User manual ART TUBE MP-PROJECT WITH USB

[. . . ] Project Series TUBE MP 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. Power sources: Connect the units power supply to mains power only of the type described in this user manual or marked on the power supply. Power supply: Use the power supply with sealed mains plug appropriate for your local mains supply as provided with the equipment. [. . . ] You get a 45dB gain range when using the XLR input and a 25dB gain range when using the ¼" input. Set the control counterclockwise to minimum gain when connecting the inputs. The Gain Switch gives you an additional 20dB of gain between the input stage and the tube to bring up very low-level signals and allow you to drive the tube harder. This position should be used for most microphones and line level signals to minimize any loading effects on the source. This position terminates the signal with known low impedance that can flatten and clean up the frequency response of some vintage equipment including ribbon microphones, and various transformer coupled outputs. By controlling impedance at the input you reduce the need for added equalization and the response to percussive audio dynamics is tightened in many cases. This helps to cut out low frequency rumble, wind noise, and all types of very low frequency energy before it is amplified. When directly plugging into an instrument amp or microphone input on another piece of equipment you may find that a 9 o'clock position gives you plenty of output. The LED metering circuitry covers a wide 30dB range and has a fast attack to help indicate any clipping. The Output control comes after the meter so that you can use the meter to set the overall input gain for best dynamic range then trim the output signal level to the system you are driving. The red "Clip" LED comes on just before clipping and should light on extreme musical peaks only. The yellow "0dB" LED is set to 15dB below the "Clip" LED. If the "0dB" LED is on half the time then you have about 15dB of headroom on the average. The green "-7" and "-15" LEDs indicate how far below the nominal "0dB" LED your signal is. These LEDs should be on much of the time during performance and if not it indicates that your signal or input gain is too low for best results. The FET limiter has its output level set to be at the "0dB" LED point so if the limiter is engaged and the "0dB" LED is on then you are in limiting. To do this you would start with the limiter off, apply a signal and increase the gain until the red "Clip" LED comes on occasionally, then engage the limiter. At this point the signal at the tubes output will be in limiting much of the time. You can then adjust the Output control so you are just below clipping at your A/D, computer, recorder, or amplifier input. For the built in USB interface this setting would be around 2 o'clock. At this point, as long as the Output control is at the current position, you can use the "0dB" LED to indicate that you are at full signal level for your equipment that follows. When the Iimiter is engaged you can turn the Output control up full with most material before you run into digital clipping. [. . . ] Adjust the input gain knob and refer to the 4 segment LED on the front for a visual measure of input gain. Then route the output to a mixer, workstation or computer interface via the XLR, 1/4", or USB output. The overall output and limiter can be adjusted on the face of the unit. Both analog outputs and the USB port may be used at the same time so the 1/4" can be routed to an amplifier, the XLR to a monitor mixer and the USB to a computer. [. . . ]