Toa AX-1000A, Руководство по эксплуатации

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12. Fine-Tuning the AX-1000A Installation
In certain situations, more control over channel Off-Attenuation and system NOM Attenuation is desired.
First, set up the input modules. Then choose the specific inputs which need less than 40 dB of Off-Attenuation and
adjust the controls accordingly.
Finally, select NOM attenuation from 0 to 20 log NOM as required. Set Master Volume appropriate for one
channel. In typical operational circumstances, determine proper NOM setting when many mics are gated "on". If
feedback does not occur in such a situation, turn NOM control slightly toward 0 logNOM, retest, and readjust if
necessary. Similarly, if feedback does occur when many mics gate "on", turn NOM control slightly toward the 20
log NOM position and retest.
13. Using the AX-1000A System Mute Bus
Definitions:
AX-1000A System Mute Bus refers to the Mute Terminals and associated internal circuitry.
Internal Mute; INT.
Refers to an internal AX-1000A mute bus setup which allows certain channels to be shut off in response to a short
across the Mute Terminals.
External Mute; EXT.
Refers to the external muting (900 Series module mute) scheme.
Automatic Module Mute
Refers to a second, independent muting scheme which can be designed into an AX-1000A by choosing the proper
modules.
Internal "Internal Mute; INT" muting occurs at the output of each channel after the direct output and before the
signal reaches the mixing bus. When the terminals on the rear-panel are shorted, any channel which has been set
to mute via the Channel Mute Switches will do so. See the following Configuration 1.
However, the Direct Outputs will not be muted. If the Direct Outputs must be muted, select 900 Series 'mute
receive' modules. See Configuration 2 on page 19.
Configuration 1 : Internal Mute; INT.
A typical application is for a chairman's switch to silence all the delegates in a large meeting room.
Internal Mute occurs with in the mixer, after the signal has left the input module itself. Thus, any channel can be
muted. The module does not have to be a 900 Series 'muting module', its channel simply must be chosen on the
rear-panel DIP Channel Mute Switches. Furthermore, the Direct Output of the channel will not be affected by the
muting.
As shipped, the default is 'on' (channels respond to a short across the mute terminals). To configure Internal Mute;
INT., locate the Channel Mute DIP switch on the rear-panel of the unit. Set the switch corresponding to the
channel(s) which must mute.
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