Crest Audio UMA 4300, Руководство пользователя

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(17) Low EQ (Bass)
This rotary control varies low frequency response from +10 dB to -10 dB at 100 Hz. It is a shelving-type active control and
delivers a flat response in the center “0” position.
(18) High EQ (Treble)
This rotary control varies high frequency response from +10 dB to -10 dB at 10 kHz. It is a shelving-type active control and
delivers a flat response in the center “0” position.
(19) Balanced Input Connectors (Inputs 1 - 4)
The electronically-balanced, variable-gain, input will accept both line and mic level signals and has an input impedance of
3.3k Ohms.
(20) Preamp Gain Controls
The preamp gain controls adjust the sensitivity of the 4 inputs allowing microphone and line level signals to be connected to
the UMA amplifier. Begin by setting the gain at minimum (full CCW). Set the master level and channel level controls on the
front panel in the 12:00 to 2:00 range. Adjust the preamp gain for proper signal level through the system. The Green signal
LED should flash and the Red PK LED should not light.
(21) Dual RCA Input Connectors
The dual RCA input connectors are available on inputs 3 and 4 and provide an easy way to connect a mono or stereo,
unbalanced source to the UMA 4300. The RCA selector switch must be pressed to activate these inputs. There is no phantom
power on these connectors.
(22) RCA Selector Switches
Pressing the RCA selector switch replaces the balanced input with the dual RCA jacks.
(23) Threshold Control
Channel one is the controlling channel of the priority mute system. When the signal level on channel 1 exceeds the threshold
set by the threshold control, channels 2-4 are muted. Setting this control at the full counter-clockwise position defeats the
muting function.
(24) Phantom Power +48V
There are two phantom power switches on the rear of the UMA 4300. The first turns on +48V phantom power for input 1,
the second for inputs 2 and 3.
(25) Mute All
Connecting the two terminals on the mute all input connector, mutes all audio through the UMA 4300. This may need to be
connected to a fire alarm system, for example, to mute audio in case of emergency.
NOTE : For rack mount installations, use 4 machine screws through the front panel mounting holes to secure the amplifier to
the rack rails