User manual ALTEC LANSING 299-16A HF DRIVER

[. . . ] UNPACKING As a part of our system of quality control, every Altec Lansing product is carefully inspected before leaving the factory to ensure flawless appearance. Save the shipping carton and all packing materials , as The lightning flash with arrowhead symbol, within an equilateral triangle, is intended to alert the user to the presence of uninsulated "dangerous voltage" within the product's enclosure that may be of sufficient magnitude to constitute a risk of electric shock to persons. CAUTION RISK OF ELECTRIC SHOCK DO NOT OPEN TO REDUCE THE RISK OF ELECTRIC SHOCK, DO NOT REMOVE COVER. TO REDUCE THE RISK OF FIRE OR ELECTRICAL SHOCK, DO NOT EXPOSE THIS APPlIANCE TO RAIN OR MOISTURE. REFER REPLACEMENT TO QUALIFIED SERVICE PERSONNEL. The exclamation point within an eqilateral triangle is intended to alert the user to the presence of important operating and maintenance instructions in the literature accompanying the device. WARNING: THIS APPARATUS MUST BE EARTHED 3 Operating Manual -1662A Mic/Line Mixer 4. [. . . ] The clip LED turns on whenever any portion of the audio path within the input channel reaches a level 3 dB below actual clipping. 4. 3 Tr eble and Bass Contro l s Tr Contro These controls are used for broad EQ changes to each input channel. Channel EQ consists of a high shelf control (treble) at 8KHz, and a 90Hz low shelf control (bass). EQ boost or cut is ±12dB at these frequencies. 4. 4 Input Assign Switch This switch selects the output routing for each input channel. Contro 4. 5 Input Level Contro l This knob adjusts the level of each channel. If a channel's level control is always turned up to 9 or more, try increasing the gain first. Conversely, if the level control is consistently turned down to 1 or less, decrease the gain setting first. Remember that the gain setting should be set as high as possible while still allowing 20dB of headroom. Contro 4. 6 Output Level Contro l s These two controls determine the signal level to the "A" and "B" outputs. They are used to drive power amplifiers for the main loudspeakers, or to connect to a stereo recording device. 4. 7 Output Meters A pair of peak reading 11 segment LED meters are used to indicate stereo output level in VU. Using the sum inputs does not prevent The input pad is a 20dB attenuation switch for extremely loud microphone or line level inputs. It should normally be left in the "out" position for best signal to noise ratio, but can be used when the input is being clipped with the gain and level control at minimum. 6 Operating Manual -1662A Mic/Line Mixer the use of mic inputs on channels five or six, but only one level controls both the mic and RCA inputs. The RCA sum inputs have a nominal operating level of -10dBu to match most consumer audio sources. 6. 5 Outputs The Euroblock "A" and "B" outputs are controlled by the output level master controls. They are active servo-balanced with a nominal operating level of +4dBu into any load, and are capable of driving long lines. 6. 6 +48V Phantom Power Switch This switch applies +48VDC to all six mic inputs for condenser microphones. Phantom power will not affect most dynamic mics, which may be used along with condenser mics. If they are operating, the problem is between the mixer and the later components in the system. If there is no meter activity, check to see that you really have an input signal and that it is on the desired channel. If the clip indicators are active, reduce the channel gain and/or press in the pad switch on the rear panel. There are many gain adjustments in the mixer itself and probably several others in other system components which makes it possible to overdrive an input section and then incorrectly try to reduce the gain of the output section. [. . . ] Also, check that the -20dB rear panel pad switch is not unnecessarily enabled. 7. 4 Excessive hum This is usually caused by "ground loops" in the system wiring. A complex sound system with many sources separated by significant distance and using several power outlets has many opportunities for this problem to occur. If possible, every component in the system should be plugged into the same AC circuit with a common ground. [. . . ]