Allen&Heath M-MADI - Manual (Page 4)

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Q: iLive modular Surfaces can use the RAB2 audio system, this has two slots for options. Which can I use for MADI?
A: Port-A is used for the Surface-MixRack link. The only card supported in current firmware, that can be fitted to surface Port-B is M-MMO.
Typically M-MADI could be used for the iLive Surface to MixRack link and users may want to take advantage of the redundancy mode, where a
second set of cables (send and return) are connected to Link 2.
Q: Can I do recording from an iLive Surface M-MADI?
A: 32 channels in the MADI link are used for the I/O at the surface, plus others are used for PAFL and TB. However, channels 33-62 are freely
configurable in the Port-A tab on the touch-screen OUTPUTS page and Editor software. The M-MADI Aux BNC can be set to ‘repeat’ what is
coming in on Link 1. This way the AUX out can be used for recording at the surface location.
NB If not using redundant mode for a surface link, Link 2 on the surface port-A should not really be connected to anything. Its out port will be
transmitting the signals coming into any input cards fitted to the surface (channels 1-32), and the talkback mic signal (channel 63). Other chan-
nels will be silent. Since the ‘input routing’ in this case is forced to ‘all link 1’, its in port discards any stream connected to it.
Q: Can M-MADI be used with 56 channel systems?
A: The MADI card always transmits 64 channels. It can receive streams containing any number of channels up to 64. If the MADI stream being
provided to the card stops transmitting channels (i.e. it switches from a 64 channel mode to a 56 channel mode without interrupting the stream),
the system will see a constant DC level on these channels, until the cable connected to the ‘IN’ socket is disconnected, or the system is reset.
This is the case with an RME MADI card; switching from 64- to 56-channel mode with audio being received by the A&H MADI card on channels
57-64 will leave a DC level on these signals. Switching from 56- to 64-channel mode works without issue.
Q: Any tips about connecting multiple MADI devices?
A: Daisy chaining A&H MADI devices using ‘T’ connectors so that two or three cards receive the same channels should work when using shorter
cables, but should be discouraged. Users wishing to do this should perform their own experiments to make sure they are happy with the reliabil-
ity of the system. A much better solution is to utilise the AUX BNC, and set its mode to ‘IN1 Through’; this allows 150m runs between devices.
A&H MADI card uses fully differential AC-Coupled inputs. This allows the system to operate with ground differences between connected units,
or, from another perspective, provides better fault tolerance in systems where there is a good common ground. This also means that it is not
possible to form a ground loop with a MADI cable.
Q: Which version of iLive / GLD firmware do I need before using M-MADI?
A: iLive firmware V1.53 or higher, GLD firmware V1.0 or higher. Note that some options are only enabled on GLD firmware V1.1 or higher.
Q: Does M-MADI work with RME and other third party devices?
A: Yes, we have tested M-MADI and it works well with RME devices, however we recommend you update RME devices to the latest version of
firmware. We have customers who have happily used M-MADI with Digico 56-channel MADI streams. M-MADI can provide multi-channel I/O via
SSL or Avid interfaces to ProTools.