User manual ART USB DUAL PRE PROJECT SERIES

[. . . ] 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. Heed all warnings printed here and on the equipment. Follow the operating instructions printed in this user manual. [. . . ] When using the USB Dual Pre for USB to audio output monitoring of your computers playback signal, you would set the Mix control to "Computer". When set in the middle you get a blend of the direct preamp signal and signals coming from your computer. Some recording programs and computer systems provide what is called a "Play-Through" function. This can be performed through software or hardware. When Play-Through is set to ON, the computer will output the audio that is being recorded. There is a short delay, or latency with this audio signal. There is also a potential for the computer's audio inputs and outputs to be connected together thereby forming a feedback loop. This can accidentally create very loud and disturbing sounds. Therefore "Play-Through" is usually set to OFF as the "default" setting in both software and hardware. If Software/Hardware Play-Through is set to ON and the Monitor Mix is set in the middle, then you will most likely hear the original preamp signal together with the computer audio signal slightly delayed, thereby creating an echo effect. This is normal behavior, so while using various Monitor Mix settings it may be preferable to leave Play-Through set to OFF. The Monitor Level control adjusts overall monitor level after the mix circuitry and before the monitor output amplifiers. This control affects the signal levels at both the 1/8-inch headphone and 1/4-inch balanced monitor output jacks. The Phantom power switch, on the rear, applies +48 Volt phantom power to the XLR input jacks for powering microphones, if needed. It is slow at turning on and off and is current limited to protect sensitive microphones and reduce audible pops. It is not lit, even when on, to maximize battery life. Ideally, when connecting a microphone that requires phantom power, you should first turn down gain, next connect the microphone, next switch on the phantom power, and finally bring the gain back up to the desired level. This minimizes pops in your system and stress on the microphone. 6 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. This is in fact incorrect and could create higher overall noise. ART preamps are actually intended to output a nice fat LINE LEVEL signal. If you send that line level signal to a recorder or mixer's Mic input, that circuit will usually add more gain to the signal. Gain on top of gain will indeed result in noise. Please treat the output signal as line level and you'll be pleasantly surprised at your new clean and warm sound. [. . . ] Adjust the input gain knob and refer to the LEDs on the front for a visual measure of input gain. Then route the output to a mixer, workstation or computer via the 1/4-inch, or USB output. The overall output can be adjusted at the unit. Both analog outputs and the USB port may be used at the same time so the 1/4-inch can be routed to an amplifier or monitor system and the USB to a computer. [. . . ]