Alesis Hammerfall DSP System manual Connections, Headphones, Madi I/Os

22. Connections

22.1 Headphones

HDSP MADI offers a hi-quality analog monitor output. The short circuit protected stereo line output provides high output level, low impedance, and is available via a 6.3 mm (1/4") TRS jack. Therefore it is also suitable for a direct use with headphones.

The analog output is directly driven from the channels 63/64, in Double Speed mode with chan- nels 33/34. Its output volume is controlled by the hardware output faders of channel 63/64 in TotalMix. Additionally the analog output can play back any input or playback signal (submix, for example factory preset 5, 6 and 7).

RME's unique Speaker Protection re- duces noise when switching the com- puter on and off, so there is no problem even when using active monitors.

In case the output should operate as line out, an adapter TRS plug to RCA phono plugs, or TRS plug to TS plugs is re- quired.

The pin assignment follows international standards. The left channel is connected to the tip, the right channel to the ring of the TRS jack/plug.

22.2 MADI I/Os

The BNC input's ground-free design is built according to AES10-1991. The input impedance is 75 Ohm. It will operate error-free from about 180 mVpp on.

The optical input and output uses a FDDI (ISO/IEC 9413-3) compatible optical module, accord- ing to AES10-1991. More information can be found in chapter 30.1, MADI Basics.

HDSP MADI includes automatic input selection (Safe Mode Input). In case the current input signal fails, the unit switches to the other input immediately. This mode, called redundancy mode, offers improved safety against errors on the transmission line. Switching the inputs is done in about one second. Redundancy operation is displayed in the Settings dialog.

The BNC output is built according to AES10-1991. The output's impedance is 75 Ohm. The output voltage will be 600 mVpp when terminated with 75 Ohm. Changing the internal blue jumper X4 to the upper position, the output voltage is increased to 1.2 Vpp. This setting is not intended to be used in normal operation. But in case of a very long or 'lossy' coaxial cable, this setting may ensure an error-free operation of the transmission line.

38 User's Guide HDSP MADI © RME