USBPre and Earthworks Microphones
There is some confusion regarding the USBPre and its compatibility with Earthworks microphones.
The USBPre works properly with all models of Earthworks microphones.
While some models of Earthworks microphones are not compatible with transformer-balanced inputs (see Sound Devices tech note Transformer Inputs with Earthworks Microphones ) all Earthworks microphones function properly with the USBPre. The input topology of the USBPre differs from other Sound Devices products; USBPre uses a discrete active-balanced input and provides 48-volt phantom power which Earthworks microphones require.
With the USBPre, Earthworks microphones draw 10 mA of current, which reduces the runtime of notebook computers when powered from batteries.
Contact Earthworks directly at (603) 654-6427 or at http://www.earthwks.com if you have any questions about the compatibility of Earthworks microphones with particular input topologies.