Instructions for Use, v 99 - Krell Industries

1 Leader in Audio EngineeringKAV-250aStereo Power AmplifierKAV-250a/3 Three-Channel Power AmplifierInstructions for Use, v s ReferenceKAV-250a Stereo Power Amplifier andKAV-250a/3 Three-Channel Power AmplifierInstructions for Use, v : KAV-250a/3 Three-Channel Power AmplifierKrell Industries , Connair RoadOrange, CT 06477-3650 USATEL 203-799-9954 FAX 203-799-9796E-MAIL Krell @ product complies with the EMC directive (89/336/EEC) and the low-voltage directive(73/23/EEC).WARNINGSThe amplifier must be placed on a firm, level surface where it is not exposed to dripping ventilation grids on the top of the amplifier and the space underneath the amplifier must beunobstructed at all times during operation. Do not place flammable material above or beneaththe your authorized Krell dealer, distributor, or Krell before using any devices designed toalter or stabilize the AC power for the KA V-250a or KA V-250 connecting the KA V-250a or KA V-250a/3, make sure the amplifier is off and any outputdevice (such as a preamplifier) is in mute or stand-by mode.

2 Make sure all cable terminationsare of the highest quality and free from frayed ends, short circuits, or cold solder only one set of inputs to the amplifier at a reconfiguring for MAT, do not use more than one input at the same bridging, do not use both inputs at the same ARE NO USER SERVICEABLE PARTS INSIDE ANY Krell PRODUCTP lease contact your authorized Krell dealer, distributor, or Krell if you have any questions notaddressed in this reference product is manufactured in the United States of America. Krell is a registered trademark of KrellIndustries, Inc., and is restricted for use by Krell Industries , Inc., its subsidiaries, and authorized Amp ThroughputTM is a trademark of Krell Industries , Inc. All other trademarks and tradenames areregistered to their respective companies. 1999 by Krell Industries , Inc. All rights reservedP/N: I960101710688 ContentsINTRODUCTION DEFINITION OF TERMSUNPACKINGPLACEMENTAC Power GuidelinesFRONT PANEL DESCRIPTION: KAV-250aBACK PANEL DESCRIPTION: KAV-250aFRONT PANEL DESCRIPTION: KAV-250a/3 BACK PANEL DESCRIPTION.

3 KAV-250a/3 CONNECTING THE KAV-250a or KAV-250aJ3 AMPLIFIERTO YOUR SYSTEMI nput and Output ConnectionsOPTIONAL SYSTEM CONFIGURATIONSM ulti Amp ThroughputBridged OperationExamples of Connection ScenariosAMPLIFIER OPERATIONOn/Off and OperationAMPLIFIER TROUBLESHOOTINGHow to Troubleshoot System NoiseQUESTION AND ANSWERWARRANTYRETURN AUTHORIZATION PROCEDURESPECIFICATIONSPage1123357101214 14151520222525262627282930 KAV-250a and KAV-250a/3 AmplifiersiiiIllustrationsFIGURE 1 FIGURE 2 FIGURE 3 FIGURE 4 FIGURE 5 The KAV-250a Front PanelThe KAV-250a Back PanelThe KAV-250a/3 Front PanelThe KAV-250a/3 Back PanelReconfiguring the KAV-250a for MATor Bridged OperationFIGURE 6 Reconfiguring the KAV-250a/3 for MATor Bridged OperationPage469111619ivKAV-250a and KAV-250a/3 AmplifiersIntroductionThank you for your purchase of the Krell KAV-250a Stereo Power Amplifier orKAV-250a/3 Three-Channel Power KAV-250a and KAV-250aJ3 amplifiers provide substantial two- and three-channeloutput power that delivers realistic music production at an exceptional value.

4 Theseamplifiers can be customized with a variety of optional system configurations: MultiAmp Throughput (MAT), bridged operation, and high power mono operation. Theseoptions provide a wider range of power outputs and connection options. Both the KAV-250a and KAV-250a/3 amplifiers provide balanced and single-ended inputs forcomplete compatibility with other components. The KAV-250a and KAV-250a/3amplifiers can be operated using the 12 VDC trigger for other components. Eitheramplifier integrates seamlessly home theater or whole-house reference manual contains important information on placement, installation, andoperation of the KAV-250a and KAV-250a/3 amplifiers. Please read this informationcarefully. A thorough understanding of these details helps ensure satisfactory operationand long life for your KAV-250a or KAV-250aJ3 amplifier and related of TermsMulti Amp ThroughputAn internal connection option that sends the same music signal to all amplifier channelsusing one balanced or single-ended connection.

5 MAT reduces installation complexityand cabling requirements in systems containing multiple amplifiers. MAT also allows avariety of connection scenarios, including powering loudspeakers that have two sets ofbinding posts and independently powering multiple pairs of stereo loudspeakers toextend the listening environment throughout your internal connection option that links two amplifier channels to operate as onecombined amplifier channel, greatly increasing the channel s power the power button on the front panel is pressed and the blue power LEDilluminates, the amplifier is on and ready to play the power button on the front panel is pressed and the blue power LED turns off,the amplifier is and KAV-250a/3 Amplifiers1 UnpackingOpen the shipping box, which contains:1 amplifier unit (packed in foam end-caps)2 ribbon connection cablesKAV-250a fuses:2 AGC-8 (~ amp)1 slow-blow (20 amp for 100/120 V or 12 amp for 220/240 V)orKAV-250a/3 fuses.

6 3 ~ amp)1 slow-blow (20 amp for 100/120 V or 12 amp for 220/240 V)1 12 VDC output (12 V trigger) cable1 IEC connector (AC power) cord1 T-15 Torx wrench1 packet containing the owner s reference manual and the warranty the underside of the foam end-caps that encase the amplifier and lift theamplifier straight out of the shipping the amplifier in a safe location and remove the protective plastic any of these items are not included in the shipping box, please contact yourauthorized Krell dealer, distributor, or Krell for all packing materials. If you ship your amplifier in the future, repack the unit in itsoriginal packaging to prevent trans# damage. See Return Authorization Procedure,on page 29, for more and KAV-250aJ3 AmplifiersPlacementBefore you integrate the KAV-250a or KAV-250a/3 into your system, review thefollowing guidelines to choose the location for the component.

7 This will facilitate aclean, trouble-free KAV-250a and KAV-250aJ3 require at least two inches (5 cm) of clearance each side and at least two inches (5 cm) of clearance above the component to provideadequate amplifier does not require any type of special rack or cabinet for installation. Forthe dimensions of your amplifier see Specifications, on pages 30 and the amplifier as close to the loudspeakers as possible and keep the speakercable length to a minimum. Speaker cable adds impedance to the load the amplifiermust drive, regardless of the cable s gauge. Krell amplifiers drive the lowestimpedances with ease, but long speaker cables reduce the maximum power that isdelivered to the POWER GUIDELINESK rell recommends operating each amplifier from a dedicated 15-amp AC power maximum power output, operate the KAV-250a or KAV-250a/3 amplifier from adedicated 20-amp AC power and KAV-250a/3 Amplifiers3 FIGURE 1 THE KAV-250a FRONT PANEL1 21 Power Button2 Power LEDF ront Panel Description: KAV-250aSee Figure 1 on page 41 Power ButtonUse this button to turn the KAV-250a power on and off and also to switch the 12 VDCoutput (12 V trigger) on and Power LEDThe blue power LED illuminates when the amplifier is and KAV-250a/3 Amplifiers5 FIGURE 2 THE KAV-250a BA(.)

8 K PANEL511 12 1013 Balanced Inputs3 Right Input4 Left Input (Bridged)Single-ended Inputs5 Right Input6 Left Input (Bridged)Amplifier Channel Outputs7 Right Output (Bridged-)8 Left Output (Bridged+)Fuses9 AGC~ Fuses10 Line FuseRemote Controls11 12 VDC Remote Power Out12 12 VDC Remote Power InPower13 IEC Power ConnectorBack Panel Description: KAV-250aSee Figure 2 on page 6 The KAV-250a back panel provides connections for all inputs and outputs, remotecontrol input and output links, and AC power supply. Inputs and outputs labeled left andright are on the left and right side of the amplifier, respectively, when viewing theamplifier from the front Inputs3, 4 InputsThese are the right (3) and the left (4) KAV-250a channel inputs for output devices balanced XLR Inputs5,6 InputsThese are the right (5) and the left (6) KAV-250a channel inputs for output devices single-ended RCA left balanced or single-ended inputs are used for bridged operation.

9 SeeReconfiguring the KA V-250a for Bridged Operation, on page Channel Outputs7 Output Bridged(-)8 Output Bridged(+)These are the right (7) and left (8) KAV-250a amplifier channel outputs with five-wayloudspeaker binding posts. The loudspeaker binding post terminals accept spade lugs,bare wire, banana plugs, or pins. Use the red terminal for the positive connection andthe black terminal for connection. For information on loudspeakerconnections for bridged operation, see Reconfiguring the lEA V-250a for BridgedOperation, on page AGC-12 FusesThe AGC 12 Volt loudspeaker fuses protect the KAV-250a against short circuits inloudspeaker Line FuseThe line fuse protects the KAV-250a against short circuits in internal power must be replaced with the fuse value specified on the KA V-250a back panel. Usea 20 amp slow-blow line fuse for 100/120 V systems or a 12 amp slow-blow line fuse for220/240 V and KAV-250a/3 Amplifiers7 Back Panel Description, continuedRemote Controls11 12 VDC Remote Power Out12 12 VDC Remote Power InThe KAV-250a is equipped with an output that sends 12 VDC power on/off (12 trigger) signals to other Krell components and other devices that incorporate 12 V trigger.

10 This allows you to turn the KAV-250a on and off using a Krell or othercomponent in a custom VDC Out/in (12 V trigger) remote power is limited to 30 the owner s manual of any component used in a custom installation to take fulladvantage of the KA V-250a remote Supply13 IEC ConnectorThe KAV-250a is equipped with a standard female IEC power connector, for use withthe provided AC power cord,8 KAV-250a and KAV-250a/3 AmplifiersFIGURE 3 THE KAV-250a/3 FRONT PANEL14 1514 Power Button15 Power LEDF ront Panel Description: KAV-250a/3 See Figure 3 on page 914 Power ButtonUse this button to turn the KAV-250a/3 power on and off and also to switch the 12 VDCoutput (12 V trigger) on and Power LEDThe blue power LED illuminates when the amplifier is powered and KAV-250a/3 AmplifiersFIGURE 4 THE KAV-250a/3 BACK PANEL1619172o182125 2225 2325 2427 28 2629 Balanced Inputs16 Right Input17 Center Input18 Left InputSingle-ended Inputs19 Right Input20 Center Input21 Left InputAmplifier Channel Outputs22 Right Output23 Center Output24 Left OutputFuses25 AGC e~Euses ~----- ~26 Line FuseRemote Controls27 12 VDC Remote Power Out28 12 VDC Remote Power tnPower29 IEC Power Panel Description: KAV-250a/3 See Figure 4 on page 11 The KAV-250a/3 back panel provides connections for all inputs and outputs, remotecontrol input and output links, and AC power supply.