29
For this reason, Mona supports many synchronization modes. Mona can
slave to word clock, S/PDIF, and ADAT. In addition, Mona can also
generate these synchronization signals and Esync, as well as perform
translation of one clock to another, such as transmitting word clock while
reading ADAT.
Let’s take a brief look at the various synchronization types.
Word Clock – This is a synchronization signal that connects to the BNC
connector labeled Word Clock on Mona’s back panel. This synchronization
clock runs at the selected sample rate. Think of it as a kind of electronic
metronome, which clicks back and forth at the digital sample rate. It is one
of the most widely used forms of synchronization in digital audio. Mona is
always generating Word Clock on its Word Clock output BNC connector.
S/PDIF – The Sony/Phillips Digital Interchange Format is a serial bit-
stream that has a clock signal embedded in the data stream. When recording
from an S/PDIF source, whether via optical or RCA cables, Mona will
utilize the synchronization clock that is embedded in the S/PDIF while it
decodes the bitstream.
Note: When recording from a S/PDIF port, you must select S/PDIF as the
input clock. For greater flexibility, this is not done automatically. If you
find that your S/PDIF recordings contain pops or skips, be sure that you
have selected S/PDIF as your input clock.
ADAT – The Alesis ADAT optical interface can send and receive up to 8
simultaneous channels of digital audio data over fiber optic cables. Unlike
wire cables, fiber optic cables do not add noise or interference. To check if
the optical cable is carrying a signal, just look at the end for a glowing red
light. Mona can send out (or “master”) ADAT clock as well slave to it. If
you want Mona to slave to an ADAT clock, just set Mona’s input clock to
the ADAT setting.
Note: To preserve the high audio quality of Mona’s converters it is best to
use Mona’s Internal input clock setting instead of synchronizing to an
external ADAT clock, which may add unwanted jitter to the signal.