User manual

Digital Audio Server (DAS) Overview
The Digital Audio Server (DAS) is a true reference designed for the discerning Audiophile. The DAS has an
extremely low noise floor with greater spacial refinement, dynamic accuracy and fine detail retrieval than any
other CD Player or audio server on the market.
The CAAS DAS has been designed to produce the highest audio quality possible. This has been achieved
through our custom bespoke 8 wire digital interface. Featuring 176.4k samples per second up-converting
parallel DACs, data buffering and ultra low jitter clock, allowing near perfect data re-clocking and bit perfect
I
2
S type digital signal transfer.
The DAS is an extremely versatile audio server with two USB inputs, network capability through a LAN
connection and a subsidiary S/PDIF input for direct connection to the DAC ICs.
The DAS is fitted with a Raspberry PI micro computer and a bespoke ultra low jitter re-clocking system that
up-samples digital data to 176.4k samples per second and feeds a parallel arrangement of 16 bit R-2R
DACs. The DAS is fitted with four dedicated discrete regulated power supplies for both Left and Right
analogue channels and seven separate regulated supplies for the digital sections.
The DAS is primarily an Audio Server and the best performance will be achieved when files are accessed
from a USB pen or Hard Disk Drive (HDD). Alternatively digital audio can be streamed from either a NAS, a
PC, a tablet or a smart phone over the LAN connection. A CD transport or other devices can be connected
to the DAS S/PDIF input, however this input bypasses our bespoke low jitter re-clocking system and
therefore is not the primary input.
All music files and data can be accessed through the on screen interface once the DAS has been connected
to a TV or monitor (though HDMI). If the TV has HDMI CEC then all the DAS functions can be accessed
through the TV remote, alternatively the functionality can be accessed through a LAN interface, tablet or
smart phone.
The power supply is a key component in achieving the maximum performance from the audio sections and
for this reason the DAS is fitted with a high specification mains filter and two separate transformers, one for
the analogue sections and one for the digital sections.
The analogue section of the DAS is DC coupling from DAC ICs to the output and has a very short signal
path.
The DAS is fitted with a low power mode that allows the computer to be shut down while the DAC and
S/PDIF input are still operational. This is not a standby mode, it is a reduced power mode for use when the
Audio server is not required and the S/PDIF input is in use.
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