CLEANING/ MAINTENANCE
It may be necessary to use additional adaptors on other grounded components if more than two components are earth grounded. (In other words, only one earth ground per system should exist.) Another potential source of multiple earth grounds is from coaxial antenna or cable service feeds for FM or video sources, which usually are (and should be) earth grounded. The ground adaptor(s) should cure this grounding problem as well.
WARNING: The use of ground adaptors (with the ground tab or wire of the adaptor disconnected) will eliminate the safety feature of the grounded power cord. This safety feature is intended to reduce the risk of electric shock should an internal fault in the equipment result in an electrically “live” chassis. Therefore, this method of ground isolation should be employed only when absolutely necessary, rather than as a general practice. When using a ground adaptor for isolation, make sure that the power cord plug is inserted into the receptacle in the same orientation as if no adaptor were present, to maintain the same hot/neutral polarity.
SPECIAL NOTE ON VIDEO CABLE “GROUNDS”: As mentioned above, the ground conductor of cable service and antenna feeds should be connected to earth ground. Often, however, due to long feed lengths, especially in apartment distribution systems, this ground will be of poor quality and could be a source of noise. This interference is usually characterized by a high frequency noise, rather than a hum or a buzz. If such interference is experienced, a separate earth ground connection should be made from the cable outlet nearest the audio/video equipment to a known good earth ground.
If ground loops exist due to potential differences in the interconnects in rack mounted systems, then it is advisable to isolate the preamplifier chassis from the rack rails. This may be accomplished by sandwiching a thin sheet of insulating material (i.e., plastic washers or several layers of electrical tape, etc.) between the rack and the preamplifier, and securing the unit with
If the faceplate should become soiled, it may be cleaned with a slightly damp, soft cloth and, if necessary, a mild detergent. Do not use any abrasive cleaners or solvents. Unplug the power cord before attempting any cleaning operations.
Except as specifically detailed in the owners manual, there are no user serviceable parts or adjustments inside the 9180/9270 Amplifier, and all servicing should be referred to qualified, authorized personnel.
Parts List
DESIGNATORS | l- 99: | LEFT | CHANNEL | DESIGNATOR | VALUE | PART NUMBER | |
| RIGHT | CHANNEL |
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| 201 | COMMON PARTS | R13,R113 | 2 6 7 | |||
| 301 | CHASSIS/POWER SUPPLY | R14,R114 | 2 6 7 | |||
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| R15,R115 | 1K | |
DESIGNATOR | VALUE | PART | NUMBER | R16,R116 | 1K | ||
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| R17,R117 | 1 0 0 | |
ALL RESISTORS 114 WATT, 1% METAL FILM | R18,R118 | 1 0 0 | |||||
(unless specified | otherwise)) |
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| R19,R119 | 47.5K | ||
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| R20,R120 | 5 6 2 | |
R1,R101 | 2.43K | R21 ,R121 | 4 7 5 | ||||
R2,R102 | 2.43K | R22,R122 | 1 0 | ||||
R3,R103 | 4 7 | . 5 | R23,R123 | 4 7 . 5 | |||
R4,R104 | 4 7 | . 5 | R24,R124 | 4 7 . 5 | |||
R5,R105 | 66.1 | R25,R125 | 2 2 1 | ||||
R6,R106 | 4 7 | . 5 | R26,R126 | 4 7 5 | |||
R7,R107 | 4 7 | . 5 | R27,R127 | 4 7 5 | |||
R8,R108 | 1K |
| R28,R128 | 4 7 5 | |||
R9,R109 | 1K |
| R29,R129 | 221 | |||
R10,R110 | 6.61K | R30,R130 | 2 2 1 | ||||
R11,R111 | 47.5K | R31 ,R131 | 2 2 1 | ||||
R12,R112 | 2.43K | R32,R132 | 4 7 5 K | ||||