Gemini-XPM1200-pwr-sm维修电路原理图.pdf

Page 1SERVICE MANUALXPM-600XPM-900XPM-1200Power AmplifersCONTENTS:Connections & Operations:.Page 2-5Specifications:.Page 6Parts Lists:.Page 8-20PCBs:.Page 21-22Schematics:.Page 23Gemini Sound Products Corp.120 Clover Place P.O. Box 6928Edison, NJ 08818-6928732-738-9003 (Phone) 732-738-9006 (Fax)RadioFans.CN 收音机爱 好者资料库17234658910111312172346589101116141517192016141518RadioFans.CN 收音机爱 好者资料库StereoMono BridgeParallel MonoPage 4Clip LED (15): the amplifier has true clip LEDs to help you properlycontrol the amplifiers output and achieve undistorted sound. The clipLEDs for each channel light when your signal level is so strong thatthe distortion reaches 1% THD. The clip LED should not remainconstantly on or flash repeatedly during operation. For clean soundreproduction, the clip should only light occasionally for an instant. Ifthe LED remains on or flashes repeatedly, you will hear distortedsound that can be damaging to your speaker systems. If this occurs,reduce the signal level by lowering the input level control for thechannel that is clipping or reduce the level at the source. If the clipLED lights when no signal is present, it may indicate a RF signal onthe output which may cause damage to speakers (the RF signal willnot be audible). Please note that when you are using the amplifier inthe Mono Bridge mode, both clip LEDs of the bridged channels willoperate simultaneously.Protect LED (16): when you first turn on the amplifier, the protect LEDslight briefly during a turn-on delay which indicates that the outputs aredisconnected internally. There will be an audible click when theoutputs reconnect and the protect LEDs will turn off. Otherwise, theprotect LED indicates that there is a problem either in the amplifiersexternal connections, load or temperature conditions or its internalfunctions. If one of these situations occur, the amplifier senses theproblem and automatically switches into protection mode. The LEDwill light to warn you of the trouble and the amplifier will stop working.If this occurs, switch off the amplifier and refer to the TroubleShooting Guide. If the protect LED remains lit when resumingamplifier operation, do not use the amplifier and contact anauthorized service technician.Level Controls (17, 18): establish the input levels required for eachchannel. Only the Channel A Level Control (17) works in MonoBridge mode.Operating InstructionsTHE AMPLIFIERS POWER MUST BE TURNED OFF WHENCHANGING MODES OF OPERATION.Stereo OperationThe unit has two channels for stereo operation. Each channelprovides a separate and discrete signal at the speaker outputs accordingto the signal received at the inputs. The following instructions are forapplications with 4 Ohm or 8 Ohm speakers of matched power ratings.1. With the power off, set the OPERATION MODE SWITCH (3) to theSTEREO position. When the power is on, the Mono and Bridge LEDson the front panel will not light. If these LEDs illuminate, you have theswitch in the wrong position. Correct before continuing.2. With the power off, connect your input cables to the channel A and Binputs using either the XLR INPUT JACKS (1, 5) or 1/4 INPUTJACKS (2, 4) of each channel. The other channel A and channel Binputs can be used to link to an additional amplifier.3. Connect the loudspeakers to the channel A and channel B SPEAKEROUTPUTS (9, 11). THE TOTAL SPEAKER LOAD MUST BE ATLEAST 4 OHMS PER CHANNEL. If you try to operate at a lowerimpedance, the amplifier will go into protection mode and stopoperation until you correct the load conditions.4. With the LEVEL CONTROLS (17, 18) of both channels set to zero(fully counterclockwise), turn the POWER SWITCH (20) on. Apply asignal to the input of the amplifier. The level of the input signal shouldbe as high as you will ever need it to be. This way, it will be as highabove the amplifiers noise floor as possible, ensuring an excellentperformance and signal to noise ratio. Adjust the LEVEL CONTROLSfor each channel to achieve the desired maximum listening level.Note, when the clip LEDs light, there is distortion present in theamplifiers output section. If a clip LED remains on or flashesrepeatedly, reduce the signal level by lowering the input level controlfor the channel that is clipping or reduce the level at the source.Connections, Controls and IndicatorsRear PanelNote: 120V and 230V units have different types of outputconnectors on the rear panel.Input Section:There are two parallel input connectors (one female XLR and one1/4” jack) per channel. Either can be used as an input or as a link tochain amplifiers.XLR Input Jacks (1, 5): electronically balanced inputs accept a standardXLR male connector. Pin 1 = shield/ground, pin 2 = hot or positive (+)and pin 3 = cold or negative (-).1/4 Phone Input Jacks (2, 4): accept a balanced as well as anunbalanced line level signal. The unbalanced line uses a standard tip-sleeve connection. The tip is positive and the sleeve is negative/ground. The balanced line uses a tip-ring-sleeve connection. Tip =hot or positive (+), ring = cold or negative (-), and sleeve = shield/ground.Operation Mode Switch (3): switch is used to set the unit for Stereomode, Parallel Mono mode or Mono Bridge mode.AC Power Section:Fuse (7): replace fuse with those of proper type and rating.Ground Lift Switch (8) is used to lift the ground from the chassis. Seethe Ground Lift Switch Instructions for more detail.AC Cord Outlet (6) is used to attach the power cord to the unit.Output Section:Disconnect unit from the AC power source before making anyconnections. Pay close attention to polarity (shown on the back of theunit) when connecting your speakers. Connecting your speaker systemsusing the wrong polarity will not damage your speakers, but it will impactthe quality of the sound (lack of bass and incorrect stereo image).Speaker Outputs for 120V Unit (9, 10, 11): the speaker output jacksare 5-way binding posts that will accept a standard banana plugs,spade lugs or bare wire. Make sure that all the connections are cleanwhen using bare wire connections. If any strands of wire from oneconnector touch the adjacent connector, the sound will be distorted,and your amplifier will overheat and go into protection mode.Speaker Outputs for 230V Unit (9, 10, 11): Neutrik Speakonconnectors are provided to connect speakers to the amplifier quicklyand easily. They are high current rated and provide very stable anddurable contacts. A third Speakon connector in the center is providedto be used if the amplifier is in the Mono Bridge mode. EverySpeakon connector has pin 1- as negative and pin 1+ as positive.NOTE: Total speaker impedance must not be lower than 4Ohm per channel for Stereo and Parallel Mono modes, or 8Ohm for Mono Bridge mode.Front PanelPower Switch (20): turns the unit on and off.Power LED (19): the power LED lights when the power is on. If thepower LED does not light, refer to the trouble shooting guide.Mono LED (12): the mono LED will light when you have set the rearpanel Operation Mode Switch (3) for parallel mono operation.Always make sure that this switch is in the correct position and thatall speaker connections have been made correctly for the mode ofoperation you wish to use before powering up the amplifier.Bridge LED (13): the bridge LED will light when you have set the rearpanel Operation Mode Switch (3) for mono bridge operation. Alwaysmake sure that this switch is in the correct position and that allspeaker connections have been made correctly for the mode ofoperation you wish to use before powering up the amplifier.Signal LED (14): the signal LEDs for each channel show when a signalis present. In Mono Bridge mode, both the channel A LED and thechannel B LED will light in unison.Page 5Parallel Mono OperationFollow these instructions for Parallel Mono Operation using a singleinput cable, and you will have the same monophonic signal on both thechannel A and the channel B outputs. Each channels output iscontrolled independently by that channels level control.1. With the power off, set the OPERATION MODE SWITCH (3) to thePARALLEL MONO position. When the power is on, the MONO LED(12) on the front panel will light. If the LED does not illuminate, youhave the switch in the wrong position. Correct before continuing.2. With the power off, connect your input cables to the channel A inputonly using the either the XLR INPUT JACK (5) or 1/4 INPUT JACK(4) of channel A. The other channel A input can be used to link to anadditional amplifier.3. Connect the loudspeakers to the channel A and channel B SPEAKEROUTPUTS (9, 11). THE TOTAL SPEAKER LOAD MUST BE ATLEAST 4 OHMS PER CHANNEL. If you try to operate at less than 4Ohms per channel, the amplifier will go into the protection mode andstop operation until you correct the load conditions.4. With the LEVEL CONTROLS (17, 18) set to zero (fullycounterclockwise), switch the power on. Apply a signal to the input.The level of the input signal should be as high as you will ever need itto be. This way, it will be as high above the amplifiers noise floor aspossible, ensuring an excellent performance and signal to noise ratio.Adjust the LEVEL CONTROLS for each channel to achieve thedesired maximum listening level. Note, when the clip LEDs light,there is distortion present in the amplifiers output section. If a clipLED remains on or flashes repeatedly, reduce the signal level bylowering the input level control for the channel that is clipping orreduce the level at the source.Mono Bridge OperationFollow these instructions to bridge the units outputs. Bridging theamplifier converts the unit to a monophonic or single channel. Theamplifier can be used with 8 Ohm or higher loads only in Mono Bridgemode. This mode is used to provide a higher voltage with greaterheadroom to your speaker. Before setting your amplifier for Mono Bridgeoperation, make sure that your speaker can handle the high power levelprovided by the amplifier in Mono Bridge mode. CAUTION: VOLTAGEOVER 100 VOLTS MAY BE PRODUCED AT THE BRIDGE OUTPUTTERMINALS IN THIS MODE.1. With the power off, set the OPERATION MODE SWITCH (3) to theBRIDGE position. When the power is on, the BRIDGE LED (13) onthe front panel will light. If the LED does not illuminate, you have theswitch in the wrong position. Correct before continuing.2. With the power off, connect your input cables to channel A input onlyusing the either the XLR INPUT JACK (5) or 1/4 INPUT JACK (4) ofchannel A. The other channel A input can be used to link to anadditional amplifier.3. Connect the loudspeaker to the BRIDGE SPEAKER OUTPUT (10)only. With a 230V unit, use the center speakon. With a 120V unit, usethe two innermost red terminals. Be sure the polarity of yourconnections is correct. The total speaker load must be at least 8Ohms or above. If you try to operate at less than 8 Ohms in the MonoBridge mode, the amplifier will go into the protection mode and stopoperation until you correct the load conditions.4. With the CHANNEL A LEVEL CONTROL (17) set to zero (fullycounterclockwise), switch the power on. Apply a signal to the input.The level of the input signal should be as high as you will ever need itto be. This way, it will be as high above the amplifiers noise floor aspossible, ensuring an excellent performance and signal to noise ratio.Adjust the LEVEL CONTROL (17) for channel A to achieve thedesired maximum listening level. Note, when the clip LEDs light,there is distortion present in the amplifiers output section. If a clipLED remains on or flashes repeatedly, reduce the signal level bylowering the input level control for channel A or reduce the level atthe source. During Mono Bridge operation, the channel B level isinactive, however, both channels LEDs will flash simultaneously andshow output conditions.Using the Ground Lift SwitchDepending on your system configuration, sometimes applying theground will create a quieter signal path. Sometimes lifting the ground caneliminate ground loops and hum to create a quieter signal path.1. With the power amp on, listen to the system in idle mode (no signalpresent) with the ground applied (the GROUND LIFT SWITCH (8) inthe left position).2. Then turn the power off before moving the GROUND LIFTSWITCH (8). Lift the ground by moving the GROUND LIFT SWITCHto the right, turn the power back on and listen to determine whichposition will provide a signal devoid of background noise and hum.Keep the GROUND LIFT SWITCH in the ground position if the noiselevel remains the same in either position.CAUTION: DO NOT TERMINATE THE AC GROUND ON THE POWERAMPLIFIER IN ANY WAY. TERMINATION OF THE AC GROUND CANBE HAZARDOUS.Page 6UNIT DOES NOT PRODUCE SOUND. POWERLED DOES NOT LIGHT. POWER SWITCH NOT IN ON POSITION. POWER CABLE NOT CONNECTED TO AMPLIFIEROR TO OUTLET. AC OUTLET NOT ACTIVE. MAIN AMPLIFIER FUSE DEFECTIVE. MOVE POWER SWITCH TO ON POSITION. CONNECT POWER CABLE TO AC SUPPLY. CHECK CONDITION OF OUTLET. REPLACE AMPLIFIER MAIN POWER FUSE ON REARPANEL WITH CORRECT TYPE AND RATING.POWER LED LIGHTS, BUT NO SOUND ISPRODUCED BY AMPLIFIER. NO INPUT SOURCE SIGNAL. INPUT SOURCE NOT CONNECTED. INPUT CONNECTING CABLE DEFECTIVE. SPEAKER(S) NOT CONNECTED. SPEAKER CABLE DEFECTIVE. SPEAKER SYSTEM(S) INOPERATIVE. AMPLIFIERS LEVEL CONTROLS ARE SET TOZERO. CHECK FOR PROPER FUNCTION OF INPUTSOURCE DEVICE. CHECK INPUT CABLES AND CONNECTIONS.REPLACE QUESTIONABLE CABLES WITH KNOWNGOOD CABLES. CHECK SPEAKER CABLES AND CONNECTIONS.REPLACE QUESTIONABLE CABLES WITH KNOWNGOOD CABLES. CHECK OPERATING CONDITION AND STATUS OFSPEAKER SYSTEM(S). BE SURE THE LEVELCONTROLS ARE PROPERLY SET.SOUND IS PRESENT BUT VOLUME IS TOOLOW EVEN THOUGH SOURCE DEVICE ISSET TO A HIGH LEVEL. AMPLIFIER INPUT LEVEL CONTROLS ARE SETTOO LOW. WRONG PIN CONNECTIONS IN CABLES. ADJUST LEVEL CONTROLS AS PER INSTRUCTIONS. USE CORRECT CABLES (AS SHOWN ON BACK OFUNIT).LOUD 50/60 HZ OR 100/120 HZ HUM ISHEARD AT ALL TIMES THROUGH THESPEAKER SYSTEMS. IMPROPER OR DEFECTIVE GROUNDCONNECTION AT INPUTS. IMPROPER ORDEFECTIVE GROUND AT INPUT SOURCEDEVICE(S). IMPROPER OR DEFECTIVE GROUNDCONNECTION ON AC OUTLET. GROUND LOOP THROUGH AC LINECONNECTION/RACK MOUNTING. CHECK FOR PROPER AC LINE GROUND ON POWERAMP AND ALL INPUT DEVICES. CHECK INPUT CABLES FOR ALL SOURCE DEVICESAND SIGNAL PROCESSING AS WELL AS INPUTCABLES TO POWER AMPLIFIER. CHECK POSITIONOF GROUND LIFT SWITCH AS PER INSTRUCTIONSFOR LIFTING THE GROUND. NEVER LIFT THE AC LINE GROUND ON THE POWERAMPLIFIER. IF YOU ARE NOT TOTALLY FAMILIAR WITHGROUND LIFTING OR UNIFICATION PROCEDURES,DO NOT ATTEMPT THEM WITHOUT FIRST CONSULTINGYOUR DEALER OR A QUALIFIED SOUNDTECHNICIAN FOR MORE INFORMATION ONGROUNDING. IMPROPERLY DONE, SUCHPROCEDURES CAN POSE A SAFETY AND/OR FIREHAZARD.SOUND IS DISTORTED. DISTORTION OCCURRING IN SOURCE DEVICE. INPUT LEVEL IS SET TOO HIGH. CHECK CLIP INDICATORS ON INPUT SOURCEDEVICES AND RESET LEVELS IF NECESSARY TOELIMINATE DISTORTION. ADJUST LEVEL CONTROLS AS PER INSTRUCTIONS.PROTECT LED REMAINS LIT OR GOES ONAND OFF INTERMITTENTLY AFTER USINGAMPLIFIER FOR A SH