User's Manual

T-0000-0005-V2.1: Digital Mozart II Module
T-0000-0005-V2.1: Digital Mozart II Module Page: 2 / 4
4 Other Peripherals
4.1 S/PDIF
The optical and coaxial outputs for S/PDIF are driven by a Cirrus Logic CS8406 S/PDIF encoder.
Software re-sampling is used for non-native frequencies. The Quartet II reference schematic includes
this part configured to drive an optical transmitter. To support coaxial SPDIF output, please contact
AwoX for more information.
4.2 FM TUNER
The reference tuner for use with Mozart II Digital is the Silicon Labs Si4704. The tuner has analog
outputs, which means that its use on a daughterboard requires proper analog signal handling. The
part is the same that is used on the analog variant of Mozart.
5 Daughterboard Schematic Description
Front Panel, iPod , and Rear Panel Interface are identical to the digital version (with the exception of
the Line Out replaced by Line In for demonstration purposes, but this input is directly managed by the
amplifier used).
Therefore, the description only highlights the Main Board which is quite simple.
5.1 AUDIO AMP SECTION (PAGE 1)
The amplifier U4 and the module use external I2S clocking, providing the main frequency from crystal
Y2.
5.2 FM TUNER & INTERCONNECT (PAGE 2)
The FM tuner requires the use of a band-pass filter for proper FM reception. It uses its own external
clock (Y3). Note that the interrupt line to the processor is shared and therefore open-drain, J20 is the
connection to interface board.
5.3 5.3 POWER & CONNECTORS (PAGE 3)
Strictly identical to analog version.