Contents |
|
Specifications ................................................................................................................................... |
2 |
Safety Information ............................................................................................................................ |
3 |
Electrostatic Discharge Sensitive (ESDS) Device Handling ........................................................ |
4 |
Disassembly/Assembly Procedures ........................................................................................... |
5-8 |
Test Procedures ............................................................................................................................... |
9 |
Figure 1. 1801 Component Location .............................................................................................. |
10 |
Figure 2. 1801 Side View ............................................................................................................... |
10 |
Figure 3. 1800 Front Panel ............................................................................................................ |
11 |
Figure 4. 1800 Rear View of Front Panel ....................................................................................... |
11 |
Figure 5. 1801 Rear View of Front Panel ....................................................................................... |
11 |
Figure 6. 1800 Rear Panel ............................................................................................................. |
12 |
Figure 7. 1801 Rear Panel ............................................................................................................. |
12 |
Part List Notes ................................................................................................................................ |
13 |
Figure 8. 1801 Front Panel ............................................................................................................ |
13 |
Part List ...................................................................................................................................... |
14-17 |
Figure 9. 1801/1800 Block Diagram ............................................................................................... |
18 |
Figure 10. LED PCB Layout ........................................................................................................... |
19 |
Figure 11. LED PCB Schematic Diagram ...................................................................................... |
20 |
Figure 12. Amplifier Schematic Diagram ........................................................................................ |
21 |
Figure 13. Amplifier PCB Layout .................................................................................................... |
22 |
Troubleshooting Guide .................................................................................................................. |
23 |
Voltage Conversion Instructions .................................................................................................. |
24 |
Service Bulletin ......................................................................................................................... |
25-28 |
PROPRIETARY INFORMATION
THIS DOCUMENT CONTAINS PROPRIETARY INFORMATION OF
BOSE® CORPORATION WHICH IS BEING FURNISHED ONLY FOR
THE PURPOSE OF SERVICING THE IDENTIFIED BOSE PRODUCT
BY AN AUTHORIZED BOSE SERVICE CENTER OR OWNER OF THE
BOSE PRODUCT, AND SHALL NOT BE REPRODUCED OR USED
FOR ANY OTHER PURPOSE.
1
SPECIFICATIONS
Mechanical
Dimensions: 1801
1800
Weight: |
1801 |
|
1800 |
Power |
Requirements |
Voltage: |
|
Frequency:
Power Consumption:
Integral Design™ Amplifier
Output :
(both channels operating )
Harmonic Distortion:
(THD) @ 250 watts
IM Distortion:
(4:1 60-7kHz) 150 watts
Frequency Response:
Signal to Noise Ratio: (unweighted)
Load Impedance:
Input Sensitivity:
Input Impedance:
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)
82 lbs
95 lbs (shipping)
80 lbs
91 lbs (shipping)
105-125 AC USA, 210-250 AC EUR
50-60 Hz
Minimum 60 watts
Normal 1000 watts
Maximum 1960 watts
250/250 watts @8 ohms
400/400 watts @4 ohms
Less Than .15% (20Hz-5kHz)
Less Than .5% (5kHz-10kHz)
Less Than .15%
20Hz-10kHz ±.25dB
10kHz-15kHz ±.7dB 15kHz-20kHz ±1dB
-100dB ≤.5mV across 8Ω at zero volume
4 ohms or higher
1.5 Vrms for 250 watts output into 8 ohms
50,000 ohms or higher
2
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.Leakage Current Hot Check-With the unit completely reassembled, plug the AC line cord directly into a 120V AC outlet. (Do not use an isolation transformer during this test.) Use a leakage current tester or a metering system that complies with American National Standards Institute (ANSI) C101.1 “Leakage Current for Appliances” and Underwriters Laboratories (UL) 1492 (71). With the unit AC switch first in the ON position, then in the OFF position, measure from a known earth ground (metal water pipe, conduit, etc.) to all exposed metal parts of the unit (antennas, handle bracket, metal cabinet, screwheads, metallic overlays, control shafts, etc.), especially any exposed metal parts that offer an electrical return path to the chassis. Any current measured must not exceed 0.5 milliamp. Reverse the unit power cord plug in the outlet and repeat test. ANY MEASUREMENTS NOT WITHIN THE LIMITS SPECIFIED HEREIN INDICATE A POTENTIAL SHOCK HAZARD THAT MUST BE ELIMINATED BEFORE RETURNING THE UNIT TO THE CUSTOMER.
B.Insulation Resistance Test Cold Check-(1) Unplug the power supply and connect a jumper wire between the two prongs of the plug. (2) Turn on the power switch of the unit. (3) Measure the resistance with an ohmmeter between the jumpered AC plug and each exposed metallic cabinet part on the unit. When the exposed metallic part has a return path to the chassis, the reading should be between 1 and 5.2 Megohms. When there is no return path to the chassis, the reading must be “infinite”. If it is not within the limits specified, there is the possibility of a shock hazard, and the unit must be repaired and rechecked before it is returned to the customer.
3
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.
•Transport or store ESDS devices in ESD protective bags, bins, or totes. Do not insert unprotected devices into materials such as plastic, polystyrene foam, clear plastic bags, bubble wrap or plastic trays.
General Description
The 1801 and 1800 are Integral Design™ Power Amplifiers with all Silicon Solid-State Circuitry using 14 power transistors per channel. Capable of complete stability with all loudspeaker loads regardless of capacitive or inductive character. They employ fast acting electronic protection circuits for current limiting. They use computer grade capacitors throughout the power supply, along with a 2.0kW power transformer and 1300 sq. inches of heat sink area. They also have a power monitor display using a light emitting diode array and in the case of the 1801 signal meters as well.
CAUTION: THE BOSE® 1801/1800 POWER AMPLIFIERS CONTAIN NO USER-SERVICE- ABLE PARTS. TO PREVENT WARRANTY INFRACTIONS, REFER SERVICE TO WARRANTY SERVICE STATIONS OR FACTORY SERVICE.
4
DISASSEMBLY/ASSEMBLY PROCEDURES
1801 Power Amplifier
Note: Refer to Figure 1 for the following procedures.
1.Top Cover Removal
1.1Remove 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.
1.2Slide the top cover towards the rear of the unit and lift the cover off the unit.
2.Top Cover Replacement
2.1Slide the top cover onto the unit while making sure the screws on the side of the unit are lining up with the slots in the top cover.
2.2Secure the top cover to the unit.
3.Amplifier PCB Removal
3.1Perform procedure 1.
3.2Disconnect the wire harness, the two wires connected to the thermal cutout, and the input cable going to the PCB.
3.3Remove the six screws (2B) located on the side of the unit between the heat sink fins (see Figure 2).
3.4Carefully pry the PCB inward towards the power transformer (the PCB is stuck to the chassis by the heat sinking compound) and lift the board out of the unit.
4.Amplifier PCB Replacement
4.1Slide the PCB into place. Be sure there is sufficient heat sink compound on the PCB's heat sink.
4.2Align the six screws that secure the PCB into place and secure the PCB to the chassis.
4.3Connect the wire harness, thermal cutout wires, and the input cable to the PCB.
5.Front Panel Removal
5.1Perform procedure 1.
5.2Remove the nut securing the top of the front panel. The nut is located on the inside of the front chassis beside the thermal cutout indicator.
5.3Remove the knobs on the controls and remove the two shaft nuts holding the front panel in place.
6.Front Panel Replacement
6.1Align the front panel over the controls and secure it in place.
6.2Secure the top of the front panel and replace the knobs.
6.3Perform procedure 2.
7.Front Chassis Assembly Removal
7.1Perform procedure 5.
7.2Locate and remove the four screws that secure the front assembly to the chassis.
7.3Push down on the top of the front assembly to release the bottom of the assembly and pull the assembly towards you.
8.Front Chassis Assembly Replacement
8.1While pushing down on the front assembly slide the assembly in towards the unit.
8.2Pull up on the front assembly to align the screw holes with the unit and secure the assembly in place.
8.3 Perform procedure 6.
5
DISASSEMBLY/ASSEMBLY PROCEDURES
1801 Power Amplifier
Note: Refer to Figure 5 for the following procedures.
9.LED PCB Removal
9.1Perform procedure 7.
9.2Unsolder the wires to the LED PCB and make a note of the wiring configuration.
9.3Remove the center nut located on each side on the LED lamp housing.
9.4Lift the LED assembly out from the front chassis.
9.5Disassemble the LED assembly to gain access to the PCB.
Note: Remember how the lamp housing spacers are placed.
10.LED PCB Replacement
10.1After reassembling the LED assembly, place it onto the front panel assembly and secure it in place.
10.2Resolder the wires to the PCB.
10.3Perform procedure 8.
11.Meter Assembly Removal
11.1Perform procedure 7.
11.2Remove the three nuts holding the meter lamp housing assembly to the front panel assembly.
11.3Remove the two nuts holding the wires to the meter you want to replace and remove the meter.
12.Meter Assembly Replacement
12.1Place the new meter on to the front assembly. Connect the wires going to the
meter.
12.2Place the meter lamp housing over the meters and secure it to the front assembly.
12.3Perform procedure 8.
13.Front Panel Controls Removal
13.1Perform procedure 7.
13.2Locate the control or switch you want to replace and unsolder the wires and components on that control or switch.
13.3Remove the shaft nut holding the control or switch to the front assembly and remove it.
14.Front Panel Controls Replacement
14.1Place the new control or switch into the front assembly and secure it in place.
14.2Resolder the wires and/ or components to the control or switch.
14.3Perform procedure 8.
15.Lamp Removal
15.1Perform procedure 7.
15.2Using a flat blade screwdriver, pry under the edge of the socket and lift the socket out.
16.Lamp Replacement
16.1Replace the defective lamp.
16.2Place the lamp socket back into the lamp housing.
16.3Perform procedure 8.
Note: It may be necessary to remove the LED PCB Assembly to replace the lamps see procedure 9.
6
DISASSEMBLY/ASSEMBLY PROCEDURES
1800 Power Amplifier
Note: Refer to Figure 1 for the following procedures.
1.Top Cover Removal
1.1Remove the four screws that secure the top cover to the unit.
1.2Slide the top cover towards the back of the unit and lift it off.
2.Top Cover Replacement
2.1Place the top cover on to the unit and slide it under the front panel lip.
2.2Secure the top cover to the unit.
3.Amplifier PCB Removal
3.1Perform procedure 1.
3.2Disconnect the wire harness, input cable, and the two wires going to the thermal cutout.
3.3Remove the six screws (2B) located on the side of the unit between the heat sink fins (see Figure 2).
3.4Carefully pry the PCB inward towards the power transformer (the PCB is stuck to the chassis by the heat sinking compound) and lift the board out of the unit.
4.Amplifier PCB Replacement
4.1Slide the PCB into place. Be sure there is sufficient heat sinking compound on the PCB's heat sink.
4.2Align the six screws that secure the PCB into place and secure the PCB to the chassis.
4.3Connect the wire harness, thermal cutout wires, and the input cable to the PCB.
5.Front Panel Removal
5.1Perform procedure 1.
5.2Locate 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.
5.3Using the handles pull the front panel away from the chassis enough to access the gain controls and LED PCB.
6.Front Panel Replacement
6.1Slide the front panel into place. Be careful not to pinch the wiring harness at the bottom of the front panel between it and the chassis.
6.2Align the holes in the front panel with the chassis, place the screws into their location by hand and then tighten with a screwdriver.
Note: While tightening the screws lift up on the top lip of the panel to provide enough room to slide the top cover under the lip.
7.LED PCB Removal
7.1Perform procedure 5.
7.2Remove the two screws that secure the PCB to the front panel.
7.3Unsolder the wires at the LED PCB, make a note of the wiring configuration, and remove the board from the unit.
8.LED PCB Replacement
8.1Place the LED PCB into place on the front panel.
8.2Secure the PCB to the front panel.
8.3Resolder the wires to the LED PCB.
7
DISASSEMBLY/ASSEMBLY PROCEDURES
1800 Power Amplifier
Note: Refer to Figures 3, and 4 for the following procedures.
9.Gain Control Removal
9.1Perform procedure 5.
9.2Remove the gain control knobs.
9.3Unsolder the capacitor lead and wires from the control.
9.4Remove the nut that secures the control to the front panel and remove the control.
10.Gain Control Replacement
10.1Place the new control into the front panel and secure it into place.
10.2Resolder the capacitor lead and the wires to the terminals on the gain control.
10.3Perform procedure 6.
11.Power Switch Removal
11.1Perform procedure 5.
11.2Remove the wires on the rear of the power switch.
11.3Remove the nut securing the switch to the front panel and remove the switch.
12.Power Switch Replacement
12.1Place the new power switch into the front panel and secure it in place.
12.2Reconnect the wires on the rear of the switch.
Note: Refer to Figure 6 for the following procedures.
13.Rear Panel Removal
13.1Perform procedure 1.
13.2Locate 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. Take care not to lose the nuts that secure this screw and the wires.
14.Rear Panel Replacement
14.1Align the rear panel with the chassis.
14.2Secure the rear panel to the chassis. Be sure to use the rear panel bracket on the bottom of the panel.
14.3Secure the ground wires to the chassis.
14.4Perform procedure 2.
12.3 Perform procedure 6.
8
TEST PROCEDURES
1.Bias Adjustment Setup and Procedure
1.1Locate the -85V negative terminal found on the capacitor (C4). See Figure 1 for the location of C4.
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. Either way the lug with the two or three wires is the lug to disconnect from the capacitor. All other lugs remain.
1.2Remove the lug with two or three wires connected to it.
1.3Connect a 0-200mA meter between the disconnected lug and the - terminal on the capacitor C4.
1.4Disconnect the PCB that is not being tested by unplugging the multiple pin connector.
1.5Turn the amplifier on with no input signal applied and adjust the bias pot (R13) for 90mA with the board cold.
Note: The PCB must be removed from the chassis for the bias to be adjusted.
2.Frequency Response Procedure
2.1Apply a 1Vrms, 1kHz signal to the input.
2.2Reference a dB meter to the output.
2.3Check the response from 20Hz to 20kHz. The response should not exceed ±1 dB. Refer to the response specification on page 2.
3.DC Offset Procedure
3.1With no signal applied measure the DC offset at the output. It should measure 250mV or less.
4.Power Output Procedure
4.1Connect an 8 ohm, 250 Watt load to the output.
4.2Apply a 1.75Vrms, 1kHz signal to the input.
4.3Turn the gain controls up to the point where the clipping LED's just begin to light up and check the output for 250 watts.
4.4Repeat the steps above for a 4 ohm load. The output measurement should be 400 watts.
5.Harmonic Distortion Procedure
5.1With the unit connected as in procedure 3, turn the gains up to just before clipping and check the distortion at the frequencies of 20Hz, 5kHz, and 10kHz.
5.2The distortion limits are ≤.15% from 20Hz to 5kHz and ≤.5% from 5kHz to 10kHz.
6.Thermal Cutoff Procedure
6.1Apply a signal to the unit with the outputs loaded ( 8 or 4 ohms ). Short one channel at a time until the unit goes into thermal cutoff. The thermal indicator should turn on and the output of the unit should be off.
6.2Disconnect the short from the output. Wait until the unit comes out of thermal cutoff. You can speed this process by cooling the PCB with a fan.
6.3Once the unit is cooled apply a signal to the channel you had shorted to check to see if its operational.
6.4Apply a signal to the other channel and short the output. Wait for the thermal indicator to come on then remove the short and cool the PCB.
9
Figure 1. 1801 Component Location
Figure 2. 1801 Side View
10
Loading...