Crown POWER BASE 1, POWER BASE 2, POWER BASE 3 User Manual

™

POWER

OFF

POWER

OFF

POWER

OFF

E106377

®

Applies only to 120 VAC, North American PB-1, PB-2 and PB-3 units.

Models:

Power Base-1, 2 & 3

© 1996 by Crown International, Inc., P.O. Box 1000, Elkhart, Indiana 46515-1000 U.S.A. Telephone: [phone]. Power-Tech amplifiers are produced by the Professional Audio Division of Crown International, Inc. Trademark Notice: Power Base-3™ is a trademark and Power Base-1®, Power Base-2 ®, Crown,® IOC ® and ODEP ® are registered trademarks of Crown International, Inc. Other trademarks are the property of their respective owners.

LL 32521C

®

Applies only to 120 VAC, North American PB-1 and PB-2 units.

101229-1 12/96

3 YEAR

THREE YEAR

FULL WARRANTY

3 YEAR

WORLDWIDE

NORTH AMERICA

SUMMARY OF WARRANTY

The Crown Audio Division of Crown International, Inc., 1718 West Mishawaka Road, Elkhart, Indiana 46517-4095 U.S.A. warrants to you, the ORIGINAL PURCHASER and ANY SUBSEQUENT OWNER of each NEW Crown1 product, for a period of three (3) years from the date of purchase by the original purchaser (the “warranty period”) that the new Crown product is free of defects in materials and workmanship, and we further warrant the new Crown product regardless of the reason for failure, except as excluded in this Crown Warranty.

1 Note: If your unit bears the name “Amcron,” please substitute it for the name “Crown” in this warranty.

ITEMS EXCLUDED FROM THIS CROWN WARRANTY

This Crown Warranty is in effect only for failure of a new Crown product which occurred within the Warranty Period. It does not cover any product which has been damaged because of any intentional misuse, accident, negligence, or loss which is covered under any of your insurance contracts. This Crown Warranty also does not extend to the new Crown product if the serial number has been defaced, altered, or removed.

WHAT THE WARRANTOR WILL DO

We will remedy any defect, regardless of the reason for failure (except as excluded), by repair, replacement, or refund. We may not elect refund unless you agree, or unless we are unable to provide replacement, and repair is not practical or cannot be timely made. If a refund is elected, then you must make the defective or malfunctioning product available to us free and clear of all liens or other encumbrances. The refund will be equal to the actual purchase price, not including interest, insurance, closing costs, and other finance charges less a reasonable depreciation on the product from the date of original purchase. Warranty work can only be performed at our authorized service centers. We will remedy the defect and ship the product from the service center within a reasonable time after receipt of the defective product at our authorized service center. All expenses in remedying the defect, including surface shipping costs to the nearest authorized service center, will be borne by us. (You must bear the expense of all taxes, duties and other customs fees when transporting the product.)

HOW TO OBTAIN WARRANTY SERVICE

You must notify us of your need for warranty service not later than ninety (90) days after expiration of the warranty period. All components must be shipped in a factory pack. Corrective action will be taken within a reasonable time of the date of receipt of the defective product by our authorized service center. If the repairs made by our authorized service center are not satisfactory, notify our authorized service center immediately.

DISCLAIMER OF CONSEQUENTIAL AND INCIDENTAL DAMAGES

YOU ARE NOT ENTITLED TO RECOVER FROM US ANY INCIDENTAL DAMAGES RESULTING FROM ANY DEFECT IN THE NEW CROWN PRODUCT. THIS INCLUDES ANY DAMAGE TO ANOTHER PRODUCT OR PRODUCTS RESULTING FROM SUCH A DEFECT.

WARRANTY ALTERATIONS

No person has the authority to enlarge, amend, or modify this Crown Warranty. This Crown Warranty is not extended by the length of time which you are deprived of the use of the new Crown product. Repairs and replacement parts provided under the terms of this Crown Warranty shall carry only the unexpired portion of this Crown Warranty.

DESIGN CHANGES

We reserve the right to change the design of any product from time to time without notice and with no obligation to make corresponding changes in products previously manufactured.

LEGAL REMEDIES OF PURCHASER

No action to enforce this Crown Warranty shall be commenced later than ninety (90) days after expiration of the warranty period.

THIS STATEMENT OF WARRANTY SUPERSEDES ANY OTHERS CONTAINED IN THIS MANUAL FOR CROWN PRODUCTS.

9/90

Telephone: [phone]. Facsimile: 219-294-8301

SUMMARY OF WARRANTY

The Crown Audio Division of Crown International, Inc., 1718 West Mishawaka Road, Elkhart, Indiana 46517-4095 U.S.A. warrants to you, the ORIGINAL PURCHASER and ANY SUBSEQUENT OWNER of each NEW Crown product, for a period of three (3) years from the date of purchase by the original purchaser (the “warranty period”) that the new Crown product is free of defects in materials and workmanship. We further warrant the new Crown product regardless of the reason for failure, except as excluded in this Warranty.

ITEMS EXCLUDED FROM THIS CROWN WARRANTY

This Crown Warranty is in effect only for failure of a new Crown product which occurred within the Warranty Period. It does not cover any product which has been damaged because of any intentional misuse, accident, negligence, or loss which is covered under any of your insurance contracts. This Crown Warranty also does not extend to the new Crown product if the serial number has been defaced, altered, or removed.

WHAT THE WARRANTOR WILL DO

We will remedy any defect, regardless of the reason for failure (except as excluded), by repair, replacement, or refund. We may not elect refund unless you agree, or unless we are unable to provide replacement, and repair is not practical or cannot be timely made. If a refund is elected, then you must make the defective or malfunctioning product available to us free and clear of all liens or other encumbrances. The refund will be equal to the actual purchase price, not including interest, insurance, closing costs, and other finance charges less a reasonable depreciation on the product from the date of original purchase. Warranty work can only be performed at our authorized service centers or at the factory. We will remedy the defect and ship the product from the service center or our factory within a reasonable time after receipt of the defective product at our authorized service center or our factory. All expenses in remedying the defect, including surface shipping costs in the United States, will be borne by us. (You must bear the expense of shipping the product between any foreign country and the port of entry in the United States and all taxes, duties, and other customs fees for such foreign shipments.)

HOW TO OBTAIN WARRANTY SERVICE

You must notify us of your need for warranty service not later than ninety (90) days after expiration of the warranty period. All components must be shipped in a factory pack, which, if needed, may be obtained from us free of charge. Corrective action will be taken within a reasonable time of the date of receipt of the defective product by us or our authorized service center. If the repairs made by us or our authorized service center are not satisfactory, notify us or our authorized service center immediately.

DISCLAIMER OF CONSEQUENTIAL AND INCIDENTAL DAMAGES

YOU ARE NOT ENTITLED TO RECOVER FROM US ANY INCIDENTAL DAMAGES RESULTING FROM ANY DEFECT IN THE NEW CROWN PRODUCT. THIS INCLUDES ANY DAMAGE TO ANOTHER PRODUCT OR PRODUCTS RESULTING FROM SUCH A DEFECT. SOME STATES DO

NOT ALLOW THE EXCLUSION OR LIMITATIONS OF INCIDENTAL OR CONSEQUENTIAL DAMAGES, SO THE ABOVE LIMITATION OR EXCLUSION MAY NOT APPLY TO YOU.

WARRANTY ALTERATIONS

No person has the authority to enlarge, amend, or modify this Crown Warranty. This Crown Warranty is not extended by the length of time which you are deprived of the use of the new Crown product. Repairs and replacement parts provided under the terms of this Crown Warranty shall carry only the unexpired portion of this Crown Warranty.

DESIGN CHANGES

We reserve the right to change the design of any product from time to time without notice and with no obligation to make corresponding changes in products previously manufactured.

LEGAL REMEDIES OF PURCHASER

THIS CROWN WARRANTY GIVES YOU SPECIFIC LEGAL RIGHTS, YOU MAY ALSO HAVE OTHER RIGHTS WHICH VARY FROM STATE TO STATE. No action to enforce this Crown Warranty shall be commenced later than ninety (90) days after expiration of the warranty period.

THIS STATEMENT OF WARRANTY SUPERSEDES ANY OTHERS CONTAINED IN THIS MANUAL FOR CROWN PRODUCTS.

Telephone: [phone]. Facsimile: 219-294-8301

9/90

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 our Technical Support Group.

Crown Audio Division Technical Support Group

Plant 2 SW, 1718 W. Mishawaka Rd., Elkhart, Indiana 46517 U.S.A.

Phone: [phone] (North America, Puerto Rico and Virgin Islands) or 219-294-8200 Fax: [phone] Fax Back: 800-294-4094 (North America only) or 219-293-9200 Internet: http://www.crownintl.com

IMPORTANT

THE POWER BASE-3 REQUIRES CLASS 1 OUTPUT WIRING. THE POWER BASE-1 AND 2 REQUIRE CLASS 2 OUTPUT WIRING.

		C A U T I O N			A V I S
		RISK OF ELECTRIC SHOCK			RISQUE DE CHOC ÉLECTRIQUE
		DO NOT OPEN			N’OUVREZ PAS
	TO PREVENT ELECTRIC SHOCK DO			À PRÉVENIR LE CHOC ÉLECTRIQUE
	NOT REMOVE TOP OR BOTTOM			N’ENLEVEZ PAS LES COUVERCLES. IL
	COVERS. NO USER SERVICEABLE			N’Y A PAS DES PARTIES SERVICEABLE
	PARTS INSIDE. REFER SERVICING TO			À L’INTÉRIEUR. TOUS REPARATIONS
	QUALIFIED SERVICE PERSONNEL.			DOIT ETRE FAIRE PAR PERSONNEL
	DISCONNECT POWER CORD BE-			QUALIFIÉ SEULMENT. DÉBRANCHER
	FORE REMOVING BACK PANEL			LA BORNE AVANT D’ENLEVER LA
	COVER TO ACCESS GAIN SWITCH.			COVERTURE EN ARRIÈRE.

WARNING

TO REDUCE THE RISK OF ELECTRIC SHOCK, DO NOT EXPOSE THIS EQUIPMENT TO RAIN OR MOISTURE!

Magnetic Field

CAUTION! Do not locate sensitive high-gain equipment such as preamplifiers or tape decks directly above or below the unit. Because this amplifier has a high power density, it has a strong magnetic field which can induce hum into unshielded devices that are located nearby. The field is strongest just above and below the unit.

If an equipment rack is used, we recommend locating the amplifier(s) in the bottom of the rack and the preamplifier or other sensitive equipment at the top.

The lightning bolt triangle is used to alert the user to the risk of electric shock.

The exclamation point triangle is used to alert the user to important operating or maintenance instructions.

Printed on recycled paper.

Power Base Series Power Amplifiers

			CONTENTS
1	Welcome ..........................................................................			7
	1.1	Unpacking .................................................................		7
	1.2	Features ....................................................................		7
2	Installation .......................................................................			9
	2.1	Stereo	........................................................................	9
	2.2	Mono .........................................................................		9
	2.3	Input Sensitivity Adjustment......................................		10
	2.4	Additional Load Protection .......................................		10
	2.5	Required AC Mains ..................................................		10
3	Operation .......................................................................			11
	3.1	Precautions ..............................................................		11
	3.2	Power Indicator ........................................................		11
	3.3	Protection Systems...................................................		11
		3.3.1	ODEP ............................................................	11
		3.3.2 Ultrasonic and RF Protection ..........................		11
		3.3.3	Drive Protection .............................................	11
		3.3.4	Transformer Thermal Protection .....................	12
		3.3.5 Fuses and Circuit Breakers ............................		12
	3.4	Controls ...................................................................		12
	3.5	Filter Cleaning ..........................................................		12
4	Specifications ................................................................			13
5	Accessories ...................................................................			19
	5.1	MT-XLR ....................................................................		19
	5.2	MT-BB .....................................................................		19
6	Service ...........................................................................			20
	6.1	Worldwide Service ...................................................		20
	6.2	North American Service ...........................................		20
		6.2.1 Service at a North American Service Center ...		20
		6.2.2	Factory Service ..............................................	20

Page 4

Power Base Series Power Amplifiers

ILLUSTRATIONS
1.1 Power Base Front and Back Panels ....................................	7
2.1Three System Connection Methods .......................................	8
2.2Do NOT Block Air Flow ..........................................................	9
2.3Power Base Input Wiring .......................................................	9
2.4Input Sensitivity Switch ........................................................	10
2.5Loudspeaker Fuse Nomograph ...........................................	10
3.1Back Panel Level Controls ...................................................	12
4.1Power Base-1 Minimum Power Matrix ..................................	15
4.2Power Base-2 Minimum Power Matrix ..................................	16
4.3Power Base-3 Minimum Power Matrix ..................................	16
4.4Power Base-1 Maximum Power Matrix .................................	17
4.5Power Base-2 Maximum Power Matrix .................................	18
4.6Power Base-3 Maximum Power Matrix .................................	18
5.1The MT-XLR ........................................................................	19
5.2The MT-BB ..........................................................................	19

Page 5

Power Base Series Power Amplifiers

Page 6

Power Base Series Power Amplifiers

Power Power

Indicator Switch

POWER

OFF

					5-Way Binding Post
Reset	Power	Access	Removable grille
Switch	Cord	Cover	and dust filter		Output Connectors

(Power Base–3 Only)

MODEL: POWER-BASE™ 3 12.5 AMPS		PUSH TO RESET
AC VOLTS: 120	60 Hz
MAXIMUM OUTPUT: 700 WATTS		S	TE
PER CHANNEL INTO 4 OHMS AT 1 KHz			S
WITH NO MORE THAN 0.1% THD.		ES	E
		R
		P	R
	® INTERNATIONAL, INC.
ELECTRONIC EQUIPMENT
ELKHART, IN 46517	0000
MADE IN U.S.A.
SERIAL NUMBER	000000

WARNING: TO

REDUCE THE RISK OF			STEREO
FIRE OR ELECTRIC		PARALLEL				BRIDGE
SHOCK, DO NOT EXPOSE
THIS EQUIPMENT TO		MONO				MONO
RAIN OR MOISTURE.	REG. U.S. PAT. OFF.	CAUTION: TURN
	4,330,809				OFF AMPLIFIER
	4,611,180	BEFORE CHANGING			THIS SWITCH!

Stereo/Mono

Switch

		CAUTION: TO PREVENT ELECTRIC
CAUTION:		SHOCK DO NOT REMOVE TOP OR BOTTOM
	OUTPUTS	COVERS. NO USER SERVICEABLE PARTS
THIS COVER IS NECESSARY FOR		INSIDE. REFER SERVICING TO QUALIFIED
	CLASS 2	SERVICE PERSONNEL. DISCONNECT POWER
EFFICIENT COOLING OF THE AMPLIFIER.	OUTPUT	CORD BEFORE REMOVING REAR COVER
REMOVE ONLY TO ACCESS GAIN SWITCH.	WIRING	PLATE TO ACCESS SENSITIVITY SWITCH.
	REQUIRED.	ATTENTION: DÉBRANCHER AVANT
		D'OUVRIR.

CH-2 CH-1

	THIS AMPLIFIER IS EQUIPPED WITH SELECTABLE INPUT SENSITIVITY. REMOVE COVER PLATE (ABOVE) TO ACCESS SENSITIVITY SWITCH.											BRIDGE-MONO WIRING		–	PARALLEL-MONO WIRING		+
					CH-2			CH-1
												1	TURN AMPLIFIER OFF.		1	TURN AMPLIFIER OFF.
			6						6
		5		7				5		7		2	SET STEREO/MONO	+	2	SET STEREO/MONO SWITCH	–
		4			8			4		8			SWITCH TO			TO PARALLEL-MONO.
BALANCED		3			9			3		9	UNBALANCED		BRIDGE-MONO.		3	ADD JUMPER (14
		2			10			2		10		3	OUTPUT ACROSS
INPUT WIRING						INPUT GROUND LIFT					INPUT WIRING					GAGE OR LARGER)
	+ TIP	1			11			1		11	+ TIP		RED TERMINALS			ACROSS RED TERMINALS.
		0		12	INPUT	LIFT	INPUT	0		12			ONLY. (CH-1		4	OUTPUT ACROSS CH-1
	– RING	GAIN				(AFFECTS PHONE INPUTS ONLY.)		GAIN					IS POSITIVE.)			TERMINALS ONLY.
GND	SLEEVE						(MONO)				GND SLEEVE

Ch.2	Ch.2	Ground	Ch.1	Ch.1
Level	¼ Inch	Lift	¼ Inch	Level
Control	Phone	Switch	Phone	Control
	Input		Input

Fig. 1.1 Power Base Front and Back Panels

1 Welcome

Congratulations on choosing a Power Base amplifier. Power Base amplifiers are compact, professional stereo power amplifiers engineered to meet the most demanding sound reinforcement needs. They compare very favorably to more expensive amplifiers, providing uncolored sound and signal-to-noise ratios commonly associated with recording studios.

This manual will help you successfully install and use your amplifier—we strongly recommend you read all instructions, warnings and cautions. If you plan to operate in one of the two mono modes, be sure to read Section 2.2. Also for your protection, please save your bill of sale as it is your official proof of purchase.

1.1 Unpacking

Please unpack and inspect your new amplifier for any damage that may have occurred during transit. If damage is found, notify the transportation company immediately. Only you, the consignee, may initiate a claim with the carrier for damage resulting during shipment. Even if the unit arrived in perfect condition, as most do, save all packing materials so you will have them if you ever need to transport the unit. NEVER SHIP THE

UNIT WITHOUT THE FACTORY PACK.

1.2 Features

Rugged, professional power amplifier built for the road. Mounts in a standard 19 inch (48.3 cm) rack.

Crown’s patented grounded bridge circuitry generates large voltage swings while avoiding electrical stress on the output stages. This results in low distortion and high reliability.

Front panel power switch with turn-on delay for loudspeaker protection.

Patented Output Device Emulation Protection (ODEP®) keeps the amplifier working when others would fail.

High damping factor provides superior control over low frequency drivers for a clean, accurate low end.

Safe with any load. Bridge-Mono and Parallel-Mono modes offer optimal load-matching performance.

Complete protection against shorted outputs, mismatched loads, overheating, DC input/output and highfrequency overload; full internal fault protection.

Balanced phone jack inputs with internal three-position sensitivity switch. Optional XLR or barrier block input connectors are available with the MT-XLR or MT-BB accessories.

Ground lift switch is provided to isolate the chassis ground from the phone jack input ground.

Efficient heat sinks and self-contained forced air cooling system dissipate heat quickly and evenly for extra amplifier protection and greater power output.

Three year “No-Fault” full warranty and guaranteed specifications protect your investment.

Page 7