The USB Dual Pre is a full-featured high quality dual portable preamplifier and computer interface packed into a compact rugged case.It is designed to work over a wide variety of applications from remote field recording to desktop/studio tracking. Each of the two low noise input channels has up to 48 dB of clean gain with signal present and clip LED indicators. Inputs can be either XLR balanced or 1/4" TRS. Each of the 1/4" TRS outputs is buffered low impedance balanced.The USB Dual Pre is powered via the USB bus. An internal 9 Volt battery, or optional external 12V power supply (or any combination of USB, battery & power supply) can be used depending on application. When running powered by battery alone, you should expect in excess of 50 hours of operation with phantom power off. Battery life will drop to approximately 20 hours (depending on microphone) when phantom powering is engaged (still enough time to get through an average session).The built-in low noise +48 Volt phantom power supply allows you to power up to 2 microphones as well as the preamplifier when running from any power sources including the USB bus.For monitoring, an 1/8" TRS mini headphone jack with level and monitor mix controls on the rear allow for latency free local monitoring of the inputs while recording as well as playback monitoring of the USB bus. The monitor mix is also routed to the 1/4" TRS balanced outputs. This lets you use the 1/4" outputs as either preamplifier outputs or as the monitor feed to your powered monitors.The USB interface is fully compliant with the USB 1.1 specification and uses USB adaptive mode for playback and USB asynchronous mode for record. It will work with the USB audio device drivers built into Windows 98SE/ME/2000/XP/Vista and Apple OS9.1/OSX computers with native USB support. No special drivers are needed.FeaturesUSB Connectivity to Desktop and Laptop ComputersLow Noise Fully Balanced XLR and 1/4" TRS Combi InputsUp to 48 dB of Clean Gain n Built-in Low Noise Phantom Power SupplyLatency Free Monitoring Mix and Level ControlsIndependent Channel Gain Controls1/4" TRS Balanced Monitor and 1/8" Headphone Monitor OutputsIncludes Audacity Recording & Production SoftwareFlexible 3-way Power from USB, External Supply, or 9 Volt BatteryIncludes USB Cable - Everything Needed To Start Recording TodayWindows 7 UsersUnlike previous versions of Windows, Windows 7 defaults to a single channel and adds too much gain to the signal coming though USB audio devices. There are some things you will want to change in "Control Panel >Sound Settings" to get Windows 7 to work with 2-channel USB audio products.The default setting for the input is 1-channel / 16bit/44.1K. In "Properties", change this to: 2-channel/16bit/44.1K.Windows sets the Mic input gain very high by default, so this needs to be reset.Use the "Configure" button in the Sound window to access the Speech Recognition section and select "Set up Microphone" and select "Other" under the input type.Run a signal into the USB device and run the Windows 7 Speech LevelProgram, following the prompts.After this, the gain levels will be appropriate, and both channels if the unit will be recognized. ART USB-DUAL-PRE-PROJECT USB Dual Pre PS Project Series 2-Channel USB Microphone Preamp.