Home

Krell Industries 350Mcx Stereo Amplifier User Manual

image

Contents

1. Note Krell Link uses standard five pin MIDI commu nication cables sometimes referred to as MIDI Plus cables MIDI cables can be purchased from your authorized distributor or dealer or from an audio supply store How to Connect Components through Krell Link 1 Turn all components off using the back panel power breaker switch This ensures that the components are synchronized when the MIDI cable is connected 2 Select the component to be the control com ponent The control component must be in plain view for proper remote control opera tion 3 Connect one end of the MIDI cable to the Krell Link out connector on the back panel of the component Connecting continued 4 Connect the other end of the MIDI cable to the Krell Link in connector on the next com ponent To link another component connect a sec ond MIDI cable to the Krell Link out con nector on the back panel of the second component Connect the remaining end of the MIDI cable to the Krell Link in connec tor on the back panel of a third component 5 Link additional components if desired as described in Steps 3 and 4 The components are now ready for operation with Krell Link DC PROTECTION CIRCUITRY Full Power Balanced amplifiers use unobtrusive direct current DC protection circuitry that strips DC from the signal without corrupting sound reproduction Full Power Balanced amplifiers feature direct coupled circuitry from input to output
2. 20 kHz lt 0 16 100 kOhms 2 87 Vrms 8Ohms 450 W 4Ohms 900 W 2 Ohms 1 800 W Peak to Peak 170 V RMS 60 V Stand by 37 5 W Idle 175 W Max 3 000 W 1 balanced via XLR connectors 1 Krell CAST via 4 pin bayonet connectors 2 pair one upper one lower Optional 12 5w x 10 5h x 19 0d 31 8w x 26 7h x 48 3d 110 0 Ib 50 0 kg 98 0 Ib 44 5 kg FPB 750Mc 20 Hz to 20 kHz 0 dB 0 05 dB 0 1 Hz to 240 kHz 0 dB 3 dB 121 dB 26 4 dB 1 kHz lt 0 03 20 kHz lt 0 16 100 kOhms 3 71 Vrms 8Ohms 750 W 4 Ohms 1 500 W 2 Ohms 3 000 W Peak to Peak 240 V RMS 84 V Stand by 42 5 W Idle 220 W Max 6 000 W 1 balanced via XLR connectors 1 Krell CAST via 4 pin bayonet connectors 2 pair one upper one lower Optional 12 5w x 10 5h x 25 0d 31 8w x 26 7h x 67 3d 155 0 Ib 70 5 kg 140 0 Ib 63 6 kg 23 Krell Industries Inc 45 Connair Road Orange CT 06477 3650 USA TEL 203 799 9954 FAX 203 891 2028 E MAIL krell krellonline com WEB SITE hittp www krellonline com Full Power Balanced X Series Power Amplifiers 700cx 400cx 300cx Stereo 750Mcx 450Mcx 350Mcx Monaural with Krell CAST Il Technology v 02 0
3. OUTPUTS SPEAKER BINDING POSTS REMOTE CONTROL DIMENSIONS INCHES CENTIMETERS WEIGHT SHIPPING UNIT ONLY FPB 300cx 20 Hz to 20 kHz 0 dB 0 05 dB 0 1 Hz to 240 kHz 0 dB 3 dB 113 dB 26 4 dB 1 kHz lt 0 03 20 kHz lt 0 16 100 kOhms 2 34 Vrms 8 Ohms 300 W 4 Ohms 600 W 2 Ohms 1200 W Peak to Peak 138 V RMS 49 V Stand by 60 W Idle 175 W Max 1 700 W 1 pair balanced via XLR connectors 1 pair CAST via 4 pin bayonet connectors 4 pair upper left lower left upper right lower right Optional 19 0w x 10 3h x 17 0d 48 3w x 26 2h x 43 2d 107 0 Ib 48 6 kg 90 0 Ib 40 9 kg FPB 400cx 20 Hz to 20 kHz 0 dB 0 05 dB 0 1 Hz to 240 kHz 0 dB 3 dB 117 dB 26 4 dB 1 kHz lt 0 03 20 kHz lt 0 16 100 kOhms 2 71 Vrms 8Ohms 400 W 40Ohms 800 W 2 Ohms 1 600 W Peak to Peak 170 V RMS 60 V Stand by 75 W Idle 350 W Max 3 000 W 1 pair balanced via XLR connectors 1 pair CAST via 4 pin bayonet connectors 4 pair upper left lower left upper right lower right Optional 19 0w x 10 3h x 19 7d 48 3w x 26 2h x 50 0d 127 0 Ib 57 7 kg 110 0 Ib 50 0 kg FPB 700cx 20 Hz to 20 kHz 0 dB 0 05 dB 0 1 Hz to 240 kHz 0 dB 3 dB 120 dB 26 4 dB 1 kHz lt 0 03 20 kHz lt 0 16 100 kOhms 3 58 Vrms 8Ohms 700 W 4 Ohms 1 400 W 2 Ohms 2 800 W Peak to Peak 240 V RMS 84 V Stand by 85 W Idle 430 W Max 6 000 W 1 pair balanced via XLR connectors 1 pair
4. The industry standard for professional and sound recording installations balanced connections have 6 dB more gain than single ended connections and allow the use of long interconnect cables Bal anced connections are completely immune to induced noise from the system or the environ ment Krell Current Audio Signal Transmission CAST A proprietary Krell circuit technology for connect ing analog components in which the audio waveform is transmitted between components in the current rather than voltage domain The speed and bandwidth provided by Krell CAST and the CAST circuitry update Krell CAST Il yield accurate realistic music reproduction Krell components connected via CAST and CAST Il perform as if they are all part of a single circuit Definition of Terms continued Single ended A two wire input or output circuit Use care when using single ended connections as the ground connection is made last and broken first Turn the system off prior to making or breaking single ended connections Single ended connections are not recommended for connections requiring long cable runs OPERATION Off When the power switch on the back panel is placed in the down position and the blue power LEDs turn off the component is off Operational Mode When the power button on the front panel is pressed and the three blue power LEDs illumi nate the component is in the operational mode and ready to play music Stand by Mode
5. however a pair of Full Power Balanced Monau ral amplifiers are required for stereo operation Full Power Balanced amplifiers can be config ured to accommodate any sophisticated music or home theater system and can be operated by an optional remote control or through the remote control of other Krell components This owner s reference manual contains impor tant information on placement installation and operation of the Full Power Balanced ampli fiers Please read this information carefully A thorough understanding of these details will help ensure satisfactory operation and long life for your Full Power Balanced amplifier and related system components Krell Full Power Balanced X Series Power Amplifiers Definition of Terms Following are the definitions of key terms used in your owner s reference manual CONFIGURATIONS Krell Link A method of synchronizing remote control oper ation for Krell systems that include multiple pre amplifiers amplifiers and associated compo nents When Krell Link in out connections are used the remote capabilities of the linked com ponents are controlled from one component called the control component The linked com ponents respond to stand by and operational mode commands from the control component via MIDI cables INPUT AND OUTPUT CONNECTIONS Balanced A symmetrical input or output circuit that has equal impedance from both input terminals to a common ground reference point
6. CAST via 4 pin bayonet connectors 4 pair upper left lower left upper right lower right Optional 19 0w x 10 3hx 25 5d 48 3wx 26 2hx 64 8d 200 0 Ib 90 9 kg 180 0 Ib 81 8 kg All operational features functions specifications and policies are subject to change without notification 22 Krell Full Power Balanced X Series Power Amplifiers Specifications Full Power Balanced 350Mcx 450Mcx 750Mcx Monaural Amplifiers FREQUENCY RESPONSE SIGNAL TO NOISE RATIO A WEIGHTED GAIN TOTAL HARMONIC DISTORTION THD ALL BALANCED UNWEIGHTED INPUT IMPEDANCE INPUT SENSITIVITY OUTPUT POWER EACH CHANNEL DRIVEN OUTPUT VOLTAGE POWER CONSUMPTION INPUTS OUTPUTS SPEAKER BINDING POSTS REMOTE CONTROL DIMENSIONS INCHES CENTIMETERS WEIGHT SHIPPING UNIT ONLY FPB 350Mc 20 Hz to 20 kHz 0 dB 0 05 dB 0 1 Hz to 240 kHz 0 dB 3 dB 114 dB 26 4 dB 1 kHz lt 0 03 20 kHz lt 0 16 100 kOhms 2 53 Vrms 8Ohms 350W 40Ohms 700 W 2 Ohms 1 400 W Peak to Peak 138 V RMS 49 V Stand by 30 W Idle 150 W Max 1 700 W 1 balanced via XLR connectors 1 Krell CAST via 4 pin bayonet connectors 2 pair one upper one lower Optional 12 5w x 10 5h x 16 0d 31 8w x 26 7h x 40 6d 79 0 Ib 35 9 kg 68 0 Ib 31 0 kg Krell Full Power Balanced X Series Power Amplifiers FPB 450Mc 20 Hz to 20 kHz 0 dB 0 05 dB 0 1 Hz to 240 kHz 0 dB 3 dB 118 dB 26 4 dB 1 kHz lt 0 03
7. This topology eliminates all cou pling capacitors from the audio signal path Coupling capacitors block damaging DC but have sonic characteristics that corrupt sound reproduction Note For more information about DC protection cir cuitry features see Amplifier Troubleshooting on page 17 USING A TUBE PREAMPLIFIER The high DC output of tube preamplifiers may exceed the DC protection circuitry of Full Power Balanced amplifiers Excessive DC level in a signal can damage amplifiers speak ers or both The coupling capacitors in Full Power Balanced amplifiers must be engaged when using a tube preamplifier An authorized Krell dealer distributor or Krell must activate these capacitors Coupling capacitors must be inserted into the signal path by your authorized Krell dealer dis tributor or Krell before you can use your Full Power Balanced amplifier with a tube preampli fier IMPORTANT Please read the Warranty on page 20 to understand the warranty limitations of Full Power Balanced amplifiers when used with tube preamplifiers Krell Full Power Balanced X Series Power Amplifiers Amplifier Operation Full Power Balanced amplifiers are easy to install and operate However it is important to exercise care during operation due to the amplifiers enormous power output Switching between active sources such as a CD player tape monitor or VCR without muting the pre amplifier output or bumping or miscuing a sou
8. angle illuminates when the back panel power breaker switch has been moved to on engag ing the input circuitry and placing the amplifier in stand by mode 2 Bias LED The blue bias LED lower left of triangle illumi nates after the front panel power button is pressed indicating that the Sustained Plateau Bias Ill is engaged 3 Power Button Use the silver power button to power on the amplifier from stand by mode 4 Infrared Sensor The infrared sensor receives the signal from a remote control 5 Krell CAST LED The red Krell CAST LED center of triangle illu minates when a Krell CAST input on the back panel is connected to another Krell product with a Krell CAST output 6 Regulator LED The blue regulator LED lower right of triangle illuminates after the front panel power button is used to power on from stand by mode indicat ing that the regulator is providing power to the output stage 8 Note An optional remote control is available for Full Power Balanced amplifiers FULL POWER BALANCED 750Mcx 450Mcx AND 350Mcx MONAURAL POWER AMPLIFIERS See Figure 2 on page 7 7 Power Stand by LED The blue power stand by LED top of LED tri angle illuminates when the back panel power breaker switch has been moved to on engag ing the input circuitry and placing the amplifier in stand by mode 8 Bias LED The blue bias LED lower left of triangle illumi nates after the front panel power button is pressed indicat
9. facilitate a clean trouble free installation The Full Power Balanced amplifier requires at least two inches 5 cm of clearance on each side and at least eight inches 20 cm of clear ance above the component to provide ade quate ventilation Although Sustained Plateau Bias III circuitry reduces the high heat dissipation and heat out put of traditional Class A circuitry Full Power Balanced amplifiers still can become hot under normal operation When the front and rear of a cabinet are open the air space between the chassis and shelf must be unobstructed If you place the amplifi er in a closed cabinet you may need to modify shelf spacing or use small fans to increase ven tilation For the dimensions of your Full Power Balanced amplifier see Specifications on pages 22 23 Place the amplifier as close to the speakers as possible Krell CAST technology permits you to use interconnect cables of any length see Rev olutionary Krell CAST and CAST II Technol ogy on page 3 however try to keep the cable length to a minimum All Full Power Balanced amplifiers drive the lowest impedances with ease When imped ance is added due to long speaker cable lengths amplifier power is wasted in the cable Long speaker cables reduce the maximum power that is delivered in the speakers Krell Full Power Balanced X Series Power Amplifiers Placement continued AC POWER GUIDELINES The Full Power Balanced 300cx and 350Mcx amplifi
10. 23 Balanced Input Breaker Switch 10 Krell Full Powered Balanced X Series Power Amplifiers Back Panel Description The back panel provides connections for all inputs and outputs power on off and remote control links The back panel also has handles that allow you to safely and easily move the amplifier FULL POWER BALANCED 700cx 400cx AND 300cx STEREO POWER AMPLIFIERS See Figure 1 on page 6 13 Left and Right Speaker Binding Posts Full Power Balanced 700cx 400cx and 300cx stereo amplifiers are equipped with four pairs of speaker binding posts upper left lower left upper right and lower right Notes Two pairs of speaker binding posts are used for each channel of amplification On the stereo or monaural Full Power Balanced amplifiers either the upper or the lower pair can be used with speakers having two pairs of binding posts For biwiring applications with speakers having more than one pair of binding posts use both upper and lower pairs of speaker binding posts See the speaker s instruction manual for biwiring connections Speaker binding posts for stereo and monaural amplifiers accept spade lugs only Bare wire banana lugs or pins will not work Use the red terminal for the positive connection and the blue terminal for the negative connection 14 Krell CAST Inputs Full Power Balanced 700cx 400cx and 300cx stereo amplifiers are equipped with one left Krell CAST input and one right Krell CAST input v
11. A low power consumption status that keeps the audio and regulator circuits at idle Krell recom mends leaving the component in the stand by mode when it is not playing music TECHNOLOGY Krell Current Mode A proprietary Krell circuit topology in which the audio gain stages of a component operate in the current rather than voltage domain This unique technology provides the component with exceptional speed and a wide bandwidth Krell Sustained Plateau Bias Ill A patented microprocessor control system that maintains Class A bias operation regardless of musical demand Class A bias is the most accu rate method used to amplify musical signals The new Sustained Plateau Bias III software is featured in the Full Power Balanced X Series amplifiers and was developed from the algo rithm utilized in the Master Reference Amplifier Sustained Plateau Bias III maximizes an ampli fier s efficiency both in power consumption and heat generation Krell Full Powered Balanced X Series Power Amplifiers Revolutionary Krell CAST and CAST Il Technology Current Audio Signal Transmission termed CAST is a revolutionary method of connecting analog audio components for unparalleled sonic performance CAST circuitry and the CAST circuitry update Krell CAST II combine innovative engineering with existing Krell Cur rent Mode technology to create entire CAST systems that reproduce music with incredible range tonality and precision Voltage S
12. SS i Full Power Balanced X Series Power Amplifiers 700cx 400cx 300cx Stereo 750Mcx 450Mcx 350Mcx Monaural with Krell CAST Il Technology THE LEADER IN AUDIO ENGINEERING Instructions for Use Owner s Reference Full Power Balanced Krell Industries Inc X Series Power Amplifiers 45 Connair Road Orange CT 06477 3650 USA 700cx 400cx 300cx Stereo 9 TEL 203 799 9954 750Mex 450Mex FAX 203 891 2028 350Mcx Monaural E MAIL krell krellonline com with Krell CAST II Technology WEBSITE http www krellonline com v 02 0 cE This product complies with the EMC directive 89 336 EEC and the low voltage directive 73 23 EEC WARNINGS The Full Power Balanced amplifier must be placed on a firm level surface where it is not exposed to drip ping or splashing The ventilation grids on the top of the Full Power Balanced amplifier must be unobstructed at all times during operation Do not place flammable material on top of or beneath the component Before making connections to the Full Power Balanced amplifier ensure that it is off and the preamplifier is in mute or stand by mode Make sure all cable terminations are of the highest quality and free from frayed ends short circuits or cold solder joints The differential circuitry employed with Full Power Balanced amplifiers requires special attention when connect ing speakers Do not connect the negative speaker terminals together Do not connect the negative speaker ter minal
13. The prod uct will be returned to original factory layout specifications at the owner s expense before it is repaired All repairs required after the product has been returned to original fac tory specifications will be charged to the customer at cur rent parts and labor rates All operational features functions and specifications and policies are subject to change without notification To register your product for warranty benefits please complete and return the Warranty Reg istration Card enclosed in the shipping box within 15 days of purchase Thank you Krell Full Power Balanced X Series Power Amplifiers Return Authorization Procedure If you believe there is a problem with your com ponent please contact your dealer distributor or the Krell factory to discuss the problem before you return the component for repair To expedite service you may wish to complete and e mail the Service Request Form in the Service Section of our website at www krellonline com To contact the Krell Service Department TEL 203 799 9954 Monday Friday 9 00 AM to 5 00 PM EST FAX 203 799 9796 E MAIL service krellonline com WEBSITE www krellonline com Full Power Balanced X Series Amplifier PRODUCT NAME MODEL NUMBER SERIAL NUMBER Krell Full Power Balanced X Series Power Amplifiers To return this product to Krell please follow this procedure so that we may serve you better 1 Obtain a Return Authorization Numbe
14. al anced amplifiers through a speaker selector box A No Most speaker selector boxes use a com mon ground scheme The differential circuitry in Full Power Balanced amplifiers prohibits the use of these devices Do not connect a Full Power Balanced amplifier to a speaker selector Krell Full Power Balanced X Series Power Amplifiers device that employs a common ground scheme as it may short circuit the amplifier output Q My speakers have only one pair of binding posts but my Full Power Balanced stereo amplifier has two pairs Which pair of speaker binding posts should use the upper or the lower A The upper and lower pair of speaker bind ing posts on Full Power Balanced stereo ampli fiers are identical You can use either the upper or lower pair they work and sound the same See Connecting the Full Power Balanced Amplifier to Your System on page 13 Q My speakers are rated for 150 Watts Are the Full Power Balanced 400cx or 700cx mod els too powerful for them A No A speaker seldom is damaged from overdriving More often damage occurs when an amplifier that lacks sufficient power is asked to handle heavy demand situations such as high playback levels These amplifiers may have very high 8 Ohm power ratings but in heavy demand situations they can be driven into clipping in which DC current goes to speakers due to loss of amplifier power Clip ping can damage speakers Avoid damage to your speakers by revie
15. ates and remains illuminated at all times during the stand by or power on modes 3 With the preamplifier muted or volume con trol completely lowered select a source Increase the volume control to the desired listening level 4 When turning off the system mute or com pletely lower the preamplifier volume or place the Full Power Balanced amplifier in the stand by power mode by pressing the power button on the front panel It is now safe to turn off the rest of the system Note For best performance of Full Power Balanced amplifiers leave the back panel power breaker switch on at all times KRELL LINK OPERATION 1 When all components are linked place each component in the stand by mode by moving the back panel power breaker switch to the up position This ensures that all components will be synchronized when signals from the control component are sent to the linked components in the system 2 When the components are in stand by switch the control component to the opera tional mode from the control component s front panel or by using the component s remote control The linked components switch to the oper ational mode simultaneously A linked component can be switched between the operational mode and stand by individual ly from its front panel Switching a linked com ponent temporarily breaks the chain of linked components To re establish linked operation return all components to stand by 15 Remote Con
16. based freight for warder of your choice Freight and other charges to ship the unit from the freight forwarder to you are also your respon sibility Krell is not responsible for any damage incurred in transit Krell will file claims for damages as necessary for units dam aged in transit to the factory You are responsible for filing claims for shipping damages during the return shipment Krell does not supply replacement parts and or products to the owner of the unit Replacement parts and or products will be furnished only to the distributor performing service on this unit on an exchange basis only any parts and or prod ucts returned to Krell for exchange become the property of Krell No expressed or implied warranty is made for any Krell product damaged by accident abuse misuse natural or personal disaster or unauthorized modification Any unauthorized voltage conversion disassembly component replacement perforation of chassis updates or modifications performed to the unit will void the warranty The operating voltage of this unit is determined by the fac tory and can only be changed by an authorized Krell distrib utor or at the factory The voltage for this product in the U S A cannot be changed until six months from the original purchase date In the event that Krell receives a product for warranty ser vice that has been modified in any way without Krell autho rization all warranties on that product will be void
17. d signal are non existent How CAST and Krell Current Mode Interact While CAST is a new method of transferring the musical signal between components its origin stems from Krell Current Mode the technology developed to transfer the musical signal within a component CAST combined with Krell Cur rent Mode takes circuitry signal transmission to the next evolutionary level In essence Krell Current Mode maintains the integrity of the sig nal within the component and CAST preserves the transmitted signal between components Together CAST and Krell Current Mode tech nologies unify separate Krell components into a single global circuit CAST Cable Construction A CAST system uses cables manufactured by Krell and other manufacturers specially licensed by Krell Thin and flexible CAST cables are constructed with the same build quality as other Krell products and are aesthet ically matched to the components that Krell manufactures An all metal body and locking connectors with gold contacts are part of the standard no compromise specification devel oped for every CAST cable made The Best Musical Performance When you operate a CAST system you will hear significant improvements in every perfor mance area speed precision dynamic range depth and width of the sound stage transient impact tonal balance harmonic distortion and more The goal for CAST is the same company goal used for all Krell products Krell strives for the delive
18. de the speaker binding posts to help you easily and safely move the amplifier 11 Back Panel Description continued FULL POWER BALANCED 750Mcx 450Mcx AND 350Mcx MONAURAL POWER AMPLIFIERS See Figure 4 on page 10 20 Handle All Full Power Balanced monaural amplifiers are equipped with a handle located beside the speaker binding posts to help you easily and safely move the amplifier 21 Speaker Binding Posts Full Power Balanced 750Mcx 450Mcx and 350Mcx monaural amplifiers are equipped with two pairs of speaker binding posts one upper pair and one lower pair For stereo operation two monaural amplifiers are required 22 Krell CAST Input Full Power Balanced 750Mcx 450Mcx and 350Mcx monaural amplifiers are equipped with one Krell CAST input via a 4 pin bayonet con nector The Krell CAST input allows the Full Power Balanced amplifier to be connected to the KPS 25sc Krell Playback System and other CAST equipped components 23 Balanced Input Full Power Balanced 750Mcx 450Mcx and 350Mcx monaural amplifiers are equipped with one balanced input via an XLR connector 24 AC Mains Power Cord All Full Power Balanced amplifiers are equipped with a permanently attached AC power cord 25 Krell Link Out In Full Power Balanced amplifiers are equipped with Krell Link Remote out in connectors that allow the remote control to operate a linked amplifier configuration See Krell Link Connec tions on page 13 for more in
19. ers need to be operated from a dedicat ed AC power line rated at a minimum of 15 amps The Full Power Balanced 700cx 750Mcx 400cx and 450Mcx amplifiers need to Krell Full Power Balanced X Series Power Amplifiers be operated from a dedicated AC power line rated at a minimum of 20 amps Please contact your authorized Krell dealer dis tributor or Krell before using any devices designed to alter or stabilize the AC power for Full Power Balanced amplifiers FIGURE 1 FULL POWER BALANCED STEREO AMPLIFIER FRONT PANEL Full Power Balanced 700cx lt i 1 Power Stand by LED 4 Infrared Sensor 2 Bias LED 5 Krell CAST LED 3 Power Button 6 Regulator LED 6 Krell Full Powered Balanced X Series Power Amplifiers FIGURE 2 FULL POWER BALANCED MONAURAL AMPLIFIER FRONT PANEL Full Power Balanced 750Mcx lt i 7 8 9 10 11 12 7 Power Stand by LED 10 Infrared Sensor 8 Bias LED 11 Krell CAST LED 9 Power Button 12 Regulator LED Krell Full Powered Balanced X Series Power Amplifiers 7 Front Panel Description The front panel accesses power on stand by and infrared sensor remote control functions The power stand by bias regulator and Krell CAST LEDs arranged in a triangle on the front panel above the power button illuminate to indi cate amplifier status FULL POWER BALANCED 700cx 400cx AND 300cx STEREO POWER AMPLIFIERS See Figure 1 on page 6 1 Power Stand by LED The blue power stand by LED top of LED tri
20. formation Note An optional remote control is available for Full Power Balanced amplifiers 26 Back Panel Power Breaker Switch Full Power Balanced amplifiers are equipped with a back panel power breaker switch for powering on the amplifier Powering on using the back panel power breaker switch places the amplifier in stand by mode where it remains until the front panel power button is pressed Note Krell recommends that once the amplifier is powered on from the back panel power breaker switch it remains on in stand by mode even when not in use Krell Full Power Balanced X Series Power Amplifiers Connecting the Full Power Balanced Amplifier to Your System INPUT AND OUTPUT CONNECTIONS Krell recommends using its proprietary Krell CAST system for unparalleled sonic perfor mance between the Full Power Balanced amplifiers and other CAST equipped compo nents and the KPS 25sc Krell Playback Sys tem Full Power Balanced amplifiers also offer bal anced operation The circuitry and connections associated with balanced operation not only can minimize sonic loss but also are immune to induced noise especially for installations using long cables A one piece RCA to XLR adapter is available from Krell Industries to allow single ended oper ation using the balanced XLR inputs The following steps describe how to connect cables to the Full Power Balanced Amplifiers 1 Neatly arrange and organize wiring to and fro
21. hey are of sound construction With the amplifier in stand by mode remove the interconnect cables then press the front panel power button If the hum disappears press the power button to return to stand by mode and reinsert one of the interconnect cables Press the power button again If the hum reappears with one or both intercon nects inserted there may be a defective cable Have the interconnect cables checked before proceeding 2 If the interconnect cables are sound you may be experiencing a ground loop This can often be easily eliminated Please con tact your authorized Krell dealer distributor or Krell for suggestions on how to solve this problem Krell Full Power Balanced X Series Power Amplifiers HOW TO EVALUATE AMPLIFIER OPERATION The amplifiers are protected by a series of non intrusive circuits that constantly evaluate the amplifiers operation This circuitry protects against damaging DC input or output and short circuits see also DC Protection Circuitry on page 14 and monitors regulator operation ensuring constant voltage to the output stage The protection circuitry in a Full Power Bal anced amplifier is designed to prevent damage to the amplifiers or speakers caused by other defective components faulty wiring system mishandling or amplifier failure In addition when a Full Power Balanced ampli fiers DC protection circuitry senses a problem within the system it identifies then indicates the prob
22. ia 4 pin bayonet connectors The Krell CAST inputs allow the Full Power Balanced amplifier to be connected to the KPS 25sc Krell Playback Sys tem and other CAST equipped components Krell Full Power Balanced X Series Power Amplifiers 15 Back Panel Power Breaker Switch Full Power Balanced amplifiers are equipped with a back panel power breaker switch for powering on the amplifier Placing the back panel power breaker switch in the up position places the amplifier in stand by mode where it remains until the front panel power button 3 is pressed Note Krell recommends that the amplifier remain on in stand by mode even when not in use once it is powered on from the back panel power breaker switch 15 16 Left and Right Balanced Inputs Full Power Balanced 700cx 400cx and 300cx stereo amplifiers are equipped with one left bal anced input and one right balanced input via XLR connectors 17 Krell Link Out In Full Power Balanced amplifiers are equipped with Krell Link Remote out in connectors that allow the remote control to operate a linked amplifier configuration See Krell Link Connec tions on page 13 for more information Note An optional remote control is available for Full Power Balanced amplifiers 18 AC Mains Power Cord All Full Power Balanced amplifiers are equipped with a permanently attached AC power cord 19 Handles All Full Power Balanced stereo amplifiers are equipped with two handles located besi
23. ignal Transmission and the Traditional Audio System Traditionally signal is transmitted in the voltage domain between two components In an audio system each component is a discrete entity with unique characteristics that act upon the musical signal independently Each component is unaware of the other components in the system The cables that connect the components each have their own electrical characteristics which affect the sonic presentation of the entire sys tem CAST A New Approach CAST circuitry recognizes signal transmitted in the current domain instead of the voltage domain between each component CAST transmission unifies the individual components and their interconnects into an electrically linked whole The sonic presentation of the entire system remains intact CAST Basics Here s how a CAST audio system works Inter nally each CAST source transfers or amplifies current using Krell Current Mode circuitry This current signal is then output using CAST cir cuitry When the signal is received by a CAST input Krell Current Mode circuitry again takes over until the signal reaches the loudspeaker By maintaining the musical signal in the current domain from beginning to end an entire CAST system behaves as if it is one component With Krell Full Power Balanced X Series Power Amplifiers CAST anomalies of signal transmission between components are eliminated Cable impedances and their effects on the transmitte
24. ing that the Sustained Plateau Bias Ill is engaged 9 Power Button Use the silver power button to power on the amplifier from stand by mode 10 Infrared Sensor The infrared sensor receives the signal from a remote control 11 Krell CAST LED The red Krell CAST LED center of triangle illu minates when a Krell CAST input on the back panel is connected to another Krell product with a Krell CAST output 12 Regulator LED The blue regulator LED lower right of triangle illuminates after the front panel power button is used to power on from stand by mode indicat ing that the regulator is providing power to the output stage Krell Full Power Balanced X Series Power Amplifiers FIGURE 3 FULL POWER BALANCED STEREO AMPLIFIER BACK PANEL gal my nMi ell 00 Me ack NO USER SERVICEAIILE PARTS ISIDE 19 13 14 1516 17 18 16 14 13 19 13 Left and Right Speaker Binding Posts 16 Left and Right Balanced Inputs 14 Krell CAST Inputs 17 Krell Link Out In 15 Back Panel Power Breaker Switch 18 AC Mains Power Cord 19 Handles Krell Full Powered Balanced X Series Power Amplifiers 9 FIGURE 4 FULL POWER BALANCED MONAURAL AMPLIFIER BACK PANEL OUTPUT KRELL KRELL INDUSTRES INC 45 CONNAIR ROAD ORANGE CT 06477 3650 USA FULL POWER BALANCED 750Mcx PATENT Ni 5331291 20 21 22 23 24 2 26 20 Handle 24 AC Mains Power Cord 21 Speaker Binding Posts 25 Krell Link Out In 22 Krell CAST Input 26 Back Panel Power
25. lem by illuminating the front panel blue LEDs as described in the following table Notes The Krell CAST LED illuminates only if a Krell CAST input is being used There are no output fuses in Full Power Bal anced amplifiers If the course of action listed in the table below does not correct the situation please con tact your authorized Krell dealer distributor or Krell AMPLIFIER CONDITION POSSIBLE CAUSES COURSE OF ACTION The output mutes during playback and the following LEDs illuminate Power Stand by and Regulator Bias Excessive DC at the amplifier input Have source unit and preamplifier checked for high DC output If preamplifier is a tube model see Using a Tube Preamplifier on page 14 The amplifier switches to stand by mode and the Power Stand by LED illuminates Electrical short in speaker cables or inside speaker Check all speaker cables for any cuts or frayed edges that might form a connection between the positive and neg ative speaker binding post ter minals The amplifier switches to stand by at high volumes and the Power Stand by LED illuminates Insufficient AC current from the wall outlet Excessive heat Make sure the AC line is at least 15 amps for 300cx and 350Mc amplifiers 400cx 450Mcx 700cx and 750Mcx amplifiers should be operated from a dedicated 20 amp line Allow amplifier to cool before resuming operation See Placement on page 4 for ven tila
26. m the amplifier and all components Sep arate AC wires from audio cables to prevent hum or other unwanted noise from being introduced into the system 2 Connect the Krell CAST cables from your CAST enabled preamplifier source compo nent to the left and right Krell CAST 4 pin bayonet inputs on the amplifier back panel For balanced operation connect the inter connect cable from your preamplifier to the left and right balanced XLR input on the amplifier back panel 3 Connect the speaker cables to the Full Power Balanced amplifier s speaker binding posts located on the amplifier back panel Speaker binding posts for both stereo and monaural amplifiers accept spade lugs only Krell Full Power Balanced X Series Power Amplifiers 4 Insert the end of the AC mains power cord into the AC wall receptacle 5 Proceed with Krell Link Connections if desired or turn to Amplifier Operation on page 15 KRELL LINK CONNECTIONS Krell Link Remote out in connectors on the back panel of the Full Power Balanced amplifi er allow you to synchronize remote control operation for systems that include multiple amplifiers and associated components When the Krell Link Remote out in connectors are used the remote capabilities of the linked com ponents are controlled from one amplifier or preamplifier called the control component The linked components respond to stand by and operational mode commands from the control component via MIDI cables
27. plifiers CONNECTING THE FULL POWER BALANCED AMPLIFIER TO YOUR SYSTEM Input and Output Connections Krell Link Connections DC Protection Circuitry Using a Tube Preamplifier AMPLIFIER OPERATION On Off and Stand by Operation Krell Link Operation REMOTE CONTROL OPERATION How to Turn Off the Amplifier LEDs How to Turn On the Amplifier LEDs How to Switch between Krell CAST and XLR Inputs Using a Dedicated Wall Outlet and Switch AMPLIFIER TROUBLESHOOTING How to Troubleshoot System Noise How to Evaluate Amplifier Operation QUESTIONS AND ANSWERS WARRANTY RETURN AUTHORIZATION PROCEDURE SPECIFICATIONS Krell Full Power Balanced X Series Power Amplifiers 13 13 13 14 14 15 15 15 16 16 16 16 16 17 17 17 19 20 21 22 Illustrations Page FIGURE 1 Full Power Balanced Stereo Amplifier Front Panel 6 FIGURE 2 Full Power Balanced Monaural Amplifier Front Panel 7 FIGURE 3 Full Power Balanced Stereo Amplifier Back Panel 9 FIGURE 4 Full Power Balanced Monaural Amplifier Back Panel 10 iv Krell Full Power Balanced X Series Power Amplifiers Introduction The Full Power Balanced X Series consists of three stereo amplifiers the Full Power Bal anced 700cx 400cx and 300cx Stereo Power Amplifiers and three monaural amplifiers the Full Power Balanced 750Mcx 450Mcx and 350Mcx Monaural Power Amplifiers Installa tion connection and operation of all amplifiers in the Full Power Balanced series are identical
28. r R A number and shipping address from the Krell Service Department 2 Insure and accept all liability for loss of or damage to this product during shipment to the Krell factory and prepay all shipping charges Please see the Warranty page in this manual concerning liability for shipping damage and shipping charges This product may also be hand delivered if arrangements with the Service Department have been made in advance Proof of purchase may be required for warranty validation at the time of hand delivery IMPORTANT Use the original packaging to ensure safe tran sit of this product to the dealer distributor or factory Krell may at its discretion return this product in new packaging and bill the owner for such packaging if the product received by Krell was boxed in non standard packaging or if the original packaging was so damaged that it was unusable If Krell determines that new packag ing is required the owner will be notified before this product is returned To purchase additional packaging please con tact your authorized Krell dealer distributor or the Krell Service Department 21 Specifications Full Power Balanced 300cx 400cx 700cx Stereo Amplifiers FREQUENCY RESPONSE SIGNAL TO NOISE RATIO A WEIGHTED GAIN TOTAL HARMONIC DISTORTION THD ALL BALANCED UNWEIGHTED INPUT IMPEDANCE INPUT SENSITIVITY OUTPUT POWER EACH CHANNEL DRIVEN OUTPUT VOLTAGE POWER CONSUMPTION INPUTS
29. rce can generate large transients at low fre quencies Full Power Balanced amplifiers may generate enough power with these transients to damage loudspeakers IMPORTANT Always mute or fully attenuate the preamplifier level when switching sources Do not change input connections to the amplifi er when the amplifier is on Use care when setting high playback levels Because of their tremendous reserves of clean power Full Power Balanced amplifiers can safe ly drive speakers to higher sound pressure lev els than other amplifiers Always lower the vol ume level at the first sign of speaker distress ON OFF AND STAND BY OPERATION When powering on any system turn on ampli fiers last Turn off amplifiers first 1 Move the back panel power breaker switch to the up position to engage the input cir cuitry and place the amplifier into the stand by mode The front panel blue power stand by LED illuminates 2 Press the silver power button on the amplifi er front panel The blue regulator LED illumi nates Once the regulator provides power to the output stage the blue bias LED illumi nates The Sustained Plateau Bias II system is now engaged After the protection circuitry has confirmed that safe operating conditions exist the input relays engage You hear a click The amplifier is ready for operation Krell Full Power Balanced X Series Power Amplifiers If the Krell CAST input is being used the Krell CAST red LED illumin
30. ry of the best performance of a musi cal event for you using the full expression of technology to date Unpacking Two people are needed to remove the Full Power Balanced amplifier from its shipping box safely and easily 1 Open the shipping box and remove the top layer of foam You see these items 1 Full Power Balanced Amplifier 1 Packet containing the owner s reference manual and the warranty registration card 2 Orient the shipping box so that one person stands at the front of the amplifier and one person stands at the rear of the amplifier Both people need to grab a pair of the card board handle cutouts one pair located at the front of the amplifier and one pair located at the rear of the amplifier and simultaneously lift the amplifier straight up out of the carton 3 Place the amplifier in a safe location and remove the protective plastic wrapping Notes If any of the items mentioned above are not included in the shipping box please contact your authorized Krell dealer distributor or Krell for assistance Save all packing materials If you ship your Full Power Balanced amplifier in the future repack the unit in its original packaging to prevent tran sit damage See Return Authorization Proce dure on page 21 for more information Placement Before you install the Full Power Balanced amplifier into your system please follow the guidelines in this section to choose its proper location This will
31. s to ground or attempt to bridge the left and right speaker binding posts of Full Power Balanced stereo ampli fiers Do not connect a Full Power Balanced amplifier to a speaker selector device that employs a common ground scheme as it may short circuit the amplifier output THERE ARE NO USER SERVICEABLE PARTS INSIDE ANY KRELL PRODUCT Please contact your authorized Krell dealer distributor or Krell if you have any questions not addressed in this reference manual This product is manufactured in the United States of America Krell is a registered trademark of Krell Industries Inc and is restricted for use by Krell Indus tries Inc its subsidiaries and authorized agents Sustained Plateau Bias III is a trademark of Krell Industries Inc and is a Krell technology based on U S Patent No 5 331 291 CAST CAST II Krell Current Mode Krell Link and Krell Playback System are trademarks of Krell Industries Inc All other trademarks are registered to their respective companies 2002 by Krell Industries Inc All rights reserved P N 305976 Contents INTRODUCTION DEFINITION OF TERMS REVOLUTIONARY KRELL CAST and CAST II TECHNOLOGY UNPACKING PLACEMENT AC Power Guidelines FRONT PANEL DESCRIPTION 700cx 400cx and 300cx Stereo Power Amplifiers 750Mcx 450Mcx and 350Mcx Monaural Power Amplifiers BACK PANEL DESCRIPTION 700cx 400cx and 300cx Stereo Power Amplifiers 750Mcx 450Mcx and 350Mcx Monaural Power Am
32. tion requirements The amplifier powers down completely and no LEDs illuminate DC present at the output stage Internal amplifier problem Contact your authorized Krell dealer distributor or Krell Contact your authorized Krell dealer distributor or Krell Krell Full Power Balanced X Series Power Amplifiers Questions and Answers Q Should leave my Full Power Balanced amplifier on at all times A For maximum amplifier performance leave the back panel power breaker switch on at all times This places the amplifier in stand by mode Full Power Balanced amplifiers are designed to be powered on and off from stand by using the front panel power button This eliminates cold start degradations The ampli fier will operate at full performance within min utes Q When turn on the amplifier there is a loud hum through the speakers What should do A When a new component is introduced a low frequency hum may occur in one or both speak ers Check all input and output connections and cables making sure they are of sound con struction See How to Troubleshoot System Noise on page 17 If the interconnects and cables are sound you may be experiencing a ground loop This can often be easily eliminat ed Please contact your authorized Krell dealer distributor or Krell for suggestions on how to solve this problem Q My system includes multiple pairs of speak ers Can connect them to my Full Power B
33. trol Operation Full Power Balanced amplifiers are compatible with the remote controls included with Krell pre amplifiers the Home Theater Standard 7 1 and the KPS 25sc Krell Playback System Please contact your authorized Krell dealer dis tributor or Krell to purchase a remote control for Full Power Balanced amplifiers Full Power Balanced amplifiers can be located in aroom or space close to the speakers but out of sight and powered on or off remotely from the listening room through a control amplifier See Krell Link Connections on page 13 HOW TO TURN OFF THE AMPLIFIER LEDs The amplifier must be in the stand by mode with the rear panel power breaker switch on While holding the silver power button in press the power key on the remote control After the amplifier finishes its turn on sequence the front panel blue LEDs turn off The blue LEDs remain off throughout normal operation as long as the amplifiers rear panel power breaker switch is not turned off HOW TO TURN ON THE AMPLIFIER LEDs With the amplifier in the stand by mode turn the rear panel power breaker switch to the off position Then turn the rear panel power break er switch back to the on position The next time the amplifier is powered up from the front panel or the remote control the blue LEDs illuminate during the turn on sequence HOW TO SWITCH BETWEEN KRELL CAST AND XLR INPUTS Press the meter key on a Krell remote to switch between CAST inpu
34. ts and the balanced XLR inputs Full Power Balanced amplifiers default to CAST operation upon startup if the amplifier is turned off from the rear panel power breaker switch and a CAST source and cable are connected to the CAST inputs The operational mode does not change if the Full Power Balanced amplifier is in stand by mode USING A DEDICATED WALL OUTLET AND SWITCH Full Power Balanced amplifiers can be powered on from an AC wall receptacle with a dedicated switch rather than from the front panel power button or optional remote control Please contact your authorized Krell dealer dis tributor or Krell for more information before you connect your Full Power Balanced amplifier to a dedicated AC wall outlet with a switch Krell Full Power Balanced X Series Power Amplifiers Amplifier Troubleshooting HOW TO TROUBLESHOOT SYSTEM NOISE AC grounding becomes critical when connect ing high performance audio components When you mix and match audio components each with its own ground potential a low frequency hum may occur in one or both speakers This often occurs when introducing a new compo nent into a system If a low frequency hum emanates from the speakers when you place the Full Power Bal anced amplifier into the system follow these simple troubleshooting steps Note During these steps the back panel power breaker switch remains in the on position 1 Check all input and output connections making sure t
35. warranty related service due to DC related damage Proof of purchase in the form of a bill of sale or receipted invoice substantiating that the unit is within the warranty period must be presented to obtain warranty service The warranty begins on the date of the original retail purchase as noted on the bill of sale or receipted invoice from an authorized Krell dealer or distributor Previously owned equipment when re purchased from an authorized Krell dealer or distributor has the balance of the original war ranty based on the original date of manufacture The warranty for Krell products is valid only in the country to which they were originally shipped through the authorized Krell distributor for that country and at the factory There may be restrictions on or changes to Krell s warranty because of regulations within a specific country Please check with your distributor for a complete understanding of the warranty in your country If a unit is serviced by a distributor who did not import the unit there may be a charge for service even if the product is within the warranty period 20 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
36. wing your speaker s specifications and exercise caution in heavy demand situations Warranty This Krell product has a limited warranty of five years for parts and labor on circuitry Should this product fail to per form at any time during the warranty Krell will repair it at no cost to the owner except as set forth in this warranty The warranty does not apply to damage caused by acts of God or nature The warranty on this page shall be in lieu of any other war ranty expressed or implied including but not limited to any implied warranty of merchantability or fitness for a par ticular purpose There are no warranties which exceed beyond those described in this document If this product does not perform as warranted herein the owner s sole remedy shall be repair In no event will Krell be liable for incidental or consequential damages arising from pur chase use or inability to use this product even if Krell has been advised of the possibility of such damages IMPORTANT The user is responsible for notifying his or her Krell deal er distributor or Krell that a tube preamplifier will be used with the Full Power Balanced amplifier so that the Krell dealer distributor or Krell can activate the coupling capac itors If the user does not notify the Krell dealer distributor or Krell and uses a tube preamplifier without the Full Power Balanced amplifier s coupling capacitor engaged Krell reserves the right to refuse

Download Pdf Manuals

image

Related Search

Related Contents

  Metabo SE12-115 Use and Care Manual  HERMA Coloured Labels A4 210x297 mm red paper matt 20 pcs.  Practical Navigation for the Modern Boat Owner  HP® LASERJET P2035 • 2055    取扱説明書 - SOOKI  VSS / VSR / VSM Single Screw Compressor  MS-01-178 R5  取扱説明書  

Copyright © All rights reserved.
Failed to retrieve file