Manual

User's Guide MADI Converter © RME

7.2 MADI Converter Technology

A MADI patchbay basically can be realized in two ways: using a complete signal regeneration

(including reclocking), or by a buffered distribution of the un-processed input signal.

Complete Signal Regeneration: This method requires a complete MADI receiver per input,

and a complete MADI transmitter per output. The signal must be processed and reclocked. The

costs are extreme, as the special MADI chip (required 8 times!) is already very expensive. Addi-

tionally another very powerful FPGA is necessary. Operation gets cumbersome, as the unit has

to provide full clock support and control. The advantage is that the MADI signal at the output is

completely independent from the quality of the input signal, as it is fully newly generated.

Buffered Distribution: This method uses a sensitive receiver to amplify the input signal to a

standard level, then sends out this signal by an active driver stage. The signal is not processed

nor reclocked. The different combinations (routings) of the input and output signals as well as

the MIDI control can be performed by a fast FPGA. The component costs are dramatically lower

compared to the Signal Regeneration method. The operation is very easy, as the current clock

situation is completely ignored. The disadvantage is that the quality of the output signal de-

pends on that of the input signal, as the signal is passed on nearly unchanged. Additionally the

maximum coaxial cable length is reduced, as a signal to/from the MADI Converter travels dou-

ble the distance.

RME's MADI Converter uses adapted termination and a special equalizing, to reach higher

cable lengths despite its simpler design. The MADI Converter can even serve as cable buffer

for the limited outputs of some manufacturers (90 meter coaxial instead of 30 meter...).

Real world tests with MADI devices of various manufacturers confirmed the outstanding per-

formance of the MADI Converter. There exists only one exception: The output signal of the

Sony 3348 (digital tape machine of the first MADI generation) becomes unreadable when

passed through the MADI Converter. This problem can be addressed by the MADI Bridge,

which offers a special 3384 compatibility mode (see manual).