USB Dual Pre User’s Manual
IMPORTANT SAFETY INSTRUCTION – READ FIRST This symbol, whenever it appears, alerts you to the presence of uninsulated dangerous voltage inside the enclosure-voltage that may be sufficient to constitute a risk of shock. This symbol, wherever it appears, alerts you to important operating and maintenance instructions in the accompanying literature. Please read the manual. Read instructions: Retain these safety and operating instructions for future reference.
INTRODUCTION: 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-inch TRS. Each of the 1/4-inch TRS outputs is buffered low impedance balanced.
CONNECTIONS: Left and Right “Combo” jacks on the front allow for either XLR or 1/4-inch TRS input connections. The XLR Input connections are used primarily for balanced microphone input. Pin 2 is positive, pin 3 is negative, and pin 1 is ground. +48 Volt phantom power (when enabled) is supplied to pins 2 and 3 and pin 1 acts the ground return. Do not lift pin 1 when using phantom power.
The USB connector is USB 1.1 compliant and should be used to connect directly to one of the USB connections on your computer. This connection also powers the USB circuitry inside the USB Dual Pre and will power the whole product if no other power source is available or active. To your computer this connection looks like a “USB Audio CODEC” and your computer then controls the sample rate.
CONTROLS and OPERATION: The Left Gain and Right Gain Controls directly adjust the input amplifiers giving you control over the dynamic range of your source. You get from 0 to 48dB of gain depending on settings. Set the controls counterclockwise to minimum gain when connecting the inputs. The Monitor Mix control allows you to directly blend between the internal preamplifier signals and the playback signals from your computer.
The Power switch, on the rear, is used to turn on power from the battery or external power supply. Turning this switch off disables these two power sources but if the USB bus is still active then the USB Dual Pre will be powered by the USB bus alone and the red power LED will still light to indicate that USB power from your computer is still on.
USB OPERATION: Connect your analog jacks and external power supply first. If you are using one of the analog outputs for local low latency monitoring, connect that to your monitor system or headphones. Next, set the front panel controls for proper operation as per the previous sections. Then connect the USB cable to the appropriate input on your computer and lastly to the USB connector on the USB Dual Pre.
APPLICATIONS: Microphone Pre Amplifier: The USB Dual Pre can be used as a high quality microphone preamplifier suitable for all dynamic, condenser, and ribbon microphones. Most conventional mixers utilize budget minded microphone preamps and while very functional, they do not sound all that great. The USB Dual Pre serves as a quality upgrade that will give you more flexibility and a more robust tone than standard mixer preamps. Simply plug a microphone into the XLR input.
WARRANTY INFORMATION: Limited Warranty Applied Research and Technology will provide warranty and service for this unit in accordance with the following warrants: Applied Research and Technology, (A R T) warrants to the original purchaser that this product and the components thereof will be free from defects in workmanship and materials for a period of three years from the date of purchase.
SPECIFICATIONS: Frequency Response: 20 Hz – 20 kHz (+0, -1 dB) THD: <0.
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