Altec 9444b service manual

Page 2

Operating and Service Instructions for the Altec Lansing 94443 Power Amplifier

Table of Contents

1 ELECTRICAL ...............................................................
1.1 120 V ac, 50/60 Hz Power Connections ............................................
1.2 220/240 V ac, 50/60 Hz Power Connections .........................................

2 INSTALLATION .............................................................
2.1 Rack Mounting .............................................................
2.2 Ventilation ................................................................

3 SIGNAL CONNECTIONS ...................................................... ;
3.1 Input Connections ........................................................... '
3.2 Line Output Connections ...................................................... :.
3.3 Output Connections .......................................................... z
3.4 Output Cable Selection ........................................................ ;

3.4.1 Calculating Power Losses with 8 ohm Loads .....................................
3.4.2 Calculating Power Losses with 4 ohm Loads .....................................
3.5 Damping Factor .............................................................
3.5.1 Calculating the memoir: Length of Cable for a Specified Damping Factor ..............
3.6 Speaker Protection Fuse Selection ...............................................
3.7 Compression Driver Protection Capacitors .........................................

4 OCTAL ACCESSORY SOCKETS ................................................

5 PROTECTION SYSTEMS .....................................................
5.1 103d Protection Circuitry ......................................................
5.2 Amplifier Protection Circuitry ..................................................
5.3 Protect Indicator ............................................................

6 OPERATION ................................................................
6.1 Dual Mode of Operation .......................................................
6.2 Bridge Mode of Operation .....................................................

7 IN CASE OF PROBLEMS .....................................................
8 SPECIFICAHON ............................................................ v-

9 SERVICE INFORMATION ..................................................... '4
9.1 Trimpot Adjustments ......................................................... L:
9.2 Equipment Needed ........................................................... L
9.3 Adjusting R39, the LF Cancel Trimpot ............................................ ' L
9.4 Adjusting R26, the BIAS Trimpot ................................................ :
9.5 Adjusting R23 and R24, the Negative and Positive Current Limit Irimpots ................. n:
9.6 Checking the Short Circuit Current .............................................. '
9.7 Ordering Replacement Parts ...................................................
9.8 Factory Service .............................................................
9.9 Technical Assistance .........................................................

10 THE 9444BISA .............................................................. ,4

i ALTEC LANSINGD CORPORATION O a Mark IV Company