Author Topic: USB audio "dummy" feature units  (Read 173 times)

jb

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USB audio "dummy" feature units
« on: August 11, 2017, 11:20:10 am »
This datasheet is pre-Win7 and no longer manufactured, so I'm not sure if this is still relevant:

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The mixing unit MU7 in the headset firmware is a dummy unit and allows the WIN operating system to parse the descriptor correctly. Mac OS does not recognize the recording path if MU7 is present. For that reason it is possible to “short-cut” MU7 with an EEPROM based switch.

Newer version (2008) has a different topology and says:

Quote
The selector unit SU8 in the headset firmware is a dummy unit and allows the Windows operating system to parse the descriptor correctly.

So it seems this modified version works on both Mac and Windows.  Does anyone know what specifically is not recognized, and whether dummy units like this are still required in modern Windows/Mac OS?