4
MCDA
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112
Manual
AIR TEMPERATURE AND HUMIDITY
Normal operation of this unit is warranted under ambient conditions defined by EN 60721-3-3, set IE32,
value 3K3. The most important conditions of this standard are ambient tempe5 to +40°C, relative
humidity 5% to 85% (with no ice or condensation), absolute humidity 1 to 25 g/m3 and rate of temperature
change <0.5°C per minute. Care should be taken to avoid operation outside these limits or erratic operation
may result.
DESCRIPTION
The ATI Model MCDA-112 can function as an ultra-low jitter studio master clock or as a 1X12 clock
distribution amplifier. When used as a studio master clock, the MCDA can generate an exceptionally stable
44.1, 48, 88.2, 96, 176.4 or 192 kHz clock reference for the purpose of synchronizing all of your connected
digital equipment. This single clock source assures a trouble-free digital workflow throughout you digital
studio or facility. The output clock format can be either Word Clock or Super Word Clock, and this signal is
available on all 12 of the MCDA’s individually isolated outputs.
If you prefer to use another source for your reference clock, the MCDA-112 can function as a 1X12 clock
distribution amplifier. It can accept an AES3 audio signal, an AES Word Clock, or a Super Word Clock as an
input, and will output either Word Clock or Super Word Clock from its 12 BNC output connectors.
Since the purity of the clock reference is critical to the quality of the finished audio product, ATI has taken
steps to assure that the MCDA-112 generates the lowest jitter clock reference available. The MCDA-112’s
internal reference is derived from a 24 MHz precision oscillator and divided down to achieve an ultra-stable
signal, rather than multiplying up from a base reference as in other units.
The MCDA-112 has both Input and Loop-thru outputs to allow downstream equipment to be fed from the
input signal. When no downstream equipment is connected, the inputs should be terminated via the front
panel Input Termination switch.
When fed from an external reference signal, the MCDA-112 will indicate the clock frequency of the input
signal from 32 through 192 kHz.
A front panel lock switch protects all settings. The MCDA-112 retains all of its settings, even if power is
removed.
INPUTS
Incoming AES/EBU formatted digital audio data, AES11, word clock or super word clock is applied to
individual input transformers. Input termination resistors at 75 ohms for BNC inputs or 110 ohms for
XLR inputs can be switched in or out of the circuit with the front panel Input Term switch. Inputs should
always be terminated unless they are looped thru to another device or a second MCDA input. The last
device or input should always terminate the line.
OUTPUTS
All outputs, numbered 1 through 12, are live at all times. Outputs contain either Word Clock or Super
Word Clock and do not contain AES audio. (For AES audio Distribution Amplifiers, see our Models
DDA-106BNC, DDA-106XLR, DDA-212BNC and DDA-212XLR.)
It is not necessary to terminate unused outputs, as each is individually isolated. Cable routing should
be kept clear of AC lines and other noise-producing wiring, especially when working at Super Word
clock rates.
