JBL MPA275 - Manual (Page 3)

2
Cautions .................................................................................................................1
Unit Description ....................................................................................................3
General Information ....................................................................................................3
Open Input Architecture™ Slots .................................................................................3
Feature Identification...................................................................................................4
Installation .............................................................................................................5
Inputs ...........................................................................................................................5
Outputs ........................................................................................................................5
Input Connections .......................................................................................................6
Changing XLR Polarity.................................................................................................7
To Parallel the Inputs ..................................................................................................7
Bridged Mono Mode ...................................................................................................8
AC Power Connection .................................................................................................9
Operation .............................................................................................................10
Controls ......................................................................................................................12
Gain Control Lockout ................................................................................................12
Displays ......................................................................................................................12
Typical Power Up, Operation, Power Down Behavior...........................................12
Maximum Long-Term Output Power........................................................................14
Protection Circuits......................................................................................................14
Specifications .......................................................................................................16
Power Output Ratings ...............................................................................................17
Troubleshooting ..................................................................................................19
Illustrations
Figure 1. Open Input Architecture Slots.....................................................................3
Figure 2. Rear and Front Views of 2-Space High Amplifiers ....................................4
Figure 3. Rear and Front Views of 3-Space High Amplifiers ....................................4
Figure 4. Neutrik Speakon Connector Wiring for Speaker Outputs .........................5
Figure 5. Typical Unbalanced Connection.................................................................6
Figure 6. Portable Balanced System ...........................................................................6
Figure 7. Installed Balanced System ...........................................................................6
Figure 8. Ground Bus Connection..............................................................................6
Figure 9. Jumper Positions for XLR Polarity Reversal................................................7
Figure 10. Switch Settings for Bridged Mono Operation...........................................7
Figure 11. Connection Options of Speaker Load for Bridged Mono ......................8
Figure 12. Speakon Connection Details for Bridged Mono Operation. ...................8
Figure 13. Gain Control Lockout...............................................................................12
Figure 14. LED Displays During Normal Operation ................................................13
Figure 15. LED Displays During Abnormal Operating Conditions .........................13
Tables
Table 1. JBL MPA Series AC Power Consumption
versus Load Impedance With 110, 115 & 120 V Mains ..............................9
Table 2. JBL MPA Series AC Power Consumption
versus Load Impedance With 220, 230 & 240 V Mains.............................10
Table 3. LED Display Operation ...............................................................................11
Table 4. Output Ratings With 110, 115 and 120 V Mains........................................16
Table 5. Output Ratings With 110, 115 and 120 V Mains........................................17
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