background image

ES 

Figure 

2. 

Typical Frequency  Response 

DATA CONTENTS 

INSTALLATION 

RACK INSTALLATION 

SHELF INSTALLATION 

VENTILATION 

ELECTRICAL 

120 

Volt, 

Hz Power Connections 

240 

Volt, 

H z  

Power Connections 

Battery  Connections 

lnput Connections 

Output Connections 

Speaker Matching 

Speaker Power Distribution 

SPECIFICATIONS 

DESCRIPTION 

OPERATION 

Page 

Graphics 

Figure 1. 

Typical Power Output Versus Fre- 
quency  for 0.5% THD and 1% THD 

(8-Ohm Load) 

CONTROLS  AND INDICATORS 

FILTER 

Page 

SERVICE 

ACCESS 
ADJUSTMENT OF POWER  DRIVER 

BALANCE CONTROL 

ADJUSTMENT  OF OUTPUT 

CONTROLS 

ASSEMBLY  REPLACEMENTS 

Fuses 

Pilot Lamp 

Power Driver PCB 

RECOMMENDED  SERVICE TECHNIQUES 

Transistor Orientation 

Replacing Power  Transistors 
Testing Transistors 

Replacing PCB Components 

Repairing Fractured or Damaged PCB 

Conductor 

Characteristics 

Figure 

3. 

Typical % THD  Versus Frequency 

for  100-Watt Output 

Figure 4. 

Typical 

THD  Versus Wattage Out- 

put at 1000 

Hz 

Load) 

Figure 

5. 

Front View With Hinged Panel Open 

Figure 6. 

Rear  View of 

Power  Amplifier 

Figure 

7. 

Converting to 240V ac, 

Hz 

Operation 

Figure 

8. 

Socket Wiring for Transformer- 

Isolated lnput Using 

Line 

Transformer 

Table 

Speaker Outputs 

Figure 9. 

Typical Solid-State Component 

Configuration 

Figure 

10. 

Component  Locations Inside Main 
Chassis 

Figure 

Component  Locations on Rear  of 

Chassis 

Figure 12. 

Schematic 

Amplifier 

Figure 

Component Locations 

Power Driver PCB  Assembly 

Table I. 

Terminals and Applications  of  INPUT 

Terminal  Board 

PARTS 

Summary of Contents for 1594B

Page 1: ...onif AC Power 35 Hz to 20 kHz Fails Transformer Isolated Outputs for 4 8 and 16 Ohms and Low Power Consumption for 25V and 70 7V Distribution Systems Low Heat Generation Switchable Highpass Filter Protects Driver Loudspeaker from Excessive Low Frequency Power Demands Hinged Front Panel for Easy Maintenance Exclusive Active Dissipation Sensing Circuit Protects Output Transistors Small Size AC or Ba...

Page 2: ...QUES Transistor Orientation Replacing Power Transistors Testing Transistors Replacing PCB Components Repairing Fractured or Damaged PCB Conductor Characteristics Figure 3 Typical THD Versus Frequency for 100 Watt Output Figure 4 Typical THD Versus Wattage Out put at 1000 Hz 8 OhmLoad Figure 5 Front View With Hinged Panel Open Figure 6 Rear View of 15948 Power Amplifier Figure 7 Converting to 240V ...

Page 3: ...ypically less than 10 of load impedance 85 dB below rated output 1 VOLUME control continuously variable 1 primary power ON OFF switch 1 FILTER IN OUT switch rear panel 1201240V ac 50160 Hz 20W at zero signal 180W at 33W output 290W at 100W output or 24128V dc 0 2A at zero signal 5 OA at 33W output 8 5A at 100W output Battery minus is ground Up to 5 5 131 F ambient 7 H x 1 9 W x 8 112 D 35 pounds 8...

Page 4: ...helf use I t tilts the 15948 for easy accesr to front panel controls The sides and top extend beyond the front panel to preventaccidental changes of control settihgs The cover provides easier handling for portability and i t is sturdy enough to support lightweight equipment placed on top of it Four polyethylene feet prevent marring of sur faces The ALTEC green finish matches the front panel of the...

Page 5: ...lation past the output transistors ELECTRICAL 120 Volt 50160 Hz Power Connections Equipment supplied for domestic use is provided with the power transformer primary strapped for 120 volts terminals B A T T E R Y P O W E R TERMINAL BOARD TB4 1 to 2 and 3 to 4 on TB3 The power input nameplate adjacent to the power cord on the chassis is mounted to show the appropriate side specifying the connections...

Page 6: ...hen shipped from the factory pins 3 and 4 of J1 are strapped together to provide a 600 ohm input A 150 ohm input may be obtained by removing the strap from pins 3 and 4 and then strapping pins 1 and 4 and pins 3 and 6 see Figure 8 I Direct Coupled Isolated linesof 150or 600ohms up to level of 15 dBm with 15095A Line Transformer For low impedance line bridging input or 15K ohrn line matching input ...

Page 7: ... see Figure 2 A screwdriver operated FILTER IN OUT switch is located on the rear of the chassis see Figure 6 The switch is placed in the OUT position when the 15948 is hipped from the factory SERVICE If a malfunction occurs service should be performed by an ALTEC Qualified Service Representative For factory ser vice ship the 15940 prepaid to Customer Service ALTEC 1515South Manchester Avenue Anahe...

Page 8: ...the required length and insert them properly indexed into the PCB or socket ReplacingPower Transistors The ac primary power fuse is mounted on the front panel see cover photo The battery power fuse is located on the rear of the chassis see Figure 6 I f fuse replacement is re quired determine and correct any cause of failure before re plac ng fuse Install an identical fuse see PARTS LIST by unscrew...

Page 9: ...Lead 1 Emitter TO 5 L e a d 2 B a s e Lead 3 Collector P Case 3 If component is faulty or damaged clip leads close to component and then unsolder leads from board With draw leads from component side 4 Clear solder from circuit board holes before inserting leads of new component Heat solder remaining in hole remove iron and quickly insert a pointed non metallic object such as a toothpick from condu...

Page 10: ...VE PCB ASSEI BLY A l I I I I 3 I t i I i 1 I I N LOWERED POSITION 1 13 Figure 10 Component Locations Inside Main Chassis T 1 VOLTAGE Q b Q5 TBI RATING PLATE SINK Figure 11 Component Locations on Rear of Chassis ...

Page 11: ......

Page 12: ......

Page 13: ...2N5305 selected Transistor 2N2712 selected Transistor 2N3906 selected Transistor 2N5308 low noise selected 47 01 102169 01 Res 3 3Ka 210 Il14W 48 03 107447 02 47 06 042509 01 47 01 100635 01 47 02 105885 01 47 01 100652 01 47 02 114449 01 47 01 102054 01 47 01 102057 01 47 02 112166 01 47 01 102551 01 47 02 100715 01 47 02 100712 01 47 01 102376 01 47 01 100479 01 47 01 102190 01 47 01 102171 01 4...

Page 14: ... Res 3 3 R z L 114W Pot 10a 2 2 W Res 330Q 210 1W Res 27Q 10 li4W Res 47Q 10 1 2W Res 180a lo 112W R136 137 R138 133 Res 56a 10 114W 47 05 y697 01 F a r i i 47 01 102355 01 Res 3 3K Q 5 1 4W Res 22Ka 10 21 04 101034 01 1 IITB4 I Name and Description Res 47Q f10 1 4W Res 220 Q lo 114W Pot 5 0 n 2 0 2W y t Rer 1KCZFIOI 112W Switch DPDT slide Switch toggle 125V ac 3A 20V dc 5A Transformer power Trans...

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