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Models:
SSW-10 subwoofer Infinitesimal IV subwoofer Servo Controlled subwoofer RS Subwoofer
SERVICE MANUAL
Infinity Systems Incorporated 250 Crossways Park Dr. Woodbury, New York 11797 Rev0 12/2003
CONTENTS
SPECIFICATIONS/PRODUCT ID........................................................1 INSTALLATION/CONTROLS..............................................................2 OPERATION...................................................................................4 CIRCUIT DESCRIPTION...................................................................5 THEORY OF OPERATION...............................................................11 DETAILED TROUBLESHOOTING.....................................................18 EXPLODED VIEWS........................................................................24 MECHANICAL/ELECTRICAL PARTS LISTS........................................26 PCB DRAWINGS...........................................................................33 POWER TRANSFORMER...............................................................35 SEMICONDUCTOR PINOUTS.........................................................36 SCHEMATICS (Infinitesimal IV/SSW-10/Servo Controlled Subwoofer)......37 SCHEMATICS (RS Subwoofer)............................................... .........38 PACKING (Infinitesimal IV/SSW-10/Servo Controlled Subwoofer).............. 39
SPECIFICATIONS
Frequency Response Crossover Frequency Output Power THD (@ 75 W/100 Hz) Signal to noise ratio Input Impedance Driver Inputs Outputs Infinitesimal IV/SSW-10/Servo Controlled Subwoofer RS Subwoofer Dimensions Infinitesimal IV/SSW-10/Servo Controlled Subwoofer RS Subwoofer Weight (Infinitesimal IV/SSW-10/Servo Controlled Subwoofer) 40 - 200 Hz 40 - 200 Hz (Continuously Variable) 100 Watts (RMS) into 2 ohms < .l % > 80db 25K 10" (254mm) IMG Woofer - (DCR = 1.8 ) Line Level and Speaker Level Full Range Speaker 180 Hz High Pass Filter 13.25" x 13.25" x 13" (337 x 337 x 330mm) 23.25" x 7.25" x 13.25" (59x18.5 x 33.5mm) 34 lbs. (15.4kg)
PRODUCT IDENTIFICATION
This service manual covers the following models:
SSW-10 subwoofer Infinitesimal IV subwoofer Servo Controlled subwoofer RS Subwoofer (actually a different product, but the amplifier is nearly identical) The Infinitesimal subwoofer, Infinitesimal IV Subwoofer, SSW-10, or Servo Controlled Subwoofer may be identified from the owner's manual, outer carton or amplifier plate. It is a square black cube and is ported. Alternately, the RS Subwoofer has a distinct rectangular enclosure. The differences in the RS Subwoofer include a non-removable power cord, two high level input terminals, and a passive high-pass filter for satellite speakers (active when the high level input terminals are utilized). There is no port.
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CIRCUIT DESCRIPTION
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CIRCUIT DESCRIPTION (cont'd)
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CIRCUIT DESCRIPTION (cont'd)
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CIRCUIT DESCRIPTION (cont'd)
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CIRCUIT DESCRIPTION (cont'd)
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CIRCUIT DESCRIPTION (cont'd)
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THEORY OF OPERATION
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THEORY OF OPERATION
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THEORY OF OPERATION
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THEORY OF OPERATION
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THEORY OF OPERATION
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THEORY OF OPERATION
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THEORY OF OPERATION
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TROUBLESHOOTING the RS/SSW-I0/INFINITESIMAL IV SUBWOOFER Amplifer
We are assuming at this point the unit has been tested and there is either distortion, no output, "breathing" from woofer, it blows fuses instantly, etc. If the problem is no output whatsoever and the woofer does not react at all upon hearing the relay close, disconnect and check the DCR of the woofer with a DMM; it should be 1.7 -2.2 (to rule out a defective woofer). Another simple external problem that can be responsible for little or no output is: using the high level input terminals and having one polarity reversed on either input cable -- (the right and left signal will effectively cancel at the subwoofer input.) The relay should close (an audible "click") 2 - 5 seconds after turning on the unit. And obviously if no "click" is heard the relay has not closed and there will be no output. However whether the relay closes or not is of no consequence in the early stages of troubleshooting once the unit has been found defective. 99% of the time the relay itself is not defective. FOR ALL PROBLEMS (EXCEPT BLOWING FUSES, SEE SECTION IV): After amplifier removal from cabinet, pull back plastic cover (NOTE: plastic amp cover not present on early RS Subwoofer models) and examine PC-1 (main circuit board). It is usually not necessary to completely detach the amp cover from the amp assembly. I RELAY IS CLOSING NORMALLY (Audible "click" is heard 1 - 5 seconds after power is turned on): A. R2 & R3, 430 1watt resistors are burnt up or discolored: problem is most likely defective ICI and IC2 on PC-2 (the small input board) OR one or both of the zener diodes in the power supply. B. To check, replace R2 & R3, power up unit and check DC voltages across R2 & R3; it should be ± 11-14 VDC. If voltage is higher, remove socketed ICI and IC2 (LF347N & LF353N) on PC-2 (the small input board) or unsolder 5 - conductor ribbon attaching PC-1 to PC-2. If no change in voltage, on R2 replace ZDI, on R3 replace ZD2. If voltage is normal OR drops to normal after IC removal/unsoldering ribbon, replace ICI and IC2 on PC-2 (the small input board). If the IC's are in sockets (the latest model) it will be easy; if not the two IC's must be desoldered and removed without damaging the rest of the board. IC sockets are recommended for the new IC's. Or replace PC-2 in its entirety. (Infinity part# A021-5158) C. R2 & R3 look normal: follow instructions "B" above concerning DC voltage across R2 & R3. If all voltages are normal, replace ICI and IC2 (LF347N & LF353N) on PC-2 (the small input board A021-5158). NOTE : If PC-1 board is badly burnt because of R2 & R3 it is considered contaminated and should be replaced in its entirety. (Infinity part# A021-5152) II RELAY IS NOT CLOSING A. Follow complete instructions "B" above (RELAY IS CLOSING NORMALLY) concerning DC voltages across R2 & R3. A short in ICI, IC2, or IC3 will prevent the relay from closing. 18
TROUBLESHOOTING (cont'd)
B. If all voltages are normal: Check for +25 to 30 volts across relay terminals. (See drawing) If voltage is present, replace relay. If little or no voltage is present, check for+15 volts on pin I of IC3 (LF 347N on PC-1). Check for +2.9 to 3 volts on pin 2. Check for +12.7 volts on pin 3. Use main filter caps, (common point), or black power supply wire for ground. If any of the above voltages are abnormal: Check DC voltage across R4 (33K). (See drawing for location) Less than 50mV should be present. If higher, relay will not energize. DC is coming through the amplifier section. Check and replace semiconductors as necessary. If there is negligible voltage across R4, (normal condition) replace LF 347N IC on PC-1. RELAY CLOSING NORMALLY, BUT NO OUTPUT OR DISTORTION EXISTS Re-read or follow the instructions mentioned on the first page concerning other issues which could result in no output: (bad woofer or mis-wired high level input).
III A.
B. If those items check out, follow the signal path with schematic and DMM (oscilloscope is usually not required), checking for these approximate voltages at the points indicated below. Use main filter caps, (common point), or black power supply wire for ground: TEST CONDITIONS: Signal: l00mV @100 Hz connected to the low level input with a Y-cable (both right & left inputs). Both control pots (level and frequency) Full Clockwise. Turn UUT on. No speaker load should be connected at this time. ICI (LF347N) pin 7: 388 mV ICI (LF347N) pin 1: 392 mV Check C16 (.15µf Capacitor). One or both leads must be unsoldered for proper reading. Replace if defective. IC2 (LF353N) pin 7: 380 mV IC3 (LF347N) pin 14: 138 mV R53 (See drawing): 117mV R48 (See drawing): 2.7 volts Loss of signal at this point means Relay contacts are defective. Replace if necessary. Nominal Output at speaker cable: 2.7 volts Note: When a loss of signal occurs between amplifier stages of different IC's, it's easy to be fooled when one amplifier stage is shorted out, "loading down" the previous section of another IC. NOMINAL POT POSITIONS ON MAIN AMP BOARD -- (VR3 - Full CW), (VR4 - Half-way position) Another procedure for confining the problem to one board or the other is as follows: 1) Remove both IC's on smaller filter board (if they are in sockets), if not unsolder 5 conductor ribbon attaching PC-1 to PC-2. 2) Follow "TEST CONDITIONS" above regarding signal injection except lead should be connected to C19 (See drawing for location). 3) Turn UUT on. Output at speaker cable should be .7 - .8 VAC. If output is normal, then problem or loss of signal is on smaller filter board. 19
TROUBLESHOOTING (cont'd)
IV UNIT BLOWS FUSES INSTANTLY
Desolder, remove power supply wires from PC-1 (blue & black). Replace fuse, power up unit again. Fuse will probably not blow. If it does, see f#2. 1) Problem is usually shorted output transistor or diode semi-bridge on PC-1. These consist of: TIP 35C/36C TO-218 package BD 911/912 TO-220 package FEN 16/FEP 16 TO-220 package Recommended method to power up the unit after an output transistor replacement is with a Variac, slowly turning up the input voltage and watching a meter for high AC currents (greater than 100 mA). Occasionally the output transistors are O.K. or after a replacement, high currents will continue to appear. The problem is with one of the biasing transistors Q4, 5, 6, 7, 8, or 9. All junctions can be tested in the circuit with a "diode check" function on a DMM. If a short is found, however, remember some output devices are in parallel and will have to be removed to confirm the short. 2) Problem is a shorted toroidal power transformer. Replace if defective. RECOMMENDED FINAL INSPECTION Check for a burnt or deformed thermistor (attached to power cord plug & switch). Replace if defective. Make sure the toroidal transformer is tight and will not move easily by hand. Make sure the two (three on the older RS sub) phillips screws holding the PC-1 transistor clamp (on the front of the faceplate) are tight. Loose screws mean poor transistor heatsinking, possible premature failure. Make sure the correct line fuse is in place: 120 volt - 3A GMA slo-blo only 230 volt 1.5A GMA slo-blo only Make sure the red output wires are still maintaining an airtight seal as they thread through the plastic amp cover. Re-seal if necessary.
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SSW-10 subwoofer Infinitesimal IV subwoofer Servo Controlled subwoofer RS Subwoofer Electrical/Mechanical Parts Lists For amplifier assemblies Note: These parts lists may contain some part numbers that are not valid, or No Longer Available.
Descriptions and Reference Designators, when included, should aid technicians in part substitution.
If necessary, call the Infinity Parts department at 1-516-496-3400 ext. 6553 for assistance.
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SEMICONDUCTOR PART NUMBERS 306-0798 306-0805 306-8042 306-8043 307-8039 325-4258 325-6548 306-3891 306-3898 347-3982 347-3989 347-8024 347-8025 347-8127 2050C238900T 2050A103800T 347-8029 347-8030 347-8033 MISC. 510-8084 146-5127 870-5150 870-5354 539-5349 123-8038 545-5994 615-5141 SPEAKER SPST ITT #LZ24V RELAY LEVEL & LOW FREQ POT 20K X 2 FUSE (120V) 5 X 20mm 3A SLO-BLO GMC FUSE (230V) 5 X 20mm 1.5A SLO-BLO GMC 120V FEMALE PLUG SOCKETASS'Y w/ FUSE DRAWER 430 OHM 1 WATT RESISTORS (R2,R3) HIGH LEVEL INPUT BLOCK PLASTIC 6" POWER CORD 1N4004 DIODE 1N4148 DIODE FEP16DT DUAL DIODE FEN16DT DUAL DIODE IN5246B 16V ZENER DIODE LF347N IC QUAD OP-AMP LF353N IC DUAL OP-AMP 2N4403 TRANSISTOR 2N4401 TRANSISTOR TIP 36C TRANSISTOR TIP 35C TRANSISTOR BD911 TRANSISTOR BD912 TRANSISTOR 2SC2061 TRANSISTOR 2SC2389 TRANSISTOR 2SC1038 TRANSISTOR 2SD1763A TRANSISTOR 2SB1186A TRANSISTOR MPSA12 TRANSISTOR
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