RME HDSPe MADI [35/72] Word clock

User's Guide HDSPe MADI © RME

23.3 MIDI

The HDSPe MADI offers two MIDI I/O via 5-pin DIN connectors. The MIDI ports are added to

the system by the driver. Using MIDI capable software, these ports can be accessed under the

name MADI MIDI. Using more than one HDSPe MADI, a consecutive number is added to the

port name, like MADI MIDI In 1 (2) etc.

The third software-only MIDI port, MADI MIDI In 3 (1) and MADI MIDI Out 3 (1), receives and

transmits MIDI data via MADI. This allows for a direct communication between systems with

HDSPe MADI cards. Additionally MIDI data can be transmitted from/to other RME devices with

MADI ports, and both can be MIDI remote controlled without any additional line or cabling be-

tween computer (MADI card) and unit.

24. Word Clock

24.1 Word Clock Input and Output

SteadyClock guarantees an excellent performance in all clock modes. Based on the highly effi-

cient jitter suppression, the HDSPe MADI refreshes and cleans up any clock signal, and pro-

vides it as reference clock at the BNC output (see chapter 30.6).

Input

The HDSPe MADI's word clock input is active when Pref. Sync Ref in the Settings dialog has

been switched to Word Clock, the clock mode AutoSync has been activated, and a valid word

clock signal is present. The signal at the BNC input can be Single, Double or Quad Speed, the

HDSPe MADI automatically adapts to it. As soon as a valid signal is detected, the green LED is

lit, and the Settings dialog shows either Lock or Sync (see chapter 30.2).

Thanks to RME's Signal Adaptation Circuit, the word clock input still works correctly even with

heavily mis-shaped, dc-prone, too small or overshoot-prone signals. Thanks to automatic signal

centering, 300 mV (0.3V) input level is sufficient in principle. An additional hysteresis reduces

sensitivity to 1.0 V, so that over- and undershoots and high frequency disturbances don't cause

a wrong trigger.

The word clock input is shipped as high impedance type (not terminated). A push switch allows

to activate internal termination (75 Ohms). The switch is found beside the word clock input

socket. Use a small pencil or similar and carefully push the blue switch so that it snaps into its

lock position. The yellow LED will be lit when termination is active. Another push will release it

again and de-activate the termination.

Output

The word clock output of the HDSPe MADI is constantly active, providing the current sample

frequency as word clock signal. As a result, in Master mode the provided word clock is defined

by the currently used software or the DDS dialog. In Slave mode the provided frequency is iden-

tical to the one present at the currently chosen clock input. When the current clock signal fails,

the HDSPe MADI switches to Master mode and adjusts itself to the next, best matching fre-

quency (44.1 kHz, 48 kHz etc.).

Selecting 96 kHz – 48K Frame in the Settings dialog causes the output signal to always stay

within the range of 32 kHz to 48 kHz. So at 96 kHz sample rate, the output word clock is 48

kHz.