -20 dB, or -30 dB
to allow interfacing to a wide variety of audio
devices without any loss of dynamic range. A
full description of the output attenuators and
instructions for configuration is located in the
Internal Setting section of this manual.