Leslie 925 Service manual
Contents
1. CN 5 CID ss ECTS J Qe amo sir D CoD 6 CONDUCTOR CABLE 5 CONDUCTOR CABLE BASS TO TREBLE CABINET BASS TO TREBLE 061879 T lt gt 9 CONDUCTOR CABLE2. Da ELECTROLYTIC 1000 usb ELECTROLY TIC 1241247 car emm o WATE Fig 9 PARTS LIST MODEL 925 POWER SUPPLY CIRCUIT BOARD ASSY 117V 50 60Hz 059957 234 250V 50Hz 062497 Location Description EMINo Part Location Description EMI No 8 5000 MFD 50V Capacitor 022962 A2 6 8K Resistor 016501 B8 5000 MFD 50V Capacitor 022962 R63 B2 6 8K Resistor 016501 1000 MFD 35V Capacitor 023507 R64 330 ohm Resistor 016493 c5 250 25V Capacitor 024869 R65 C1 10K Resistor 028548 ES 1000 MFD 35V Capacitor 023507 R66 880 ohm Resistor 016493 D3 01 MFD 10007 20 Capacitor 060467 R67 c2 330 ohm Resistor 016493 D4 1 MFD 200V Capacitor 022251 R68 A2 6 8K Resistor 016501 D4 1 MFD 200V Capacitor 022251 R69 A1 6 8K Resistor 016501 B 200PIY 3A Diode 031450 R70 F2 330 Resistor 016493 F6 200PIV 3A Diode 081450 R71 10K Resistor 028548 B6 200PIV 34 Diode 081450 R72 330 ohm Resistor 016493 EG 200PIV Diode 031450 R73 E2 330 ohm Resistor 016493 c2 200PIV 4 SCR 080887 R143 B2 1 2K Resistor 018036 200PIV SCR 080887 R144 10K Resistor 028548 E2 200PIY 4 SCR 080387 R145 A2 180 ohm 5W 109 Resistor 023739 200PIV SCR 080887 R147 ps 22K Resistor 028530 A2 S0PIV 500MW Diode 041616 REL 1 Reed Switch 023747 200PIV 4A SCR 080387 REL 1 D3 Coil 023150 C3 400PIV 1A Diode 02505
3. OUTPUT TRANSISTORS AUXILIARY AMP BASS YELLOW 061671 ORANGE 061846 Se PREAMP AA ANG JAM CROSSOVER GREEN 059808 TREBLE AMP RED 061663 Fig 3B A 13 B 12 3 C 26 2 D 16 5 E 16 F 12 1 G 11 1 ELECTROLYTIC 50 MFD 50 V sa ow Part Location R61 R108 2111 R112 R113 R114 R115 R116 R117 R118 R119 R120 R121 R122 R1253 R146 C66 C67 C68 C71 C72 C74 C75 C82 C84 C86 C87 023 024 025 74 Preamp Crossover Network Voltages B7 C1 AT BG AS A6 AS B6 6 5 4 C1 AT A6 A6 B6 B2 B6 B1 A7 B5 CS B5 C5 Fig 4 PREAMP CROSSOVER NETWORK CIRCUIT ASSEMBLY 059808 Description 20K Potentiometer ORP 60 LDR 220K Resistor 220K Resistor 1 2K Resistor 3 3K Resistor Resistor 82K Resistor 120K Resistor 1 2K Resistor 3 3K Resistor 47K Resistor 4 7K Resistor 3 3K Resistor 150 ohm Resistor 15 ohm Resistor Poly O 1MFD 0 200V 20 Capacitor Ceramic 0047MFD 100V 10 Capacitor Mylar 033MFD 100V 10 Capacitor Ceramic 0047MFD 100V 10 Capacitor Ceramic 0047MFD 0 100V 10 Capacitor Poly 200V 20 Capacitor Ceramic 0047MFD 100V 10 Capacitor Mylar 08838MFD 100V 10 Capacitor Elect 50V Capacitor Elect 250MFD 25V Capacitor Poly O AMFD 2007 20 Capacitor Ceramic 470PF 9 1 Capaci
4. Speakers One 15 inch 4 ohm loud speaker for the Bass channel Four heavy duty 6 x 9 inch 16 ohm loudspeakers for the Auxiliary channel One 16 ohm compression type treble driver for the Treble channel Amplifiers Bass channel 50 watts output Treble channel 50 watts output Auxiliary channel 40 watts output Power Requirements 310 Watts 3 35 Amps 117 VAC 60 Hz 310 Watts 1 60 Amps 234 250 VAC 50 60 Hz Fuses 117V 60 Hz Models 2 Amp Slo Blo 234 250V 50 Hz Models 1 Amp Slo Blo A wooden unit 17 dia x 9 high Rotates at ap proximately 390 RPM in Tremolo mode approxi mately 40 RPM in Chor ale mode A black plastic unit With belt in middle pulley groove treble horn rotates at approximately 390 RPM in Tremolo mode approximately 40 RPM in Chorale mode Weight Boxed 232 pounds Unboxed 214 pounds Bass Rotor Horn GUARANTEE The speaker is guaranteed against all defects in materials and workmanship for one year from date of purchase This guarantee does not cover belts or speaker cones which may wear out soon er due to severe usage OPERATION PREPARING SPEAKER FOR USE 1 After unboxing speaker remove lower back panel from upper cabinet by undoing its two knurled mounting screws 2 Pull out the two cables stored within the up per cabinet 3 Locate cabinet connector chassis mounted in lower left hand corner lower cabinet As seen from rear of the Model 925 C
5. This belt drives the treble horn on the upper shelf upper cabinet Should the Treble drive belt become loose replace it The speed of the Treble horn may be increased or decreased by shifting the Treble drive belt to the larger or smaller di ameter grooves in the three step pulley on the large motor shaft Replacement 1 Slip old belt off the three step pulley and idler pulley 2 Lift old belt over one Treble horn then the other 3 Install the new belt reversing removal pro cedure BASS DRIVE BELT Proper drive belt tension is important An over ly tight or loose belt won t usually drive the rotor to full tremolo speed An over tightened belt may even cause excessive wear on the motor bearings With a properly adjusted drive belt the rotor should reach full tremolo speed in about 7 to 10 seconds with the belt slipping slightly on the drive pulley during acceleration Such slip page is actually necessary for attaining full rotor speed The belt acts like a torque converter As it slips the drive pulley gathers momentum and torque When the belt catches the torque in crease is transferred to the rotor causing it to rotate faster To Check Belt Tension Switch tremolo control from CHORALE to TREMOLO observing time required for the motor to reach full speed Also listen for any excessive motor noise This may indicate an over tightened drive belt To Adjust Bell Tension 1 Loosen the two motor mounting wi
6. 051607 051706 051730 055178 057778 057786 057794 059973 059981 060046 061317 061721 061879 061937 061945 061952 061986 062018 062034 062083 062281 062307 062315 062331 062364 062539 062547 063024 MECHANICAL ASSY PARTS LIST LESLIE SPEAKER MODEL 925 Description Filter Acoustic Treble Horn Grommet Spindle Treble Driver Shim Washer Flat Washer Neoprene 1 1 16 x 13 x 16 Pulley 3 Step 60 Hz Pulley 3 Step 50 Hz Nut Wing 10 24 Shoulder Bushing Grommet Bracket Z Motor Mounting Ring i Idler Assembly Idler Pulley and Bearing Assembly Idler Spring Bushing Pad Neoprene 1 x 4 x 14 Treble Horn Assembly Treble Horn Only Reflector Treble Horn Assembly Upper Rotor Support Assembly Upper Rotor Bearing Retainer Grommet Ball Bearing Rotor Lower Rotor Bearing Retainer Bushing Upper Rotor Support Lower Rotor Ball Bearing Assembly Bearing Plate Plate Belt Adjusting Screw amp Wing Nut Assembly Grommet Flat Washer 3 Pulley Motor 60 Hz Shaft amp Pulley Assembly Bushing Rubber Fuseholder Buss Motor Assembly Two Speed 117V 60 Hz Motor Assembly Two Speed 234 250V 50 Hz Motor Assembly Two Speed 117V 50 Hz Speaker 15 4 ohm Speaker Treble Driver 16 ohm Speaker Mounting Plate Treble Driver Block Shelf Key Plug 6 Pin Plug Assembly w o Mounting Speaker Assy Treble Driver 925 Flat Washer 5 16 x 34 x 1 16 Wash
7. Lubrication amp Cleaning 10 Small Motor Shaft Operation amp Adjustment 11 Motor Noises 11 Drive Belts oos niani e hern 11 Treble Drive Belt 11 Bass Drive Belt 11 Speaker Replacement 12 Treble Speaker 12 Bass Speaker 12 Auxiliary Speakers 6 x 97s 12 Bass Rotot ise case e orx ree m aa n 12 Bass Rotor Replacement 12 Bass Rotor Upper Bearing Replacement 12 Bass Rotor Lower Bearing Replacement 12 Treble Horn Lubrication Spindle Removal 18 Horn Reflector Replacement 13 Mechanical Parts List 14 Mechanical Assy Exploded View 15 Model 925 Schematic 16 Schematic 234 250 Volt Power Supply 17 Model 925 Plugs amp Sockets INTRODUCTION THE LESLIE SPEAKER MODEL 925 The Model 925 is a three channel 140 watt unit incorporating four 6 x 9 wide range loudspeak ers a heavy duty 15 Bass speaker and a heavy duty Treble Driver Model 925 may be connected to the organ with the appropriate Model 900 console connector or a Deluxe Combo Preamp Incoming signal is divided into three frequency ranges for supplying the Treble Auxiliary and Bass amplifiers This frequency division is per formed by the Preamp Crossov
8. Turn power supply upside down 2 Remove all leads attached to the circuit board Use Fig 9 as a reference when rewiring 3 Remove the four capacitor mounting screws 4 Remove the six circuit board mounting nuts Carefully slip the circuit board off its mount ing studs 925 MOTOR AND BRAKE CONTROL CIRCUITS TREMOLO CHORALE CONTROL CIRCUIT When the tremolo control is switched to CHOR ALE transistor Q10 conducts Relay 3 closes al lowing AC current to drive the slow motors AC current also passes through capacitor C63 to the base of transistor Q34 causing it to conduct Q34 acts as a switch preventing the brake circuit functioning by shorting out resistor R60 and maintaining capacitors C64 and C65 in a charged state No half wave current will flow to the fast motor of the lower two speed motor assembly when Q34 is activated See Brake Circuit ex planation below When tremolo control is switched to TREM OLO Q9 conducts Relays 1 and 2 close allowing AC current to drive the fast motors When tremolo control is switched to OFF nei ther Q9 nor Q10 conduct AC current cannot flow to the motors and the brake circuit delivers half wave DC voltage to the fast motor of the lower motor assembly for approximately 10 seconds This stops the spinning Bass rotor BRAKE CIRCUIT Because of the great momentum produced by the heavy spinning Bass rotor in TREMOLO mode a brake circuit within the dotted lines is utilized to b
9. Unsolder the black fuse wire from its present circuit board pad and resolder it to the desired primary voltage terminal as shown in the dia gram 234 250 VOLT CONVERSION YELLOW BLK 234 TRANSFORMER RIMARY RED BLACK 25 3S n3 Fig 10 MECHANICAL SERVICING MOTOR LUBRICATION AND CLEANING Usage climate and dust conditions determine motor lubrication requirements In normal ser vice yearly oiling is sufficient However if the speaker is used several hours a day more fre quent lubrication may be necessary Motors fail 1ng to start immediately may have dried up dirt clogged bearings To determine if oiling is necessary press a clean dry Screwdriver against the felt pads sur rounding the oilite bearings two in each motor If oil is transferred to the screwdriver the bear ings should not be oiled Remember over oiling 18 just as detrimental to the motors under lubrication Complete motor disassembly is unnecessary for motor cleaning A thorough cleaning job can be done with compressed air or a vacuum hose after detaching the small motor from the large motor If the motors must be completely disassembled use Figure 11 as a guide Use emery paper 3 20 grit or finer to smooth off any burrs or deep scratches on the large motor shaft before detach ing the large motor and bells This will prevent damage to the bearings within these end bells Also mark the motor mount
10. adjusted as follows 1 With speaker power on switch the Tremolo contro to CHORALE 2 Loosen the contact adjustment nuts on the small motor until small motor shaft no longer touches the rim drive wheel assembly See Fig 12 3 Grasp treble horn or rotor to prevent its turn ing 4 Slowly tighten upper adjustment nut until the small motor shaft forces the drive pulley to turn under the drive belt See Fig 12 5 Tighten the lower adjustment nut see Fig 12 against small motor laminations 6 Switch the Tremolo control between TREM OLO and CHORALE positions to check for proper shaft adjustment NOTE Make cer tain the outer edge of the O ring on the rim drive wheel is smooth If unevenness exists twist the 0 ring until it makes even con tact with the small motor shaft when small motor shaft is engaged MOTOR NOISES Excessive motor noises may indicate misaligned large motor bearings Lightly tap the large motor laminations with a hammer to reseat the bear ings OIL FELT PAD UPPER ADJUSTMENT NUT TIGHTEN TO INCREASE CONTACT LOOSEN TO DECREASE CONTACT LOWER ADJUSTMENT NUT LOOSEN TO INCREASE CONTACT TIGHTEN TO DECREASE CONTACT 12 DRIVE BELTS There are two drive belts in the Model 925 If either belt becomes worn noisy speaker operation may result A worn drive belt should be replaced TREBLE DRIVE BELT Adjustment
11. brackets and their mounting locations on the end bell before detach ing these parts Marking assures correct position ing of the brackets during reassembly TO LUBRICATE AND CLEAN MOTORS 1 Remove the motor assembly from the cabinet CAUTION Do not lose the aluminum bush ings found in the motor mount brackets 10 Detach the large motor from the small motoz by removing its four mounting bracke screws See Fig 11 Remove rim drive wheel assembly from larg motor with a 3 32 Allen wrench Saturate bearing felts at either end of thr large motor See OIL FELT PAD Fig 12 Use oiler supplied or any good grade of light machine oil Don t over lubricate Remove the shaft adjustment nut from the free end of the shaft adjustment screw See LOWER ADJUSTMENT NUT Fig 12 Remove the two nuts fastening the small motor to its mounting bracket Detach the small motor Use compressed air or a vacuum hose to re move any dust lodged in the end bells of the large motor If necessary clean small motor in the same manner WASHER FABRIC SHIM A FELT WASHER Pre STEEL WASHER FELT WASHER sih PHENOLIC WASHER IF REQ D RIM DRIVE PULLEY a SMALL MOTOR MOUNTING BRACKET SMALL MOTOR MOUNTING SCREWS FELT WASHES STEEL WASHER ZZ sms NYLATRON WASHER s 8 Clean all accessible parts wi
12. 4V 250V 50 60 Hz Belt Drive Graphited Speaker Cable 9 Conductor Cable 9 Conductor Housing Plug 6 Ckt Natural Pulley Motor 50 Hz Tubing Neoprene 1 16 x 234 Screw Machine 10 24 x 56 w Int Lockwasher Screw Machine 10 24 x 3 Screw Machine 10 24 x 214 Screw Machine 10 32 x 12 Phillips Head Screw Sheet Metal B 410 x 76 Screw Set 10 32 x 3 16 Hex Socket Cup Pt Black Oxide Washer Flat 6 Screw Machine 8 32 x 13 16 Screw Machine 8 32 x 14 Screw Machine 10 24 x 112 w Int Lockwasher Washer Flat 410 Screw Sheet Metal B 46 x 14 Hex Washer Hd Screw Machine 6 32 x 214 Washer Flat 410 Screw Machine 8 32 x 3 w Int Lockwasher Lockwasher Internal 78 Nut Hex 8 32 Screw Machine 10 24 x 7 w Int Lockwasher Nut Hex 10 32 Lockwasher Internal 410 Fuse 2 Amp 125V Slo Blo Socket 9 Contact Amphenol Lockwasher Internal 46 Socket 5 Contact Socket 6 Contact w o Mounting Plate Belt Drive 50 Hz Speaker 6 x 9 18 ohm Rotor Wood 17 x 9 Fuse 1A 250V Slo Blo Plug 6 Pin Modified Rotor Assembly Cable Assembly 6 Conductor Cable Assembly 5 Conductor 14 EMI No 050161 050211 050229 050252 050260 050500 050559 050625 050633 050641 050658 050666 050708 050716 050732 050740 050757 050807 050815 050823 051003 051029 051037 051045 051052 051060 051078 051102 051128 051201 051219 051326 051342
13. 6 REL 2 D2 Reed Switch 028747 D4 200PIV 4A SCR 030387 REL 2 D2 Coil 023150 30PIV 500MW Diode 041616 REL 3 F2 Reed Switch 023747 2 2N3414 NPN Transistor 080254 REL 3 F2 023150 AL 2 8414 NPN Transistor 080254 A4 2N4425 NPN Transistor 033563 NOTE B3 TZ525 PNP Transistor 033571 On 234 250 volt Model 925 power supplies C8 2N3414 NPN Transistor 030254 there are slight differences in the circuitry These Resistor 028555 are as follows Bi 130 ohm 5W 10 Resistor 023739 1 Capacitors C64 and C65 are now 0 1 MFD 9 47 ohm 1W 10 Resistor 040733 400V 024067 AS 130 ohm 5W 10 Resistor 023739 2 D6 7 8 9 11 and 18 are now 081997 SCR s D6 8 ohm 10W 10 Resistor 010934 rated at 400 PIV 4A A9 130 ohm 5W 10 Resistor 023739 A 1 5K 14 W 10 resistor is connected in series C6 150 ohm Resistor 024158 between the cathode of D12 and the gate of D11 15 ohm Resistor 018051 Part No 022277 pa 330 ohm Resistor 016498 4 47 ohm 14W 10 resistor is connected 10K Resistor 028548 series with C65 between C65 and the anode of D6 c3 330 ohm Resistor 016493 Part No 016311 C45 C46 not part of circuit board assembly 234 250 VOLT CONVERSIONS On high voltage versions of the Model 925 Speaker the primary of the power transformer is equipped to adapt to either 234 volt or 250 volt line current The power supply must be removed and turned upside down to make the change
14. ONTROL CIRCUITS SHOWN IN THE CHORALE POSITION 513 TRANSISTOR VOLTAGES DC 1 elel el el aT pow P ne l s REIS XA a2 o T o zo 5 16 0 46 01 i2 T o o Lus i rs 43 5 14 0 is 0 i60 o 12 ce Ts j v Pr 5 N i L L 15 50 i MODEL 925 10 P O B 33V B 28 v 8 33 L2 x lt 22 15 BASS AMPLIFIER 2N3054 913 14 17 B 33 V ahad NG B 28 V B 33V PART OF J TREBLE HORN t 2 2 YELLOW T 5 VOLTAGE DIFFERENCE BETWEEN 512 BASE AND EMITTER OF O 13 14 17 fun FOR S 22 23 24 AND P 22 23 24 8 33 B 28 V 6x9 SPEAKERS B 33 V YELLOW PART OF PART OF P24 S24 S4P4 55 P5 6x9 SPEAKERS CBE NPN Q25 24 25 MSPS 4382 515 P X 513 15 5 16 17 16 17 16 EXPLODED VI W LESLIE SPEAKER CEDi ZSAN SOHZ 250V 50H2 BOTTI OM ALLL LILL lt TREBLE CABINET BASS CABINET KALLA ZZ ZZ gt me id 4 CD 27222272777 T as Sm am lt CID ES Ceres e i G 3 15 MODEL 925 em
15. THE LESLIE SPEAKER MODEL 925 SERVICE MANUAL ELECTRO MUSIC Bin 30 Arroyo Annex CBS Musical Instruments February 1971 Pasadena Calif 91109 A Division of Columbia Broadcasting System Inc 066019 CONTENTS INTRODUCTION The LESLIE Speaker Model 925 1 Specifications 2 Guarantee a L e 2 OPERATION Preparing Speaker for Use 2 Volume Control Adjustment 2 Controls VERE 3 Auxiliary Control Circuit 3 Speaker Cable 021600 3 Multiple Speaker Installation 3 SERVICE Line Voltage 3 Ordering Parts 3 ELECTRONIC SERVICING Amplifier saa 4 Circuit Board Trouble Shooting 4 Voltage Cheeks 4 Preamp Crossover Network Voltages Parts List Parts Side 5 Treble Auxiliary Amplifier Voltages Parts List Parts Side 6 Bass Amplifier Voltages Parts List Parts Side isan ss 7 Power Supply 8 Circuit Board Maintenance 8 Motor and Brake Control Circuits 8 Power Supply Parts List and Parts Side 9 284 250 Volt Conversions 10 MECHANICAL SERVICING Two Speed Motor Assembly 10 Motor
16. acements or any other repairs involving loudspeaker disassembly Repair or replacement of loudspeaker should be arranged through a franchised LESLIE Speaker dealership CAUTION When reinstalling speaker in cabinet e er to observe correct polarity of the speaker eads TREBLE SPEAKER REPLACEMENT CAUTION Treble speaker is heavy weighing ap proximately twenty five pounds 1 Remove both backs from upper cabinet 2 Remove treble drive belt 3 Remove two 1 4 bolts with washers located on either side of the treble horn upper shelf 4 Remove idler spring wingnut Then remove the idler spring mounting screw and washer 9 Remove the other slot head screw and wash er fastening treble speaker mounting board to the shelf s underside 6 Tum treble horn so its reflectors face cabinet sides 7 Slide entire treble speaker mounting board and horn towards cabinet rear until treble Speaker clears the board upon which it rests 8 Turn treble horn so its reflectors face cabinet front and rear 9 Slide assembly out of the cabinet 10 Detach treble speaker from mounting board Remove the four Allen screws with a 3 16 Allen wrench 11 Reverse removal procedure to install replace ment speaker BASS SPEAKER REPLACEMENT Simply disconnect the speaker leads and re move the eight screws fastening speaker to the Shelf Then lift speaker straight up and out of the cabinet CAUTION Be careful not to puncture speaker cone with
17. ard hardware connectors and electronic components may be obtained locally Non stan dard items should be ordered by EMI Number through your franchised LESLIE Speaker dealer ship Speaker model and serial number would be helpful when ordering ELECTRONIC SERVICING AMPLIFIER The three channel amplifier in the Model 925 is engineered for long trouble free operation Solid state circuits are used throughout Each channel of the amplifier is mounted on a separate circuit board The circuit boards are mounted on the anodized lower back panel of the speaker cabinet which serves as a heat sink for the output tran Sistors Hereafter this lower back panel will be termed the heat sink The amplifier leads are long enough to allow the back panel to be laid flat for servicing The printed circuit boards can be removed from the heat sink and turned over without being discon nected from the circuit If a circuit board is de fective it may be easily replaced as a complete unit NOTE Shorting conductors together on an am plifier circuit board may severely damage the circuit board or its components CIRCUIT BOARD TROUBLE SHOOTING As the Treble and Auxiliary amplifiers have identical circuits it is easy to substitute one for another for testing purposes Transfer all plugs from the inoperative channel to the other circuit board If the channel functions properly after the exchange of plugs its amplifier may be de fective and the cir
18. cluded with the console connector or the four foot switches mounted on the Deluxe Combo Preamp REV AUX CONTROL OFF Opens circuit between Crossover Preamp and Auxiliary amplifier No signal to the four Auxiliary 6 x 9 speakers MEDIUM LDR light dependent resistor be comes moderately conductive driving the Aux iliary speakers at moderate volume FULL LDR conducts maximum signal to the Auxiliary amplifier and speakers Auxiliary speakers driven at full volume TREMOLO CONTROL TREMOLO Fast Actuates large motors in both two speed motor assemblies Bass rotor and treble horn spin at tremolo speed approxi mately 390 RPM OFF Brake circuit within the 925 Power Sup ply stops bass rotor and treble horn See 925 Motor Control and Brake Circuits CHORALE Slow Actuates slow motors in both two speed motor assemblies Bass rotor and treble horn spin at chorale speed approximate ly 40 RPM AUXILIARY CONTROL CIRCUIT Signal applied to the Auxiliary amplifier is controlled by an LDR light dependent resistor located in the Preamp Crossover Network Diode D1 and the Rev Aux control are part of the console connector or the Deluxe Combo Pre amp Resistors R48 R50 R51 R143 R144 R145 and Transistors Q32 and Q33 are located on the power supply circuit board Lamp M1 is located on the Preamp Crossover Network When the REV AUX control is switched to OFF current is drawn through transistor Q32 Lamp Ml is o
19. cuit board should be checked VOLTAGE CHECKS Remove the circuit board in question from the heat sink 4 nuts and fasten the black ground wire from the power supply to its ground termi nal Check the voltages on the board against the various test points indicated on the circuit board drawing The voltages given are approximate and will vary 10 under normal no signal operating conditions All voltage measurements except base and emitter voltages of 013 Q14 Q17 and Q18 Should be made between test point and ground using a 20K ohm voltmeter The bases of output transistors Q13 Q14 Q17 and Q18 should be 5 volt higher than the emitters This can measured by touching the voltmeter probes to the base and emitter of the output transistor being tested IMPORTANT Replacement output transistor s for Bass channel should be matching green blue violet or white coded transistors Use a thin smooth layer of thermal compound on both sur faces of the mica washer separating the transis tor s from the heat sink Make certain there are no air bubbles TRANSISTORS 018 COVER 023580 917 18 017 014 013 USE GRN BLUE VIOLET OR WHITE CODED TRANSISTOR ONLY MATCH 013 USE GRN BLUE VIOLET OR WHITE Ne CODED TRANSISTOR ONLY MATCH Q 14 8 32 SREW 031583 013 14 17 AND 18 ARE TRANSISTOR 2N3055 023762 Fig 3A AUXILIARY OUTPUT TRANSISTORS NOAM AY v TRANSISTORS SOCKET TREBLE 3
20. er Shim 5 16 x 34 x 1 16 Screw Cap 14 20 x 234 Hex Hd Nut Hex Coupling 14 20 x 3 x 7 L Nut Hex 14 20 x 7 16 x 7 32 Screw 14 20 x 34 Flat Hd Mounting Block Treble Driver Reducer Treble Driver Ring Pad Washer Acoustic Motor Assembly Two Speed 117V 60 Hz Motor Assembly Two Speed 117V 50 Hz Motor Assembly Two Speed 234 250V 50 Hz Gasket Speaker SCHEMATIC 234 250 VOLT 925 POWER SUPPLY BASS MOTOR gt TREBLE MOTOR o m 9 lt gt o o d 3 30 o ORG D d 4 TO R52 o 2504 m WHT TO 42 RED TO 02 d RED E YEL i R59 T BLACK REL 2 E L TO REL 2 NOTE THESE PARTS USED ONLY IN 234 250 VOLT MODEL 900 POWER SUPPLY 6 lt 10 RESISTOR PART 022277 ToQ9 471 1 2 W 10 RESISTOR PART 016311 Fig 13 MODEL 925 PLUGS amp SOCKETS 02329 O23259 RED 037127 923556 YELLOW 037085 023531 ORANGE 037135 W 023549 P 6 P 22 23 24 22 23 24 031724 RED 031732 ORANGE 039511 023531 031484 RED paige KN 031492 ORANGE 031500 YELLOW 031518 GREEN 5 13 15 16 17 P 13 15 16 17 S 7 10 11 12 P 7 10 11 12 Fig 14 17 SCHEMATIC LESLIE SPEAKER Pan 229 N 40097 M 9 a u S4 5 5 86 P6 TREBLE MOTORS BASS MOTORS SLOW C
21. er Network on the 925 heat sink The highest signal frequencies 800 Hz and above are channeled through the Treble ampli fier to power the treble driver mounted beneath the treble horn Higher frequency signal with less bass roll off powers the four 6 x 9 Auxiliary channel speak ers in the upper cabinet This channel boosts the midrange substantialy amplifying frequencies 100 Hz and above The volume of the four Auxiliary 6 x 9 Speakers can be switched between off medium and full by means of the REV AUX control pro vided with the console connector or mounted on the Deluxe Combo Preamp The lowest signal frequencies are directed through the Bass amplifier to drive the 15 bass loudspeaker mounted above the bass rotor Both the bass rotor and treble horn can be driven at fast Tremolo speed slow Chorale Speed or stopped by the two speed motor assem blies and brake circuit incorporated in the Model 925 For an explanation of the brake and motor control circuits see page 8 of this manual BLOCK DIAGRAM LESLIE SPEAKER MODEL 925 PRE AMPLIFIER amp CROSSOVER NETWORK AUXILIARY AMPLIFIER Fig 1 6 x9 6x9 OFF CHORALE TREMOLO OFF CHORALE TREMOLO SPECIFICATIONS Cabinet Finish Upper and lower cabinets are covered with Black Levant Leatherette with black grille cloth over the speaker ports Edges are trimmed in silver gray molding Cabinet Dimensions 5415 high 28 wide 2014 deep
22. ff and LDR R108 shows maximum resistance to signal flow When the REV AUX control is switched to MEDIUM D1 conducts drawing equal current between 032 and Q33 This causes lamp to glow at medium intensity Light dependent resistor R109 becomes moder ately conductive passing some signal When the REV AUX control is switched to ON only Q33 conducts causing lamp M1 to glow at maximum intensity This causes LDR R109 to pass the maximum amount of signal to the auxil lary amplifier FULL REV AUX SWITCH 4 7 B 33 V SPEAKER CABLE 021600 The 9 conductor connecting cable is supplied in a 30 foot length complete with plug and soc ket If the distance between the organ or De luxe Combo Preamp and the Model 925 exceeds 30 feet two or more 021600 speaker cables may be connected in series If specific cable length other than 30 feet is required 021618 bulk cable may be ordered in the length needed Also order 061879 plug 028837 socket and two 010322 caps for each length of bulk cable ordered to make up the Speaker cable Wire the plug and socket according to Fig 2 following the color code exactly SOCKET MULTIPLE SPEAKER INSTALLATION When requirements of volume and sound dis tribution exceed what can be obtained from one Model 925 additional speakers should be added to achieve the proper acoustical balance Each added speaker is connected by means of a 117 021709 or 234 250V 047738
23. laced If a newly installed bearing seems slightly loose remove the upper bearing support assembly from the cabinet Disassemble and bend the lower half of the bearing clamp so it will apply more pressure on the ball bearing gusgomrm BASS ROTOR LOWER BEARING REPLACEMENT See page 15 for exploded view of bass rotor assembly 1 Lay cabinet on floor so that bottom is acces sible 2 Remove the two screws that fasten the bear ing mounting plate to the cabinet and remove lower bearing assembly from the shaft Be Sure to save the flat metal washer between the rotor and lower bearing grommets 3 Remove the top half of bearing clamp to re place the ball bearing assembly 4 When re inserting rotor shaft into the bearing holder make certain the flat washer is placed between the rotor and bearing grommets TREBLE HORN See page 15 for exploded view of treble horn assembly Lubrication It is not necessary to dismantle Treble speaker assembly to oil the spindle Simply apply a few drops of LESLIE Oil or similar light machine oil to OIL HOLE in the Treble Horn TREBLE HORN SPINDLE REMOVAL 1 Remove the entire Treble Speaker Assembly from the cabinet 2 Detach the three Phillips screws attaching spindle to the treble speaker mounting plate NOTE When replacing treble horn spindle be sure to first insert the neoprene washer then the metal shim on the spindle This allows the treble horn to operate at the c
24. m 5 Wire Wound Resistor 023200 R106 A2 0 5 ohm 5W 3 Wire Wound Resistor 023200 R107 820 ohm Resistor 028373 R110 5 47K Resistor 028506 c55 A6 Poly 068MFD 250V 20 Capacitor 031393 C36 AG Ceramic 0047MFD 0 100V 109 Capacitor 028431 C57 C Elect 150MFD 25V Capacitor 031294 C58 Mylar 083MFD 100V 10 Capacitor 028654 59 B2 Poly 0 1MFD 200V 20 Capacitor 022251 C60 B4 Ceramic 0047MFD 1007 10 Capacitor 028431 Q15 A6 Transistor MSPS4382 020237 Q16 B5 Transistor 2N3054 023754 T3 B3 Transformer Driver 023788 B5 Heat Sink Q16 023663 resistors 12 W 10 unless noted otherwise 6 R88 R86 5 54772 ELLIW BLUE 430 0 5 5 Q vov Q 3 Re 9 gt 3 0 5W 5 o GREEN ge gt lt 820 1 5 ul 9 33 R83 430 0 5 5 Fig 6 Bass Amplifier Voltages L 40 4 M 3 N 1 425 P 424 Q 33 8 Note T 33 V BASS AMPLIFIER CIRCUIT ASSEMBLY Note 0 5V difference between 0 5 U V 063594 Part Location Description EMI No BG 20K Potentiometer Resistor 037648 R75 A6 1 2K Resistor 018036 R76 C 470 ohm Resistor 028068 77 AG 47 ohm Resistor 016311 R7S B4 6 8K Resistor 016501 B5 27K Resistor 020834 R80 c3 1 2K Resistor 018036 R81 1 2K Resistor 018036 R82 c5 15 ohm 1W Resistor 031823 R83 C1 430 ohm 5W 5 Wire Wo
25. ngnuts located beneath the bass speaker shelf in the lower cabinet 2 Twist the motor assembly to loosen or tighten belt as required Tighten the two motor mount wingnuts 4 Switch tremolo control between TREMOLO and CHORALE observing time required for the bass rotor to slow to chorale speed This Should take about seven to ten seconds If it does not readjust belt tension Replace Belt 1 Remove both lower cabinet backs 2 Disconnect the leads from the 15 bass speak er 3 Remove the seven screws fastening Bass speaker to the shelf Lift speaker straight up then out of the cabinet CAUTION Be careful not to puncture speaker cone with your fingers or the upper rotor support 4 Slide the exposed rotor support off the rotor Shaft 9 Slip old belt over its pulleys and remove it from the cabinet 6 Prestretch replacement belt You might feel the belt give This is normal indicating the belt has been stretched to operating length 7 Fit replacement belt onto the motor and rotor pulleys Belt should slip into belt channel in underside of bass speaker shelf 8 Replace upper rotor support bracket and the bass speaker CAUTION Be careful not to puncture speaker cone with your fingers or the upper rotor support 9 drive tension previously out ined go SPEAKER REPLACEMENT Due to the extremely strong magnetic field in the loudspeakers it is inadvisable to attempt cone repl
26. onnect cable plugs to matching cabinet connector Sockets 4 Connect cable sockets to matching cabinet connector plugs in left hand corner of the up per cabinet Replace upper cabinet back panel 5 Connect speaker cable to previously installed console connector or the Deluxe Combo Pre amp CAUTION Turn off the organ or De luxe Combo Preamp before attaching the speaker cable VOLUME CONTROL ADJUSTMENT Due to variations in speaker organ combina tions and in musical taste there are no definite volume control settings for the Model 925 925 volume controls are factory set at maxi mum volume If you desire to change the factory volume settings we recommend backing off the Master Volume Control about halfway Have someone hold a chord encompassing the organ s entire frequency range with the expression pedal on full Set the volume controls of the Auxiliary Treble and Bass amplifiers according to your musical preference These controls are adjusted through their ac cess holes in the rear of the lower back panel hereafter referred to as the heat sink Finally turn up the Master Volume Control until distortion is evident Then back it off until distortion just disappears CONTROLS The Model 925 requires two controls A REV AUX control which controls volume of the Auxili ary channel and a Tremolo control to vary the speed of the Bass rotor and Treble Horn These control functions are provided by the two switches in
27. orrect height with the possibility of thrust bearing noises eliminated HORN REFLECTOR REPLACEMENT To remove reflector clip its three stand off pins Pull pins out of their horn holes Install the new reflector with the cut edge facing upward when the horn is in operating position To hold reflector without ratling apply 3 M Weatherstrip Cement to the pins prior to insertion Then using a soldering iron melt the ends of the stand off pins to the outer horn surface to create a sturdy mechanieal bond 13 EMI No 010298 010322 011700 012526 012849 012030 013060 014019 014027 014050 014068 014084 014159 014852 014860 016816 017012 019224 020438 021048 021600 021618 023259 024307 024661 025445 025460 025528 025544 025650 025973 025981 026138 026294 026344 026518 026666 026674 026690 026740 026765 026773 026963 027953 028019 028787 028837 028993 029264 029546 030601 081062 032292 038158 040444 040469 040949 040956 Description Cable 6 Conductor w Clamp Belt Drive 60 Hz Motor Small 117V 60 Hz Screw Machine 10 24 x 114 Nut Hex 6 32 Plug 5 Pin w o Mounting Plate Motor Large 117V 50 60 Hz Wheel Rim Drive Assembly Bushing Bracket Small Motor Mounting Grommet Ring Motor Small 117V 50 Hz Motor Small 234 250V 50 Hz Bearing Assembly Treble Speaker Bracket U Screw Machine 6 32 x 56 w Int Lockwasher Motor Large 23
28. power relay avail able through your LESLIE Speaker dealer The power relay provides a source of AC power inde pendent of the organ for each added speaker The added speaker is controlled by the On Off switch at the organ or Deluxe Combo Preamp Procedure 1 Connect speaker cable to the power relay 2 Connect the power relay pigtail to the speaker 3 Plug the connecting cable for the additional speaker into the receptacle on the power relay 4 Attach speaker to the added speaker and the power relay 5 Plug the line cord from the power relay into the nearest AC outlet This procedure should be followed using an additional power relay for each speaker added SERVICE CAUTION A Extreme care should be taken to keep hands and tools away from the rotors when adjustments are made inside the speaker cabinet Because of the weight and momentum of the bass rotor there is some danger of injury to the ser viceman or to the speaker components B Attach and detach the speaker cable only after the organ or Deluxe Combo Preamp has been turned off LINE VOLTAGE Line voltage lower than 100 volts 200 volts in 234V models will result in distortion and lack of power A supply voltage in excess of 180 volts 260 volts in 234 volt models 275 volts in 250 volt models will cause overheating and possible component damage A voltage regulating device Should be used if the line voltage varies beyond these limits ORDERING PARTS Stand
29. ring the Bass rotor to a stop When tremolo control is in the TREMOLO po sition both D11 and D13 are alternately forward biased closing the fast motor circuit When the tremolo control is switched to OFF 013 becomes non conductive D11 continues to conduct however directing half wave DC current to brake the fast motor of the lower motor assem bly For approximately ten seconds this half wave DC current continues to flow until C64 and C65 are charged to peak line voltage which shuts off SCR 011 MODEL 925 POWER SUPPLY RED SI3 BLACK S8 T TRANSFORMER 030437 234 030445 ORANGE 514 RED 523 YELLOW 524 7 ORANGE sio 1 RED Si gt ja CABINET CONNECTOR ASS Y x 05993 FUSE TACT 2A 125V SLO BLO 028787 S25 CON 1 250 SLO BLO 038158 FUSE HOLDER S4 6 CONTACT 055178 060459 Fig 7 02297 MODEL 925 CONTROL CIRCUITS BASS TREBLE MOTORS MOTORS FAST SLOW FAST SLOW Part C45 C46 C47 C61 C62 C63 C64 C65 D2 D3 D4 D5 D6 D7 D9 D10 D11 D12 D13 D16 Q10 932 933 934 R48 R49 R50 R51 R54 R55 R56 R57 R58 R59 R60 WHITE W A 714 man SK _ MOLET 2 PING es 4 11 akh wa Qran LLEF xy m F copes I 22 4 NETERA G gm mang ORANGE 250 e EL so D i maman rs vm vs tn emm BM
30. th solvent Allow motors to dry 9 Saturate bearing felts at either end of the small motor See OIL HOLE Fig 12 REASSEMBLING LARGE AND SMALL MOTORS 1 Reverse disassembly procedure observing the following A Replace the neoprene O ring of the rim drive wheel assembly if it is excessively worn If rough spots exist twist O ring until the outer edge is smooth Also wipe any oil off the O ring s outer edge B When installing rim drive wheel assembly on the large motor shaft push it on as far as it will go then back it off 1 16th inch C Be sure to align rim drive wheel s set screw with the FLAT side of the large motor shaft then tighten wheel in place 2 Slip drive belt onto the drive pulley Then ad just tension of the small motor shaft as de seribed next Finally adjust drive belt ten Sion See page 11 SMALL MOTOR SHAFT OPERATION AND ADJUSTMENT The small motor drives the shaft of the large motor at slow speed by making contact with the rim drive wheel assembly See Fig 12 The small motor armature is spring loaded with drawing from the rim drive wheel assembly when the small motor is not operating Switching the Tremolo control to CHORALE activates the small motor by forcing the small motor shaft into contact with the rim drive wheel assembly thus braking the rotor to the Chorale slow speed Contact between the small motor shaft and the rim drive wheel assembly can
31. tor Ceramic 470PF 1KV Capacitor Ceramic 470PF 1KV Capacitor MSPS 4882 TSTR MSPS 4882 TSTR MSPS 1882 TSTR resistors 12 W 10 unless noted otherwise ELECTROLYTIC EMI No 037648 030379 013615 013615 018036 024141 028555 027102 027078 018036 024141 028506 028555 021141 021158 018051 22251 028431 028654 028431 028431 022251 028431 028654 025262 024860 022251 028662 028662 028662 026237 026237 026237 BLACK GND 2 R 106 ROF M F 52 swsw o 22 25 9 7 c BLUE c BLUE R 103 R107 TS 430 0 5 CAPACITOR 0657 ISOMFD 25V ELECTROLYTIC Fig 5 Treble and Auxiliary Amplifier Voltages 41 3 40 7 C 43 3 D 2 9 E 427 F Note 33 ae AUXILIARY AMPLIFIER CIRCUIT ASSEMBLY J 433 061671 E P EN TREBLE AMPLIFIER CIRCUIT ASSEMBLY between F G I K 061 663 Part Location Description EMI No R02 BG 20K Potentiometer Resistor 037648 A6 1 2K Resistor 018036 R94 C4 470 ohm Resistor 028068 R95 A5 27 ohm Resistor 021253 B 2 2K Resistor 02857 R97 B5 27K Resistor 020834 R98 1 2K Resistor 018036 R99 C4 1 2K Resistor 018036 R100 5 18 ohm 1W Resistor 031146 R101 C1 430 ohm 5W 5 Wire Wound Resistor 023648 R102 8 2 IW 59 Resistor 031807 R103 A2 430 ohm 3W 5 Wire Wound Resistor 023648 R104 AS 8 2 ohm 1W 5 Resistor 031807 R105 B1 0 5 oh
32. und Resistor 023648 R84 C1 8 2 ohm IW 5 Resistor 031807 R85 Al 430 ohm SW 5 Wire Wound Resistor 023648 R86 A3 8 2 ohm IW 5 Resistor 031807 R87 B1 0 3 ohm 5W 5 Wire Wound Resistor 023218 R88 A1 0 3 ohm 5W 5 Wire Wound Resistor 023218 R89 A5 820 ohm Resistor 028373 R90 35 17 ohm Resistor 016311 R109 A5 47K Resistor 028506 C48 B6 Tantalum 22MFD 15V Capacitor 062638 C49 Ceramic 0047MFD 100V 10 Capacitor 028431 C30 B4 50MFD 0 25V Capacitor 031294 51 Elect 083MFD 1007 10 Capacitor 028654 52 Poly 0 1MFD 200V 20 Capacitor 022251 C33 C5 Elect SOOMFD 6V Capacitor 055483 C54 A4 Ceramic 0047MFD 100V 10 Capacitor 028431 Q11 A6 Transistor MSPS 4382 026237 Q12 B5 Transistor Driver 2N3054 023754 B3 Transformer Driver 023770 B5 Heat Sink Q16 023663 All resistors 15 W 10 unless noted otherwise POWER SUPPLY The power supply is located next to the cabinet connector in the lower speaker cabinet In ad dition to supplying power for the various 925 Speaker components the power supply contains the motor control and braking circuits described later in this section POWER SUPPLY CIRCUIT BOARD MAINTENANCE It is not necessary to remove the circuit board from the power supply to check voltages and replace components Simply remove the power supply from speaker cabinet Then remove the circuit board cover from the power supply chas Sis To remove circuit board completely l
33. your fingers or the upper rotor support AUXILIARY SPEAKER REPLACEMENT 6 x 9 s Disconnect speaker leads note polarity and remove the four nuts fastening speaker to cabi net BASS ROTOR REPLACEMENT See page 15 for exploded view of Bass rotor assembly Remove both backs from the lower cabinet Remove the 15 bass speaker Remove the upper rotor support bracket Slip bass drive belt off the rotor shaft Pull the rotor shaft up and out of the Bass Rotor Remove bass rotor from the cabinet Install replacement rotor by reversing the re moval procedure Note the following A When centering rotor over the lower bear ing lift the rotor slightly and sight through the shaft hole Align the lower rotor grommet over the grommet in the lower bearing Be careful not to dislodge lower bearing s metal washer when inserting the rotor shaft B Lubricate lower bearing end of the rotor Shaft with oil or Vaseline before inserting it through the rotor The neoprene grommets are not damaged by these lubricants C The two drive pins in the rotor pulley Should straddle one of the wooden divisions be tween the cutouts in the top of the Bass rotor D Readjust Bass Drive Belt tension see Bass Drive Belt section of this manual BASS ROTOR UPPER BEARING REPLACEMENT See page 15 for exploded view of Bass rotor assembly 1 Remove Bass speaker 2 Remove top half of bearing clamp The ball bearing can now be lifted out and rep
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