TOA Electronics DA-550F CE Benutzerhandbuch

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10. PROTECTION OPERATION LIST
 Failure
Protection
Operation Indicator
Remedy
Recovery
Overcurrent due 
to overload
Current limiter activated 
when impedance drops 
below the specified 
value. 
Peak indicator lights.  Remove overload.
Connecting a correct load 
automatically restores 
normal operation. 
Short circuit
Current limiter activated. 
Load is disconnected.
Protection indicator 
lights. 
Check speakers and 
lines for short circuit.
Turn off the power switch. 
Correct the load, then 
switch on the power.
Temperature rise
at power amp.
heat sink 
(over 100°C)
Load disconnected.
Protection indicator 
lights.
Temperature rise 
at power supply
heat sink 
(over 80°C)
Built-in amplifier unit 
that caused the failure 
halted.
Four indicators of 
the corresponding 
channel extinguish.
Check the unit for 
correct ventilation and 
overload. 
Operation automatically 
returns to normal when 
the temperature decreases.
Abnormal DC  
voltage output
Load disconnected.
Protection indicator 
lights.
Contact the TOA dealer where the unit was 
purchased.
9. INPUT SENSITIVITY SETTING
The input sensitivity for each channel can be set to either +4 dB (factory preset) or –10 dB. 
These servicing instructions are for use by qualified personnel only. To avoid electric shock, do not
perform any servicing other than that contained in the operating instructions unless you are qualified to
do so. Refer all servicing to qualified service personnel.
CAUTION
Step 1. Unscrew 9 screws securing the top cover
of the unit, then detach it.
Step 2. Insert the jumper socket into either "+4 dB"
or "–10 dB" position as shown at right.
When a bridge connection is made 
(DA-550F only);
Set the input sensitivity with the CH1
jumper socket when Channels 1 and 2 are
bridge-connected. Similarly, set the input
sensitivity with the CH3 jumper socket
when Channels 3 and 4 are bridge-
connected. (Input sensitivity settings for
the CH2 and CH4 are disabled.)
Step 3. Replace the detached top cover. 
–10 dB/+4 dB
Input 
Sensitivity
Input 
Sensitivity
–10 dB/+4 dB
[When set to +4 dB]
[When set to –10 dB]
Jumper 
socket
Jumper 
socket
(Factory-preset)
Viewed from top with the top cover detached.
Front panel
CH 1
CH 2
CH 3
CH 4