16
Operation
An optical S/P-DIF digital audio signal is re-clocked. All outputs
provide their signals on the same clock rate like this one of the
incoming optical S/P-DIF digital audio signal.
An AES3 signal is externally-referenced and re-clocked with an
additional Word Clock signal. All outputs provide their signals
with same clock rate like this one of the incoming AES3 digital
audio signal, except the Word Clock output 3 is set to output the
double clock rate of the reference signal.
Selecting Clock Multipliers
Pressing the »MENU« key changes from the »REFERENCE» to the »CLOCK MULTIPLIERS« menu. Here you can select for
every pair of Word Clock and the digital audio outputs individual clock rate multiplication factors of
×
1,
×
2,
×
4 and
×
256 by
pressing the »SELECT« key repeatedly. The multiplication factors refer always to the basis clock rate of the incoming reference
signal or the clock rate selected of the internal ultra-low-jitter clock generator (»IN 10.0M«). Thus, dependently of
the incoming or selected basis clock rate, the MC-3+ covers a range of audio related clock rates from 32.0 kHz up to 768.0 kHz
plus the two so-called Super Clocks.
The setting »
×
256«, or so-called Super Clock, is only available for the three pairs of Word Clock outputs. It transmits either a
clock rate of 11,289.6 MHz (44.1 kHz
×
256) or 12,288.0 MHz (48.0 kHz
×
256). The system analysis in any way the basis clock
rate of the incoming or the generated reference clock signal, 44.1 kHz or 48.0 kHz, and outputs the corresponding Word Clock
×
256 for use with older digidesign ProTools
TM
systems.
The multiplication of the digital audio outputs S/P-DIF (»4«) and AES3/11 (»5«) is limited to a maximum clock rate of
192.0kHz, regardless of the clock rate of the reference signal.
Attention
Multiplying Digital Audio Signals – When having a digital audio input selected as reference and setting the multiplication
factor to higher than »
×
1«, the MC-3+ outputs a blank frame signal only at the audio outputs. A sampling rate conversion of
the incoming digital audio signal is not carried out.
Status Information
The »STATUS« and »CLOCK
IN
« menus are for control of the MC-3+‘s operation status only. They are not accessable for adjust-
ments with help of the keys.
STATUS
»LOCK«
This blue LED lights when the internal PLL circuit has detected the incoming clock reference signal as valid. If the reference
signal is unstable or lost, the »LOCK« LED does not light.
MODE
RE-CLOCK
EXTERNAL
INTERNAL
x 256
x 4
x 2
x 1
CLOCK
MULTIPLIERS
1
5
4
3
2
REFERENCE
S/P-DIF op
S/P-DIF co
88.2
48.0
44.1
32.0
192.0
96.0
176.4
10.0M
WCLK
IN 10.0M
AES3/11
MODE
RE-CLOCK
EXTERNAL
INTERNAL
x 256
x 4
x 2
x 1
CLOCK
MULTIPLIERS
1
5
4
3
2
REFERENCE
S/P-DIF op
S/P-DIF co
88.2
48.0
44.1
32.0
192.0
96.0
176.4
10.0M
WCLK
IN 10.0M
AES3/11
