Monaural ANALOG_OUT board pair
3.3.5 SYNC_IO board
The SYNC_IO board is an optional clock synchronization board to be used with an external clock generator or together with other
CH products, such as the C1 Digital to Analog Controller. The board provides one clock input and two clock output on BNC
connectors. The VCXO digital PLL of the D1 is capable of frequency and phase locking. The frequency is tracked below 0.1 Hz with
0.1 PPM adjustments for optimal jitter rejection. When fed with an audio Wordclock, the D1's internal clock will always keep a
phase accuracy below 2.5 us (equivalent to sub-millimeter position accuracy), thus enabling phase perfect match in a multichannel
configuration. Following diagram shows the layout of the back panel of the SYNC_IO board:
SYNC_IO board back panel layout
3.3.5.1
BNC clock input
The SYNC_IO board provides a BNC clock input that can be configured as 75 Ohm input impedance or high input impedance
through the D1's menu. Supported input frequencies on this connector are all standard audio Wordclocks (44.1, 48, 88.2, 96,
176.4 and 196 kHz), audio Masterclocks (22.5792 and 24.576 MHz), DSD bitclock (2.8224 MHz) and atomic-clock multiples (100
kHz and 10 MHz). Use this connector to synchronize your D1 unit to an external clock source (atomic clock generator or external
DAC such as CH C1).
3.3.5.2
BNC clock outputs
Two 75 Ohm output clock connectors are also provided on the SYNC_IO board. Use one of these connectors to synchronize an
external device to your D1. Output clock is either a buffered version of input clock (if D1 is synchronized to it input clock), or
Rev 3.0
D1 User Manual
21
