The moment of truth… powered up our FAB2010 XLR Input Module for testing. I’m happy to say it works great. The Logic Control Inputs for the 20dB Pad and Phantom Power works as expected.
So basically, if you want to enable PAD or PHANTOM POWER, all you need to do is apply a small voltage to it’s respected logic pins on the board. See photo below. A logic level control voltage can be anywhere from +3.3V to 5V up to your V+ level. These can be switched from hard-wired switches (latching type push-buttons), or from a microprocessor or logic gate chips (TTL or CMOS type).
How it works