JBL 6290, Manual

Page 1: ...NIC PRODUCTS model 6290 POWER AMPLIFIER UBL JBL Incorporated 8500 BALBOA BOULEVARD P O BOX 2200 NORTHRIDGE CA 91329 USA PHONE 818 893 8411 TELEX 4720424 SERVICE ADDRESS UREI Incorporated 8400 BALBOA B...

Page 2: ...3 2 7 4 SPEAKER 2 8 1 2 8 2 2 8 3 GROUND I MORE ABOUT LOUDSPEAKER POWER RAT SOMETIMES A LARGER AMPLIFIER CAN REMEMBER THE DIVIDING NETWORK CABLES TYPE OF WIRE DAMPING FACTOR CALCULATING LOSSES NG NGS...

Page 3: ...1 4 1 INPUT DIFFERENTIAL AMPLIFIER IV 1 4 2 MODE SWITCH IV 1 4 3 POWER AMPLIFIER IV 1 4 4 RELAY DRIVER OUTPUT DC DETECTOR IV 2 4 5 CLIP CIRCUIT IV 3 4 6 POWER SUPPLY IV 3 SECTION V MAINTENANCE V 1 5 1...

Page 4: ...ss than 25 of their rated power dissipation The benefit Is high reliability and long component life Reliable operation Is ensured through the following protection modes current Is limited under Improp...

Page 5: ...r 8 ohm stereo and 16 ohm bridge 0 2 for 4 ohm stereo and 8 ohm bridge Midband Power is maximum output power at onset of clipping both channels driven with 1 kHz sine wave THD 1 TRANSIENT INTERMODULAT...

Page 6: ...th channels 8 ohms At rated output 2000 W Both channels 4 ohms DC OUTPUT OFFSET 10 millivolts maximum DIMENSIONS 178 X 483 mm 7 X 19 In DEPTH 356 mm 14 In NET WEIGHT 28 58 Kg 63 lbs SHIPPING WEIGHT 33...

Page 7: ...lumin ated rocker type power switches Recessed stereo dual mono brIdged mono mode switch located on rear panel Individual channel clip and standby Indicators STANDBY Indicates action of output relay 3...

Page 8: ...life Additional heat producing devices should not be placed directly above or below the amplifier but at least 1 3 4 away Keep any obstructions such as wire bundles and rear mounted connector panels...

Page 9: ...can exist J B L accepts no responsibility for legal actions or for direct indirect or consequential damages that may result from violation of e I ectr i ca I codes 2 4 AMPLIFIER MODE SWITCH A recessed...

Page 10: ...s To use an unbalanced source wire the signal carrying conductor of the cable from that source to XL type pin 3 phone plug tip and wire the shield to XL type pin 1 phone plug sleeve The unused connect...

Page 11: ...sh one leg of the lug through the hole In the shaft and tighten the nut 2 5 5 ABOUT OUTPUT POLARITY AND BRIDGED MONO CONNECTION In normal stereo operation or dual mono a positive going signal applied...

Page 12: ...oducts may thus be cascaded operated in series or many inputs may be connected to a single output of a preceding device without regard to impedance matching Switching and patching is simplified becaus...

Page 13: ...eplacement fuse value and place spare fuses nearby 2 7 2 MORE ABOUT LOUDSPEAKER POWER RATINGS While there is no cut and dr i ed method to establish an appropriate amplifier power for a given speaker s...

Page 14: ...LIFIER OUTPUT A SERIES PROTECTION CAPACITOR IS STRONGLY RECOMMENDED TO REDUCE THE POSSIBILITY OF ACCIDENTAL DAMAGE TO THE DRIVER DIAPHRAGM CONSULT THE MANUFACTURER OF THE DRIVER AND HORN FOR RECOMMEN...

Page 15: ...att program signal the compression driver will be 6 dB too loud four times the level of the woofer Therefore the crossover network must provide 6 dB of attenuation for the compression driver lowering...

Page 16: ...midrange frequencies The theoretical damping factor of an amplifier may not be realized at the speaker due to added Impedance of the cable Larger gauge cables not only reduce signal losses but they In...

Page 17: ...e next thing to try Is a 3 prong to 2 prong AC adaptor between the power cord and the power outlet to temporarily unground the amplifier Try the amplifier with and without the ground strap on the barr...

Page 18: ...TO POWER THIS DEVICE THE AMPLIFIER SHOULD ONLY BE OPERATED WITH THE KNOBS OR SECURITY COVER IN PLACE high low shield 3 2 n tip ring sleeve FIGURE 2 1 BALANCED INPUT CONNECTIONS Input Signal high low s...

Page 19: ...Balanced Connection Chassis Ground FIGURE 2 3 BARRIER STRIP CONNECTIONS I 1 12...

Page 20: ...VE WAY BINDING POSTS FIGURE CHANNEL A CHANNEL B RED a BLACK 2 5 OUTPUT CONNECTIONS TO TWO CHANNEL SPEAKER SYSTEM CHANNEL A RED BLACK BINDING POSTS NOT USED FIGURE 2 6 BRIDGED OUTPUT CONNECTION TO MONA...

Page 21: ...seconds the relay will actuate as the STANDBY indicators turn off Increase the Level controls until a suitable listening level Is reached 3 2 1 A NOTE ON AMPLIFIER COOLING If the ventilation Is Insuf...

Page 22: ...signal processing and mixing equipment sensitivity describes the averaqe Input output level whereas a power amplifier s sensitivity describes the input signal required to obtain max i mum power output...

Page 23: ...hannel operates normally In the Dual Mono Channel A input is routed to both Channel A and B differential amplifiers In the Bridged Mono mode the Channel A input goes to the Channel A differential ampl...

Page 24: ...ect to ground When Q19 is ON the collector becomes approximately 0 volts and the relay turns on Current which would have gone to the STANDBY indicator is shunted by diode CR10 The relay is driven by I...

Page 25: ...the transformer is rectified and regulated to supply 15 VDC for the operational amplifiers and 24 VDC for the relay coil IV 3...

Page 26: ...st be shipped prepaid COD shipments will not be accepted For prompt service ship the unit to the factory with the RA number marked on the shipping label Use the original factory carton if necessary ca...

Page 27: ...de of each circuit board This amplifier was designed so that all of the circuitry Is accessible for probing with power on If you wish upon removal of only the top and bottom covers If a problem Is Iso...

Page 28: ...ocate power switch on right side of front panel Channel B and carefully using needle nose pliers to grasp barrel of Faston connector remove white wire white and small green wire and lower black wire R...

Page 29: ...WHITE WIRES...

Page 30: ......