Omega Speaker Systems PCI-DAS1002 PCI-DAS1000 and signal source already have isolated grounds

Relying on the earth prong of a 120VAC for signal ground connections is not advised.. Different ground plugs may have large and potentially even dangerous voltage differentials. Remember that the ground pins on 120VAC outlets on different sides of the room may only be connected in the basement. This leaves the possibility that the “ground” pins may have a significant voltage differential (especially if the two 120 VAC outlets happen to be on different phases!)

PCI-DAS1000 and signal source already have isolated grounds

Some signal sources will already be electrically isolated from the PCI-DAS1000. The diagram below shows a typical isolated ground system. These signal sources are often battery powered, or are fairly expensive pieces of equipment (since isolation is not an inexpensive proposition), isolated ground systems provide excellent performance, but require some extra effort during connections to assure optimum performance is obtained. Please refer to the following sections for further details.

4.2 WIRING CONFIGURATIONS

Combining all the grounding and input type possibilities provides us with the following potential connection configurations. The combinations along with our recommendations on usage are shown in the chart below.

Ground Category	Input Configuration	Our view
Common Ground	Single-Ended Inputs	Recommended
Common Ground	Differential Inputs	Acceptable
Common Mode	Single-Ended Inputs	Not Recommended
Voltage < +/-10V
Common Mode	Differential Inputs	Recommended
Voltage < +/-10V
Common Mode	Single-Ended Inputs	Unacceptable without
Voltage > +/- 10V		adding Isolation
Common Mode	Differential Inputs	Unacceptable without
Voltage > +/-10V		adding Isolation
Already Isolated Grounds	Single-ended Inputs	Acceptable
Already Isolated	Differential Inputs	Recommended
Grounds

The following sections depicts recommended input wiring schemes for each of the 8 possible input configuration/grounding combinations.

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