On very old Odin's Ravens, the modchip may be getting its power from the voltage regulator point that is near the microphone port. I'm assuming this is the same power source as the Turtle Beach. I'm talking old Odin's Raven like probably before about March 2010 (if your circuit board is a CG1 circuit board). I'm wondering if there is a possibility that too many third party devices are trying to draw too much power from the port at the same time. I don't know how to confirm or deny this however, short of trying to remove the modchip and seeing if the headset works.
Unfortunately I faintly remember trying this back in 2010 and discovering that the turtle beach still didn't work, while a stock headset did. So I adopted the official stance that our controllers are not guaranteed to work with third-party headsets. We did guarantee our controllers to work with stock microsoft headsets.
Are you any good with a soldering iron?