Manual CC2 © Grimm Audio
9
5. Operation
The CC2 is a high performance master clock, it has no
slave option. Switches on the front and back offer
adjustments to the needs of your system and project.
On the front
•
The bottom (horizontal) toggle switch selects a 44.1
or 48 kHz base rate.
•
The top (vertical) toggle switch has three positions
and sets the multiplication factor of the base rate to
1, 2 or 4.
These switches control both BNC outputs
simultaneously. LEDs on the front indicate the current
sample rate setting.
On the back
Two miiniature switches select between 75 Ohm or Low
output impedance per BNC output.
Output impedance
Word sync connections are usually 5V square waves
transmitted using 75 ohm (video) coax cables. Although
the word clock frequency itself is relatively low, the
transitions are steep. Taken as a whole, word sync is a
wideband signal, usually necessitating characteristic
termination at least at one end of the cable. Better still
is series termination on the transmit end and parallel
termination on the receiving end. This minimises
reflections even when the cable impedance is not
exactly matched.
Double termination like this produces a 6dB loss,
resulting in an effective 2.7V signal. All Grimm Audio
products are designed to work in this manner.
Unfortunately there is no standard defined for word
sync connections. As a result, implementations vary
across various makes. Outputs may be series
terminated or low impedance, DC or AC coupled. Inputs
may be parallel terminated or high impedance. This
yields to 8 permutations, all of them encountered in the
field. To make things worse, we have reports from
5.
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