SUPPLEMENT Bose® Model 1801/1800 Power Amplifier Q4, part number 102428 and Q5, part number 102429 are no longer available with the lead length needed for soldering to the PCB. Use the part numbers listed below when ordering these transistors. Make a note in your Model 1801/1800 power amplifier service manual, part number 192527. Reference Designator Q4 Q5 Description SIM, 2N2219 SIM, 2N5415 Part Number 102428-1K 102429-1K Note 1 2 NOTE: The part numbers listed are kits.
Contents Specifications ................................................................................................................................... 2 Safety Information ............................................................................................................................ 3 Electrostatic Discharge Sensitive (ESDS) Device Handling ........................................................ 4 Disassembly/Assembly Procedures ............................................................
SPECIFICATIONS Mechanical Dimensions: 1801 7 3/16" H x 18" W x 18 1/2" D (Including Knobs) 81/4"H x 19"W x 15"D (not including handles) 1800 Weight: 1801 82 95 80 91 1800 lbs lbs (shipping) lbs lbs (shipping) Power Requirements Voltage: 105-125 AC USA, 210-250 AC EUR Frequency: 50-60 Hz Power Consumption: Minimum 60 watts Normal 1000 watts Maximum 1960 watts Integral Design™ Amplifier Output : (both channels operating ) 250/250 watts @8 ohms 400/400 watts @4 ohms Harmonic Distortion: (THD) @
SAFETY INFORMATION 1. Parts that have special safety characteristics are identified by the symbol on schematics or by special notes on the parts list. Use only replacement parts that have critical characteristics recommended by the manufacturer. 2. Make leakage current or resistance measurements to determine that exposed parts are acceptably insulated from the supply circuit before returning the unit to the customer. Use the following checks to perform these measurements: A.
ELECTROSTATIC DISCHARGE SENSITIVE (ESDS) DEVICE HANDLING This unit contains ESDS devices. We recommend the following precautions when repairing, replacing or transporting ESDS devices: • Perform work at an electrically grounded work station. • Wear wrist straps that connect to the station or heel straps that connect to conductive floor mats. • Avoid touching the leads or contacts of ESDS devices or PC boards even if properly grounded. Handle boards by the edges only.
DISASSEMBLY/ASSEMBLY PROCEDURES 1801 Power Amplifier Note: Refer to Figure 1 for the following procedures. 4.3 Connect the wire harness, thermal cutout wires, and the input cable to the PCB. 1. Top Cover Removal 5. Front Panel Removal 1.1 Remove the two screws that secure the top cover at the rear of the unit. Loosen the two screws located on each side of the unit towards the front. 5.1 Perform procedure 1. 5.2 Remove the nut securing the top of the front panel.
DISASSEMBLY/ASSEMBLY PROCEDURES 1801 Power Amplifier Note: Refer to Figure 5 for the following procedures. 9. LED PCB Removal 12.2 Place the meter lamp housing over the meters and secure it to the front assembly. 9.1 Perform procedure 7. 12.3 Perform procedure 8. 9.2 Unsolder the wires to the LED PCB and make a note of the wiring configuration. 13. Front Panel Controls Removal 13.1 Perform procedure 7. 9.3 Remove the center nut located on each side on the LED lamp housing. 13.
DISASSEMBLY/ASSEMBLY PROCEDURES 1800 Power Amplifier Note: Refer to Figure 1 for the following procedures. 5. Front Panel Removal 5.1 Perform procedure 1. 1. Top Cover Removal 5.2 Locate and remove the eight screws holding the front panel to the chassis. Four of the screws are located just inside the two handles and the other four are the larger screws on the front panel. 1.1 Remove the four screws that secure the top cover to the unit. 1.
DISASSEMBLY/ASSEMBLY PROCEDURES 1800 Power Amplifier Note: Refer to Figure 6 for the following procedures. Note: Refer to Figures 3, and 4 for the following procedures. 9. Gain Control Removal 13. Rear Panel Removal 9.1 Perform procedure 5. 13.1 Perform procedure 1. 9.2 Remove the gain control knobs. 13.2 Locate and remove the four screws securing the rear panel and the rear panel bracket to the unit. Note: One of the screws holds the ground wires to the chassis.
TEST PROCEDURES 1. Bias Adjustment Setup and Procedure 4. Power Output Procedure 1.1 Locate the -85V negative terminal found on the capacitor (C4). See Figure 1 for the location of C4. 4.1 Connect an 8 ohm, 250 Watt load to the output. 4.2 Apply a 1.75Vrms, 1kHz signal to the input. Note: The 1801 and very early 1800's had two lugs on the caps. One with two or three wires and one single wire. The later production 1800 had three lugs on the capacitor.
Figure 1. 1801 Component Location Figure 2.
Figure 3. 1800 Front Panel Figure 4. 1800 Rear View of Front Panel Figure 5.
Figure 6. 1800 Rear Panel Figure 7.
PART LIST NOTES 1. This part is not normally available from Customer Service. Approval from the Field Service Manager is required before ordering. 2. The reference designators in bold are located on the LED PCB. 3. This part is not located on the PCB'S. 4. The reference designators marked with a ‡ symbol are located on the Front Panel. 5. The part numbers listed with SIM are selected components and may not be directly interchangeable with standard available parts. 6.
PART LIST Main Part List (per figures 1-7) Item Number A1 RT-1, RT-2 ¥ Q10-23 Q10-23 Q10-23 Q10-23 Q4, 5 ¥ ¥ ¥ ¥ ¥ S1 S1 S2 S3 J3, 4 (J5, 6 1801 ) R5, 6 R5, 6 1 2 3 4 5 5 M1, 2 B1-4 B5, 6, 7 B8 K1 6 7 T1 T1 T1 Description Preload Network Thermal Cut-Out RCA Jack Screw, 6/32 x 1/2 Stainless Steel Washer Plastic Insulator Nut, Brass, 6/32 x 5/16 x 1/8 Heat Sink Assy Top Wiring Harness Bottom Wiring Harness Top Wiring Harness Bottom Wiring Harness Audio Cable Toggle Switch, ON/OFF Switch, ON/OFF Input Switch
PART LIST Main Part List (per figures 1-7) Item Number 8 F1 F1 F1 ¥ ¥ 9 10 11¥ 12 13 14 15 16 17 18 19 ¥ ¥ 20 21 22 23 24 25 Description Part Number Rubber Foot 121929 Fuse (110v)15A, 1 1/4 x 1/4Slo-Blo 103608 Fuse (220v) 8A, 5 x 20mm 108190-800 Fuse (220v) 7A, 1 1/4 x 1/4Slo-Blo 103609 Fuse Cap for 1 1/4 x 1/4 109484 Fuse Cap for 5 x 20mm 109493 Front Panel Assy 103380 Front Panel Assy 121910 Rear Panel Assy 103282 Rear Panel Assy 103266 Amp PCB Complete 102735-1 L.E.
PART LIST Resistors Reference Designator R1-4 R2 R3 R9, 17 R11 R12, 51, 53 R13 R18, 20, 48 R25, 26 R31-36, 41-46 R37-39 R47 R50 R52, 54 R55, 57 R56 R1,3,101,103 R2,4,10,13,16,19 102,104,107,110 113,116,119 R5,105 R6,9,106,109 R8,108 R11,111 R12,15,18,112, 115,118 R14,114 R17,117 R20,120 R21,121 R22,122 Description 1MΩ, 1/2W, 10% 8.2kΩ, 1/2W, 10% 3kΩ, 2W, 10% 6.19Ω, 1/4W, 1% 1.5kΩ, 1/4W, 1% 340Ω, 1/4W, 1% 100Ω, Bias Pot 23.7kΩ, 1/4W, 1% 182Ω, 1/4W, 1% 0.8Ω, Wirewound, 3W, 5% 0.4Ω, Wirewound, 6W, 5% 4.
PART LIST Capacitors Reference Designator C1‡, 2‡ C1, 14, 15 C1,101 C2, 3 C3, 4 C5 C5, 16 C6, 7, 10, 11 C8 C9 C12, 13, 17 Description 1uF, Mylar, 50v, 10% .1uF, Electrolytic, 100v, 10%, NP 100uF Electrolytic, 3v 30uF Electrolytic, 100v 14,000uF, Electrolytic, 100v 18,000uF, Electrolytic, 10v 27pF, Ceramic Disc, 25v, 10% .
Bridge Rectifier Turn On Relay Figure 9.
Figure 10.
Figure 11.
Notes: 1. See Bias Adjustment Procedure. 2. U1 input (pin 2) virtual ground, output test point 8 (pin 6) 275mV. 3. Early production units replace R28 with capacitor C15 (0.1uF) found in either side of the pc board. 4. All resistors are 1/2 watt 5% unless otherwise specified. 5. All capacitor in uF unless otherwise specified. Figure 12.
Figure 13.
TROUBLESHOOTING GUIDE SYMPTOM 1. DC Offset: POSSIBLE CAUSE ≤2v Defective U1 Defective Q1 ≥2v Defective U1 Defective CR1, 2, 6, 15 Open ground at the RCA input jack Defective Q1-8, Q24 Defective CR16, 17 Test point "A" polarity the same as DC offset (see Figure 11) Short between transistor and heat coupler Shorted driver or output transistor Trouble shoot (by removing collector screws) in this sequence. 2.
VOLTAGE CONVERSION INSTRUCTIONS 1. Perform Top Cover removal procedures for the model amplifier your going to convert. 2. Refer to the figures below for the voltage conversion being performed. 3. On the 1801 when converting to 110 volts remove the in-line resistor found wired to the thermal cutoff indicator. Connect the wire directly. For 220 voltage conversion connect a 56k ohm 1/2 Watt resistor directly to the thermal cutoff indicator terminal. 4. Use an MDL 10 amp fuse for 110 volt operation. 5.
SERVICE BULLETIN Subject: Interchangeability of repaired amplifier PCB. Torroidal Power Transformer. 1800 Amplifier used with a TC-18 Transit Case. Date: 09/19/1977 Bulletin #13 Remarks: The 1801 power amplifier board ( part # 102735 ) will no longer be shipped as a standard repair part. Instead, a universal replacement board ( part # 102735-1 ) with a special thermostatic clip connection allowing the use of this board in the 1801 and early production 1800 wire harness assembly.
SERVICE BULLETIN Subject: Resistor Failure Date: 09/19/1977 Bulletin #13A Remarks: We have found that the resistor R3 on the 1801/1800 amplifier PCB's have shown a higher failure rate than normal. Studies reveal that the resistor normally runs at about 150-170°F. The etch layout at R3 is not sufficient to provide adequate heat sink for this component, and the resistor eventually changes value due to the heat. This changing value causes the resistor, capacitor C2, and the zener diode CR15, to fail.
SERVICE BULLETIN Subject: Thermal Improvement Date 10/05/1979 Bulletin #17 Remarks: I'm pleased to inform you that we have developed a method for improving the thermal stability of the 1800 amplifier, which may have been a problem to you during the last several months. This problem was caused by a change we were forced to make when RCA discontinued the manufacture of the transistor we had been using as Q3 on the 1800 PCB's.
SERVICE BULLETIN Subject: Output Transistors Date: 10/13/1980 Bulletin # Pro-81-001 Remarks: Due to supply demands, Bose® Corporation has changed the output transistors on the PM-2 and the 1800 amplifier boards currently being produced. The transistors have been change from Bose P/N 102433 (2N5840) to P/N 117579 ( Motorola MJ15011). The new output transistors are not compatible with the original 102433 transistors.
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® ® Bose Model 1801/1800 Power Amplifiers © 1997 Bose Corporation Service Manual Part Number 192527 REV 01
SPECIFICATIONS AND FEATURES SUBJECT TO CHANGE WITHOUT NOTICE ® ® Bose Corporation The Mountain Framingham Massachusetts USA 01701 P/N 192527 REV.
