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Power Base-2 & 800CSL Amplifier Service Manual
POWER AMPLIFIER
SERVICE MANUAL
® ™
POWER BASE-2 & 800CSL
©1995 by CROWN INTERNATIONAL, INC.
Mailing Address: Shipping Address:
P.O. Box 1000 57620 C.R. 105
Elkhart, IN U.S.A. 46515-1000 Elkhart, IN U.S.A. 46517
™ ® ® ®
CSL is a trademark and Power Base-2, ODEP, and Crown are registered trademarks of Crown International, Inc.
K-SVCPB2
1-95
1
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Power Base-2 & 800CSL Amplifier Service Manual The information furnished in this manual does not include all of the details of design, production, or variations of the equipment. Nor does it cover every possible situation which may arise during installation, operation or maintenance. If you need special assistance beyond the scope of this manual, please contact the Crown Technical Support Group. Mail: P.O. Box 1000 Elkhart IN 46515-1000 Shipping: 57620 C.R. 105 Elkhart IN 46517 Phone: (
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Power Base-2 & 800CSL Amplifier Service Manual Table of Contents Introduction ............................................................. 4 Scope ...................................................................... 4 Warranty .................................................................. 4 Parts ........................................................................ 5 Specifications .......................................................... 6 Voltage Conversion .........................
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Power Base-2 & 800CSL Amplifier Service Manual Introduction This manual contains service information on Crown Each of the compact audio power amplifiers are power amplifiers. It is designed to be used in conjunc- designed for professional or commercial use. Provid- tion with the applicable Owner's Manual. However, ing high power amplification from 20Hz to 20KHz with some important information is duplicated in this Ser- minimum distortion, they feature balanced inputs with vice Manual in case t
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Power Base-2 & 800CSL Amplifier Service Manual Parts shipment on a C.O.D. or pre-payment (check or credit GENERAL INFORMATION card) basis. Later sections include both mechanical and electrical parts lists for this product. The parts listed are current TERMS as of the date printed. Crown reserves the right to modify and improve its products for the benefit of its Normal terms are pre-paid. Net-30 Days applies to customers. only those firms having pre-established accounts with Crown. If pre-paying
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Power Base-2 & 800CSL Amplifier Service Manual Specifications Unless noted otherwise, all specifications are based Input Impedance: Nominally 20K ohms balanced; 10K on driving an 8 ohm load per channel, both channels ohms unbalanced. driven, the sensitivity switch in the 26dB position, the AC supply is 120VAC at 60Hz. Crown specifications Output Impedance: <10 milliohms in series with <2 are guaranteed through the warranty period (normally microhenries. 3 years). Because our testing methods are
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Power Base-2 & 800CSL Amplifier Service Manual Voltage Conversion PB/CSL Universal Fuse Board P16 P6 P10 100V Connections: P15 P5 P10 to P15 P11 to P14 P7 to P12 P14 P4 120V Connections: P9 P10 to P16 P11 to P14 P8 P7 to P13 P13 P3 220V Connections: P7 P10 to P15 P12 P2 P9 to P14 P8 to P13 P19 BLU 240V Connections: P11 P1 P10 to P16 P20 BRN P9 to P14 P8 to P13 For list of applicable transformer, fuse F100, fanformer, and power P22 cord refer to voltage- parts cross-reference. F100 F1 P21 P18 P17
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Power Base-2 & 800CSL Amplifier Service Manual Theory clude a single core transformer (one primary with two OVERVIEW independent ungrounded secondaries), a full time full It should be noted from the outset that the PB-1 and speed fan which also serves as the low voltage 460CSL amplifiers are electrically and mechanically transformer, slew rate limiting, and audio muting for identical products. The only differences, from a ser- delay or protective action. This amplifier can operate vice perspecti
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Power Base-2 & 800CSL Amplifier Service Manual Theory tivity is achieved by controlling the ratio of feedback to Voltage Translators input resistance. The Sensitivity Switch sets the input A voltage divider network splits the Error Signal (ES) impedance to this stage and varies the gain such that into positive and negative drive signals for the bal- the overall amplifier gain is 26 dB, or is adjusted anced voltage translator stage. These offset reference appropriately for 0.775V or 1.4V input to
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Power Base-2 & 800CSL Amplifier Service Manual Theory allows the NFb loop to control Error Amp gain by The output of the +LVA drives the base of predriver feeding back to its non-inverting input (with its polarity device. Together, the predriver and driver form the opposite to the output of the VGS). With the added first two parts of the three-deep Darlington and are voltage swing provided by the LVAs, the signal then biased class AB. They provide output drive through gains current amplification
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Power Base-2 & 800CSL Amplifier Service Manual Theory the positive half, and about .5V across the bias resistor a negative polarity. Using the same example as above, in the negative half. Q18 conduction (and thus bias) is a 70V supply would allow a negative output peak of - adjustable. 70V. In summary, a power supply which produces a total of 70VDC rail to rail (or ±35VDC statically) is A diode string prevents excessive charge build up capable of producing 140V peak-to-peak at the ampli- within
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Power Base-2 & 800CSL Amplifier Service Manual Theory ±ODEP circuitry is used to simulate the thermal barri- ers between the interior of the output device die (immeasurable by normal means) and the time delay from heat generation at the die until heat dissipates to the thermal sensor. The combined effects of thermal history and instantaneous dynamic power level result in an accurate simulation of the actual thermal condi- tion of the output transistors. POSITIVE +VOLTAGE +LVA HIGH SIDE -1 TRANSL
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Power Base-2 & 800CSL Amplifier Service Manual Checkout Procedures GENERAL INFORMATION TEST 3: ODEP VOLTAGE ADJUSTMENT The following test procedures are to be used to verify Spec: Cold Bias Per Charts Below ±0.1V DC. operation of this amplifier. DO NOT connect a load or Initial Conditions: Controls per standard, heatsink at inject a signal unless directed to do so by the proce- room temperature 20 to 30°C (68 to 86°F). Note: This dure. These tests, though meant for verification and adjustment sh
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Power Base-2 & 800CSL Amplifier Service Manual Checkout Procedures Procedure: No Load. Inject a 1 kHz sine wave. With TEST 4: AC POWER DRAW level controls fully clockwise you should see full gain. Spec: 90 Watts maximum quiescent. As controls are rotated counterclockwise, observe Initial Conditions: Controls per standard. similar gain reduction in each channel. When com- Procedure: With no input signal and no load, measure plete, return level controls to fully clockwise position. AC line wattage
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Power Base-2 & 800CSL Amplifier Service Manual Checkout Procedures Procedure Capacitive: Load each channel to 8 ohms in TEST 15: LF PROTECTION parallel with 2 µF. Inject a 20 kHz sine wave with 30 Spec: Amplifier mutes for low frequency. VAC output for 10 seconds. Initial Conditions: Controls per standard. Procedure Inductive: Load each channel to 8 ohms in Procedure: No load. Inject a 0.5 Hz 6 volt peak-to-peak parallel with 159 µHenries. Inject a 1 kHz sine wave square wave into each channel a
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Power Base-2 & 800CSL Amplifier Service Manual Checkout Procedures POST TESTING After completion of testing, if all tests are satisfactory, the amplifier controls should be returned to the posi- tions required by customer. If conditions are unknown or unspecified, factory settings are as follows: Level Controls: 9 to 11 O’Clock. Sensitivity Switch: 0.775V U.S., 1.4V International. Stereo/Mono Switch: Stereo. Ground Lift: Lift. Power: Off. 16
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Power Base-2 & 800CSL Amplifier Service Manual Mechanical (Non-Module) Parts SUPPLIMENTAL ITEMS CPN ITEM QTY D 4137-2 Nylon Thumbscrew Washer 4 C 3342-0 Feet, Black Self-Stick 4 A10087-71012 10-32 .75 Machine (Rack Screw) 4 120VAC/60HZ NORTH AMERICA PRODUCT ONLY CPN ITEM QTY A10089-10832 Screw, 8-32 2.0 Ph Machine 4 A10285-28 Fuse, 20A 3AB (120V Units) 1 A10285-7 Fuse, .5A AGC 1.25x.25 (LVPS) 1 D 6748-4 PB-2 Power Transformer 1 A10089-10832 Screw, 8-32 2.0 Ph Mach 4 A10101-19 Washer, Fiber (XFMR
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Power Base-2 & 800CSL Amplifier Service Manual Mechanical (Non-Module) Parts OUTPUT ASSEMBLY (ONE PER CHANNEL) CPN ITEM QTY A10100-4 Washer, #6 Flat Zinc 2 A10315-1 Screw, 6-32-.56 Hex Washer Head 12 C 4751-1 NPN Output Device 4 C 5826-0 S100/S200 Thermal Sense LM334Z 1 C 6492-0 PNP Output Device 4 C 7326-9 Solder Lug, #6 Tin 2 C 8573-5 PNP Driver Device TO-3P 2 C 8574-3 NPN Driver Device TO-3P 2 C 8813-5 Q318/Q418 Bias Servo MPSA18/MPS8097 1 C 9327-9 Rivet, Plastic 2 C 9491-9 Screw, 6-32-.312 T
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Power Base-2 & 800CSL Amplifier Service Manual Mechanical (Non-Module) Parts MAIN CHASSIS ASSEMBLY CPN ITEM QTY A10086-70806 Screw, 8-32-.37 Mach Rd Ph 2 A10094-3 Washer, #6 Black Star 3 A10094-6 Washer, #8 Black Star 4 A10094-8 Washer, #10 Tooth Lock 10 A10099-5 Washer, #8 Nylon Shoulder 4 A10109-10822 Screw, 8-18-1.375 Pan Ph 2 A10110-70812 Screw, 8-32-.75 Taptite Pan Ph 2 A10192-1 Snap Bushing .5 4 C 1811-6 Tie Wrap 4 C 3163-0 Solder Lug #6 505 1 C 6487-0 Power Switch 22A Rocker 2 Pole 1 C 69
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Power Base-2 & 800CSL Amplifier Service Manual Module Information MODULE HISTORY MAIN MODULES: Since its introduction in 1986, the PB-1 has gone Q42665-2 through a number of updates and revisions. Over the Original Main Module for PB-2. No longer available. course of its history some of these changes have Q42683-5 resulted in upgrading to newer modules. What follows Main #2 for PB-2. No longer available. is a historical breakdown of PB-1 modules. It should Q42818-7 also be noted that the 460CSL
