User manual ART PRO MPA II

[. . . ] PRO MPA II TM ART PRO MPA II Microphone Preamplifier USER'S GUIDE IMPORTANT SAFETY INSTRUCTIONS ­ READ FIRST This symbol, wherever 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 manual. Read instructions: Retain these safety and operating instructions for future reference. [. . . ] Refer to the application section titled "Adjusting the Input Impedance" for more information on making the most of this function. The ¼" instrument input is NOT affected by this control, and remains high (>1M Ohm) impedance. Low Cut Filter control The Low Cut Filter is a single tuned High Pass Filter that is frequency tunable. The input signal can be filtered to remove "pops" or other extraneous low frequency information. This control moves the rolloff frequency from 10 Hz (fully CCW) to 200 Hz (fully CW). Since it is single tuned, it preserves some low frequency content so its use is less obtrusive. It is especially useful in close mic'd applications. Gain switch The Gain switch is used in conjunction with the input gain control to adjust signal levels through the PRO MPA II. When depressed, the tube circuit provides 20dB more gain in the signal path. This also has the effect of driving the tube harder and making the tube the dominant source of gain and overload character. 4 Phantom switch Phantom power on the microphone input is turned on and off with this switch. Depressing the switch will power condenser microphones and other 48volt phantom powered devices. Phantom power is supplied to pins 2 and 3 of the input jack. NOTE: 1) Dynamic microphones are NOT affected by Phantom power, although it should be turned off when using dynamic microphones or line level inputs. 2) Although the 48volt phantom power ramps up and down slowly it may still create a pop. Mute the output of the PRO MPA II when engaging or disengaging phantom power to prevent damage to equipment following the PRO MPA II . Phase switch The Phase switch can invert the phase of the audio signal path in either channel. It can provide from +10dB of gain (fully clockwise) to completely muted. You can see the effects of this adjustment reflected in the analog meters. STEREO/Dual switch The STEREO/Dual switch selects the operation of the output control knobs. Stereo mode gains and operation are marked with reversed out text. 6 In Stereo mode, CH1 output adjusts the output gain of both channels and CH2 output control acts as a power summed Balance control. There is a slight drop in output level in stereo mode when the Balance knob is centered vs. When the switch is in the "Dual" position the output controls act on only their respective channels. +4/-10 switch (rear panel) The +4/-10 switch is used to set the output level of the PRO MPA II for the appropriate system levels. This feature allows you to match 0 VU on the meters of the PRO MPA II and your mixer or other equipment. When depressed, 0 VU on the output meter corresponds to +4dBu on the outputs. In ­10 mode, the output level measures ­10dBV. [. . . ] Check to make sure the unit has power, all cables are connected correctly, and the cables themselves are in working condition. You may want to consult with your dealer for assistance in troubleshooting or testing your particular configuration. 2) If you believe the ART unit is at fault, go to www. artproaudio. com. You may contact Customer Service for more assistance, or directly request a Return Authorization for service in the "resources" area of the website. [. . . ]