User manual PEAVEY A-A-4000F DATASHEET

[. . . ] Each Mic/Line preamp provides a gain control, phantom power (mic inputs), low cut filter, activity/clipping LED, and a choice between manual or automatic operation. Each channel can be muted externally or multiple channels can be muted externally via an assignable mutebus. in addition , channels one and two provide adjustable priority and a signal processor loop. The master section provides a gain trim control, three sweepable notch filters, a downward expander, a transformer balanced output, and a remote volume port. [. . . ] the LED will start to glow red 6 dB before the preamp begins to clip. NOTCH FILTER LEVEL AND FREQUENCY CONTROLS (11 and 12) The Automix notch filter consists of three sweepable 1/3 octave filters with 0 to 15 dB of cut. These filters can be used to attenuate frequencies that are prone to feedback without adversely affecting the tonal quality of the system. Equalizing these problem frequencies out of the room's frequency response increases the sound system gain before feedback. Notch Filter Level Control (11): The notch filter level control adjusts the amount of cut at the frequency selected by the corresponding frequency control (12). Notch Filter Frequency Control (12): The notch filter frequency control is used to select the center frequency of the notch filter. DOWNWARD EXPANDER (13) The downward expander can be used to attenuate the system gain when all of the input signals are low. This can be used to prevent background room noise from being amplified. Setting the Downward Expander: Have someone speak into a microphone at the softest level you expect to encounter. Slowly turn the downward expander clockwise until the background noise between words is attenuated. The more downward expander that is used, the less "natural" sounding the system will become. LINK PORT (23) To increase the number of inputs available, multiple Peavey Automix's can be linked together. linking automixers is a very simple process. It can be done with a small flathead screwdriver and a length of two conductor shielded wire. Using the small screwdriver, remove the factory installed jumper wires in the link port from the slave unit. Any unit can be used for the system output. The notch filter and master controls will only affect that unit's output. NOTE: When configuring multiple units, the wire jumpers in the ALOAD and the CLOAD must be left in one unit and one unit only. MASTER OUTPUT (24) The master output is a 600 ohm, transformer balanced output that can be used to feed an external power amplifier. When making connections remember to observe proper polarity. Setting the Channel Level: Set the front panel control (of the channel that is being adjusted) to the middle (12 o'clock) position. connect a mic or line input to one channel. [. . . ] If the feedback is still audible turn the level control CW toward the -15 until the feedback is gone. The mixer's levels are now set and the mixer's other features (downward expander, Lo cut and priority) can be set as desired for the application. Attach the security plexiglass with the four supplied screws. This will prevent any unwanted tampering with the settings. [. . . ]