User manual ART 355

[. . . ] However, the two signals will sum and the signal present at the XLR jack will tend to attenuate the signal of the 1/4" input. Both balanced and unbalanced output connections may be used simultaneously. This is particularly useful when using the Dual MP as a direct box for instruments or line level signals. **Note: If you experience a grounding hum when using both output connectors (one to the console, one to an instrument amp) simultaneously, a ground loop may be the problem. [. . . ] You'll find the output signal has an enhanced bottom to low mid quality with smooth high frequency detail. The last LED is labeled "Clp" (Clip). This LED will light at approximately 6dB before audible distortion occurs. The unique design of the Dual MP causes the tube to distort well before any other gain stage. When a tube goes into distortion it is a gradual process and tends to sound pleasing for a range before it turns into a distortion box. After some use you'll find the "sweet spot" of the Dual MP is with this light flashing fairly regularly. +20dB Gain/ Norm Switch Use the +20dB Gain/ Norm switch to set the gain range of the Input control. When the switch is in the out (Normal) position the gain range is +6 to +40dB. Depressing the switch adds 20dB of gain. With the switch in, the gain range is +26 to +60dB. With most microphone applications you'll find using the Dual MP with the +20dB gain switch in is needed in most situations. Using a transformerless design throughout, the Dual MP maintains exceptional signal integrity and extremely low noise. The Active balanced input utilizes a hybrid multiple paired transistor design providing extremely low noise and excellent CMRR. A second stage 12AX7A tube running on a regulated DC voltage of +50volts provides additional gain. The tube will overload before the input or output stage. This allows the user to manipulate the tube gain to meet their sonic requirements. The 1/4" input has a high impedance preventing the loading of any device connected to it, making the Dual MP perfect for DI applications. Applications Preamp The main application of the Dual MP is a microphone preamplifier. Plug any microphone directly into either input and set the input and output controls to provide a healthy level into the next stage of your system. DI The Dual MP is ideal for use as a DI box. Plug the instrument into either input and use the XLR or 1/4 (or both) outputs to connect to your recorder, board or PA system. 2-mix Because of its low noise and excellent tonal qualities, the Dual MP is ideal for running mixes through before recording to DAT or cassette. [. . . ] For service outside the United States, please contact your authorized A R T distributor. 1) Be sure the unit is the cause of the problem. Check to make sure the unit has power supplied, the proper power supply is being used (note the output specification of the power supply make sure you are using the proper AC or DC voltage), all cables are connected correctly, and the cables themselves are in working condition. 2) If you find the unit to be at fault, write down a description of the problem, including how and when the problem occurs. 3) Call the factory for a Return Authorization (RA) number. [. . . ]