Sound Devices MixPre-D - Manual (Page 11)

MixPre-D User Guide and Technical Information
9
Powering
The MixPre-D can be powered from either internal batteries or from external DC. The power-efficient
MixPre-D can operate from two AA alkaline batteries for nearly a production day (less with phan-
tom powering). While many users prefer external DC sources to power both their mixer and wireless
receivers, the use of internal batteries is perfectly feasible for both primary and backup powering of
the MixPre-D.
Power Switch and LED
The 3-position power switch selects between internal batteries, external DC, or power off. There is
sufficient capacitance in the power supply circuit to toggle between internal and external without
any disruption in audio.
The power LED illuminates solid green to indicate good power. The power LED flashes green when
the internal batteries are low.
Internal Batteries
The MixPre-D accepts two standard AA batteries (1.2 to 1.65 Volts). The robust battery cap and tube
are sealed to prevent inadvertent battery leakage from reaching internal circuitry. The threaded-nick-
el cap extends beyond the panel to make battery changes easy and quick.
Remove batteries when the unit is stored for extended periods.
External DC Sources
For extended mixer runtime use an external DC source. The MixPre-D can be powered from any DC
source with a voltage range of 10 volts to 18 volts. If an over voltage is applied to the mixer, an inter-
nal poly fuse is opened to prevent mixer damage. The fuse is reset when the voltage is removed.
The external DC supply is isolated (floating) from the circuitry to minimize ground loop and interac-
tion among devices sharing the same DC source. The external DC connector is a Hirose 4-pin female.
This locking connector mates to Hirose P/N HR10-7P-4P (Sound Devices P/N XL-H). Pin-1 is nega-
tive and pin-4 is the positive voltage.
Computer Interface
The MixPre-D is an USB Audio Device Class peripheral. When attached to a computer as an audio
interface, the stereo output bus is sent to the computer as left and right inputs and the left/right
audio output of the computer is sent to the headphone output of the MixPre-D.
No proprietary drivers are required to operate the MixPre-D. The MixPre-D directly operates with
Mac OS 10.4+, Windows XP, Vista, and 7 (both 32- and 64-bit), or Linux ( See Computer System Re-
quirements for details). The first time the MixPre-D is plugged in, the operating system will enable
standard USB Audio Device Class drivers automatically (if necessary).
When connecting the MixPre-D to computers running Linux or any version of Macintosh OS X previ-
ous to 10.5.8, it is necessary to run the MixPre-D in “full-speed” USB mode. To do this, hold down the
Headphone Controller while inserting the USB plug to the MixPre-D.