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Troubleshooting System Noise

Krell Showcase Amplifier

13

When you mix and match high-performance audio components,
each with its own ground potential, a low frequency hum may occur
in one or all loudspeakers. If this happens when you place the
Showcase Amplifier into your system, follow these simple trou-
bleshooting steps:

1. Check that all input and output connections are of sound 

construction. 

2. With the amplifier off, remove all the interconnect cables, then

turn the amplifier on. If the hum disappears, turn the amplifier
off and reinsert one of the interconnect cables. Turn the 
amplifier back on.

3. If the hum reappears with the interconnect cable reinserted, the

cable may need to be replaced. Turn the amplifier off and con-
nect a different interconnect cable to the same location. Turn
the amplifier back on. 

4. If the hum disappears with the interconnect cable reinserted,

that cable most likely is sound.

5. Turn the amplifier off, disconnect the interconnect cable, and re-

connect one of the other interconnect cables.

6. Repeat steps 3 through 5 until you have checked each inter-

connect cable.

7. If all the interconnect cables appear to be sound, and you still

have hum, you may be experiencing a ground loop. Please
contact your authorized Krell dealer, distributor, or Krell for sug-
gestions on how to eliminate the hum.

Summary of Contents for Showcase 5

Page 1: ...Instructions for Use Owner s Reference THE LEADER IN AUDIO ENGINEERING Showcase 7 Showcase 6 Showcase 5 Multichannel Amplifier ...

Page 2: ...and sides of the amplifier must be unob structed at all times during operation Do not place flammable material above or beneath the amplifier Contact your authorized Krell dealer distributor or Krell before using any devices designed to alter or stabilize the AC power for the Showcase Amplifier Before connecting the Showcase Amplifier make sure the amplifier is turned off and any output device suc...

Page 3: ...lines 4 FRONT PANEL DESCRIPTION 6 BACK PANEL DESCRIPTION 8 CONNECTING THE SHOWCASE AMPLIFIER TO YOUR SYSTEM 10 Input and Output Connections 10 AMPLIFIER OPERATION 12 On Off and Operation 12 TROUBLESHOOTING SYSTEM NOISE 13 QUESTIONS AND ANSWERS 14 WARRANTY 15 RETURN AUTHORIZATION PROCEDURE 16 SPECIFICATIONS 17 Page ...

Page 4: ...iv Krell Showcase Amplifier FIGURE 1 The Showcase Amplifier Front Panel 5 FIGURE 2 The Showcase Amplifier Back Panel 7 Illustrations Page ...

Page 5: ...even The Showcase Amplifier has balanced and single ended inputs for compatibility with other components The amplifiers can be operated using the 12 VDC power on off 12 V trigger signals from other components The Showcase Amplifier is versatile fitting a variety of installations including rack mounted and inside cabinetry Please contact your Krell authorized dealer or distributor for infor mation ...

Page 6: ...s are not recommend ed for connections requiring long cable runs Off When the AC power cord is not plugged into the wall the red stand by LED is not illuminated and the component is off Stand by Mode When the AC power cord is plugged into the wall the red stand by LED illuminates indicating that the component is in the stand by mode This low power consumption status keeps the audio and cir cuits a...

Page 7: ...n card Two people are needed to remove the amplifier from the shipping box 2 Grasp the underside of the amplifier and lift it straight out of the shipping box 3 Place the amplifier in a safe location and remove the protective plastic wrapping If any of these items are not included in the shipping box please contact your authorized Krell dealer distributor or Krell for assistance Save all packing m...

Page 8: ...For the dimensions of your amplifier see Specifications on page 17 Place the amplifier as close to the loudspeakers as possible and keep the loudspeaker cable length to a minimum Loudspeaker cable adds impedance to the load the amplifier must drive regard less of the cable s gauge Krell amplifiers drive the lowest imped ances with ease but long loudspeaker cables reduce the maximum power that is d...

Page 9: ...1 Power Button 2 Stand by LED 3 Power LED S H O W C A S E AMPLIFIER 2 1 3 STAND BY POWER Figure 1 The Showcase Amplifier Front Panel ...

Page 10: ...l modes and also to switch the 12 VDC output 12 V trigger on and off 2 Stand by LED The red stand by LED illuminates when the AC power cord is plugged into the wall The stand by LED flashes when the protec tion circuit is activated 3 Power LED The blue power LED illuminates when the amplifier is in the opera tional mode 6 Krell Showcase Amplifier Front Panel Description See Figure 1 on page 5 ...

Page 11: ...RIES INC 45 CONNAIR ROAD ORANGE CT 06477 3650 USA 50 60 Hz MADE IN USA 30mA max OUT IN 12VDC NO USER SERVICEABLE PARTS INSIDE Figure 2 The Showcase Amplifier Back Panel Balanced Inputs 4 Inputs 1 7 Single Ended Inputs 5 Inputs 1 7 Amplifier Channel Outputs 6 Outputs 1 7 Remote Connections 7 12 VDC Remote Power Out 8 12 VDC Remote Power In Power 9 IEC Connector and Fuseholder ...

Page 12: ...tputs 1 7 The Showcase Amplifier has seven amplifier channel outputs The loudspeaker binding post terminals accept spade lugs bare wire or pins Use the red terminal for the positive connection and the black terminal for the negative connection BALANCED INPUTS SINGLE ENDED INPUTS AMPLIFIER CHANNEL OUTPUTS BACK PANEL REMOTE CONNECTIONS Tighten loudspeaker binding posts by hand only 7 12 VDC Remote P...

Page 13: ...n a custom installation Consult the owner s manual of each component used in a custom installa tion to take full advantage of the Showcase Amplifier remote capability 9 IEC Connector and Fuseholder The connector is for use with the provided IEC standard 15 amp power cord The AC mains fuse protects the Showcase Amplifier in the event of an internal fault The AC mains fuse must be replaced with the ...

Page 14: ...The XLR pin configuration is described below Pin 1 Shield ground Pin 2 Non inverting hot 0 Pin 3 Inverting cold 180 Follow these steps to connect the Showcase Amplifier to your sys tem 1 Make sure all power sources and components are off before connecting inputs and outputs 2 Neatly organize the wiring between the amplifier and all system components Separate AC wires from audio cables to prevent h...

Page 15: ...rminals accept spade lugs bare wire or pins Use the red terminal for the positive connection and the black terminal for the negative connection Tighten loudspeaker binding posts by hand only 5 Plug the end of the AC power cord into the AC wall outlet The amplifier is now ready for operation See Amplifier Operation on page 12 The Showcase 5 and Showcase 6 amplifiers may be upgraded with addi tional...

Page 16: ...loudspeakers and loudspeaker cables for poten tial short circuits before plugging the amplifier back into the wall outlet 3 Press the power button 1 on the front panel The blue power LED 3 illuminates and you hear a click The amplifier is in the operational mode Krell recommends leaving the Showcase Amplifier in the stand by mode unless you will not be playing music for a long time Always turn the...

Page 17: ...onnect cables Turn the amplifier back on 3 If the hum reappears with the interconnect cable reinserted the cable may need to be replaced Turn the amplifier off and con nect a different interconnect cable to the same location Turn the amplifier back on 4 If the hum disappears with the interconnect cable reinserted that cable most likely is sound 5 Turn the amplifier off disconnect the interconnect ...

Page 18: ...ed inputs a loud buzz comes from my loudspeakers What is it A Check that the shorting pins for the Showcase Amplifier are inserted into the XLR inputs the unit is shipped with the pins in place When using the single ended inputs shorting pins must be inserted between pins 1 and 3 to keep external noise from corrupting the signal For more information see Connecting the Showcase Amplifier to Your Sy...

Page 19: ...e even if the product is within the warranty period Freight to the factory is your responsibility Return freight within the United States U S A is included in the warranty If you have purchased your Krell product outside the U S A and wish to have it serviced at the factory all freight and associated charges to the factory are your responsibility Krell will pay return freight to the U S A based fr...

Page 20: ...ve been made in advance Proof of purchase will be required for warranty validation at the time of hand delivery Use the original packaging to ensure the safe transit of the product to the factory dealer or distributor Krell may at its discretion return a product in new packaging and bill the owner for such packaging if the product received by Krell was boxed in nonstandard packaging or if the orig...

Page 21: ...POWER CONSUMPTION Stand by 90 W Stand by 80 W Stand by 70 W Idle 150 W Idle 130 W Idle 110 W Max 1600 W Max 1400 W Max 1200 W INPUTS 7 single ended 6 single ended 5 single ended via RCA connectors via RCA connectors via RCA connectors 7 balanced 6 balanced 5 balanced via XLR connectors via XLR connectors via XLR connectors OUTPUTS 7 channels via 5 way 6 channels via 5 way 5 channels via 5 way bind...

Page 22: ...ustries Inc 45 Connair Road Orange CT 06477 3650 USA TEL 203 799 9954 FAX 203 891 2028 E MAIL krell krellonline com WEBSITE http www krellonline com Showcase 7 Showcase 6 Showcase 5 Multichannel Amplifier v 02 1 ...

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