ALESIS MATICA 500/900 (A4/A8) Service Manual

P/N: 8-31-0030-A

The information in this document contains privileged and confidential information. It is intended only for the use of those authorized by Alesis. If you are not the authorized, intended recipient, you are hereby notified that any review, dissemination, distribution or duplication of this document is strictly prohibited. If you are not authorized, please contact Alesis and destroy all copies of this document. You may contact Alesis at servicemanuals@alesis.com or at support@alesis.com. Copyright Alesis, LLC Confidential

Alesis Service Manual

8-31-0030-A

Preface

This document is intended to assist the service technician in the operation, maintenance and repair of the Alesis device. Together with the User Reference Manual, this document provides a complete description of the functionality and serviceability of the Device. Any comments or suggestions you may have pertaining to the document are welcome and encouraged. READ THIS!
In addition to any purchase price that Alesis may charge as consideration for Alesis selling or otherwise transferring this service manual (Manual) to you, if you are not a service and repair facility (Service Center) authorized by Alesis in writing to be an authorized Service Center, Alesis sells or transfers the Manual to you on the following terms and conditions: Only Service Centers authorized by Alesis in writing are authorized to perform service and repairs covered by an Alesis warranty (if any), and transfer of the Manual to you does not authorize you to be an authorized Service Center. Therefore, if you perform, or if the Manual is used to perform, any service or repairs on any Alesis product or part thereof, any and all warranties of Alesis as to that product and any service contract with Alesis for that product shall be voided and shall no longer apply for such product, even if your services or repairs were done in accordance with the Manual. All service or repairs done by you or with reference to the Manual shall be solely your responsibility, and Alesis shall have no liability for any such repairs or service work. All such service or repairs are performed at the sole risk of the person performing the service or repairs. You agree that all such work will be performed in a competent, professional and safe manner at all times and to indemnify and fully hold Alesis and its successors and assigns harmless in the event of any failure to so perform. Your purchase of the Manual shall be for your own ultimate use and shall not be for purposes of resale or other transfer. As the owner of the copyright to the Manual, Alesis does not give you the right to copy the Manual, and you agree not to copy the Manual without the written authorization of Alesis. Alesis has no obligation to provide to you any correction of, or supplement to, the Manual, or any new or superseding version thereof. Alesis shall have the right to refuse to sell or otherwise transfer repair parts or materials to you in its sole discretion. You shall not use, sell or otherwise transfer spare or replacement parts supplied by Alesis to you (i) to repair or be used in products manufactured for or by third parties or (ii) to any third parties for any purpose. You shall not make any warranties or guarantees with respect to the products of Alesis or the use thereof on behalf of Alesis or in your own name. The foregoing describes the entire understanding related to sale or transfer of the Manual to you, and no other terms shall apply unless in a writing signed by an authorized representative of Alesis. All Trademarks are property of their respective companies.

Confidential

Warnings
TO REDUCE THE RISK OF ELECTRIC SHOCK OR FIRE, DO NOT EXPOSE THIS PRODUCT TO WATER OR MOISTURE. The arrowhead symbol on a lightning flash inside a triangle is intended to alert the user to the presence of un-insulated "dangerous voltage" within the enclosed product which may be of sufficient magnitude to constitute a risk of electric shock to persons. The exclamation point inside a triangle is intended to alert the user to the presence of important operating, maintenance and servicing instructions in the literature which accompanies the product. REPAIR BY ANY PERSON OR ENTITY OTHER THAN AN AUTHORIZED ALESIS SERVICE CENTER WILL VOID THE ALESIS WARRANTY. PROVISION OF THIS MANUAL DOES NOT AUTHORIZE THE RECIPIENT TO COMPETE WITH ANY ALESIS DISTRIBUTOR OR AUTHORIZED REPAIR SERVICE CENTER IN THE PROVISION OF REPAIR SERVICES OR TO BE OR MAKE REPAIRS AS AN AUTHORIZED SERVICE CENTER. ALL REPAIRS DONE BY ANY ENTITY OTHER THAN AN AUTHORIZED ALESIS SERVICE CENTER SHALL BE SOLELY THE RESPONSIBILITY OF THAT ENTITY, AND ALESIS SHALL HAVE NO LIABILITY TO THAT ENTITY OR TO ANY OTHER PARTY FOR ANY REPAIRS BY THAT ENTITY.
Regarding the Power Supply Fuse
CAUTION: The product under service may employ the use of a replaceable fuse. Danger of fire or electrocution if fuse is incorrectly replaced. Replace with only the same type or equivalent type recommended by the equipment manufacturer.
Regarding the Internal Battery
CAUTION: The product under service may employ the use of a internal battery. Danger of explosion if battery is incorrectly replaced. Replace only with the same or equivalent type recommended by the manufacturer. Dispose of used batteries according to the manufacturer's instruction.

Safety Instructions

Carefully read the applicable items of the operating instructions and these safety suggestions before using this product. Use extra care to follow the warnings written on the product itself and in the operating instructions. Keep the operating instructions and safety suggestions for reference in the future.

Alesis A4/A8 Service Manual------

03/07/03

Table of Contents PREFACE.... ii WARNINGS.... ii SAFETY SUGGESTIONS... iii General Troubleshooting...iv 1.00 Theory of Operation.... 1 1.10 Input Section... 1 1.20 Pre-Amp Section... 2 1.30 Main Amplifier Section... 2 1.40 Output Device Protection... 3 1.50 Bias Circuit... 3 1.60 Speaker Protection... 4 1.70 Fan Speed Control... 4 1.80 Thermal Management System... 5 2.00 Updates and Corrections... 5 2.10 Stripped Heat Sinks.. 5 2.20 New Case Bracket Insulator(s).. 7 2.30 Transformer Insulators... 8 3.00 Troubleshooting.... 9 4.00 A4 Service Parts List... 10 4.10 A8 Service Parts List... 13 5.00 Service Manual History.... 16 INDEX.... 17

1.00 Theory of Operation

The A4/A8 amplifiers are basic stereo amplifiers. They have 0dBm input sensitivities for rated output at 4 , with the ability to drive any load impedance from 2 to an open circuit. They have balanced inputs via Neutrik combination connectors providing XLR and 1/4" TRS connections and also a barrier strip. The output of the amplifier is obtained by way of four five way binding posts. Reference designations in the text refer specifically to the A4 amplifier except where otherwise noted. Though reference designations between the two units are different, the designs are virtually identical. The only significant differences occur in the output section (since the A8 is required to handle much more power than the A4). Here are some of the major features and building blocks of the Matica: An input balanced to unbalanced converter. A second stage pre-amp and an amplifier gain stage utilizing a monolithic front end with discrete complimentary transconductance stage and a complimentary output stage in a common collector configuration. Output device protection is accomplished with a conventional volt-amp current limiter circuit. The output devices use a new perforated emitter technology unique to MOTOROLA. The output devices are driven by similar technology devices, but they have been optimized for extremely linear current gain with a unity gain bandwidth (Ft) of 50 MHz. The speakers are protected by output relays. They are activated during the first 3 to 5 seconds the amplifier is turned on. Also, if a DC condition exists at the output of the amplifier or the amplifier is driven to full output below 5Hz the relays will be activated. Thermal management and protection are accomplished with a large heavy aluminum extruded heat sink the is fan cooled. If the sink gets warmer than 55 deg. C, the fan is automatically stepped up in speed and if the heat sink gets warmer than 80 deg. C the fan is run at high speed and the output relays are activated to disconnect the load until the unit has cooled to 65 deg. C. There is also a unique feature of the amplifier fan circuit in that when the amplifier is providing an output signal of a little more that a watt the fan speed is modulated or increased by the signal. This will help get longer run times with the amplifier under extreme load conditions. 1.10 Input Section The input stage is made up of a dual Signetics 5532A op amp. This is a low noise selected version of the 5532. One half of the dual is used for each channel. The circuit is a basic balanced to unbalanced converter. It can be driven unbalanced but 6dB differences in gain may result for various hookups. If the (+) input is driven with the (-) input grounded the gain will be unity. If the (+) input is driven with the (-) input left open there will be a gain reduction of 6dB. This is not recommended as a noisier condition may result. If the (-) input is driven, gain will be unity and will not change with the grounding or ungrounding the (+) input The maximum input level before clipping in about +21dBm. Since there is no level control in front of the converter this is the maximum input level for the amplifier. Connections to the Alink connector are between R1, R2 and R3, R4. These are provided so an outboard impedance may be connected to modify the gain and overload characteristics as well as its frequency response. Following the amplifier is a passive low pass (R7, C1) filter that begins to limit the high frequency gain of the amplifier.

Alesis A4/A8 Amplifiers Service Manual------
1.20 Pre-Amp Section The pre-amp section also uses the Signetics 5532A op amp. The circuits of the pre-amp are of opposing signal polarity to provide push pull characteristics and are connected via the stereo/bridge switch. Each of the two pre-amp channels has 15.7 dB of gain but channel A is inverting and channel B is not. Since the main amplifier is inverting, channel A will not invert the signal and channel B will. Doing this facilitates two things. When the stereo/bridge switch is in the bridge mode channel B will already be out of phase with A so no signal inversion will have to be done to achieve bridge operation. Also by operating B out of phase all the time, (even in stereo operation) getting the phase of the signal flipped back at the speaker terminals, the amplifiers low frequency power bandwidth will be increased. This allows the power supply to be utilized more efficiently. This section also shapes the bandwidth of the amplifier further via another low pass pole being added to each stage. First and second stage high pass filtering occurs via the 100uf coupling capacitors preceding the volume pots and after the pre-amp stages. The pre-amp stages drive the main amplifier directly. ALINK connections at the junction between R8, C2 and R13, C5 are for sending the output signal of the input stage at a low impedance for use with auxiliary equipment. The connection between R9, R10 and R14, R17 are to be used to for defeating the level controls by supplying an input signal from a very low source impedance to swamp out the signal from the pots. 1.30 Main Amplifier Section The main amplifier is composed of four sections: The monolithic front end. A complimentary voltage gain stage or transconductance stage The output driver The output stage The amplifier is configured in the inverting mode. This allows for the inputs of the op amp to remain at a 0 voltage potential and ease operation on a +/- 15 volt supply. The large voltage swing is accomplished with a discrete, complimentary darlington connected transconductance stage Q1, Q2, Q3, and Q4. The current in the transconductance stage is set by the voltage divider network made up of R19, R20, R21, and R22. The first transistor in the darlington is a TO-92 packaged device with the current set by R27, and R28. The collector of this transistor is not tied to the second collector in the darlington connection but rather to the +/-15 volt supply to help increase the bandwidth of the stage and reduce the dissipation in the TO-92 devices. The closed loop gain of the amplifier has been set for 10X or 20dB. The DC output offset is a function of the input offset voltage error of the op amp times the gain of the system. With the offset error of the op amp at about +/- 1mv the amplifier will have less than +/- 10mv of output offset. The feedback network is composed of R25, R18, and C11. C11 reduces the bandwidth of the amplifier. The large low frequency gain of the op amp helps to reduce the supply ripple that is introduced into the system by the lack of supply rejection in the voltage gain stage. Under driven conditions at mild loads of 4 or 8 at mid and high frequencies, the output of the op amp will appear not to have any signal or very little signal on it. When the amplifier is clipped, or driven to its rail, the output of the op amp will be driven to its rail, or about +/- 14 volts. It is trying to correct the loop error or non linearity of clipping in the amplifier. The only other time the output of the op amp will become a large signal is at a 2 condition at lower frequencies. This is due to the loss of loop gain when the transconductance stage is required to deliver large amounts of current to the output stage drivers. CR1 and CR2 are connected as clamps to the discrete

darlingtons (causing the transconductance stage not to saturate, which reduces the possibility of saturation in the gain stage). The drivers and output devices are mounted on the large extruded aluminum heat sink. The drivers have extremely linear gain with changes in current. They also have an Ft of 50mHz keeping the gain linear with frequency. The output devices are 16 amp, 250 volt, 200 watt devices. These are very strong devices. The output stage is configured in a common collector, or emitter follower configuration. The drivers are connected again in a discrete complimentary darlington configuration. This allows for a class A bias and protection scheme that offers very close bias tracking and simple current limiting. Also there are 1.2 resistors in the bases of all the output devices. This helps linearize the gain with frequency and reduce high current parasitics. When the output stage is biased properly, the DC voltage drop across the emitter resistors should by 2-3mv cold and may rise to as much as 6-10mv when hot. Finally the output of the amplifier is de coupled from the load with a traditional termination network. This network isolates the amplifier and feedback loop from loads at high frequencies, especially capacitive ones. This is how unconditional loop stability is achieved. Under bench test conditions it is recommended that the amplifier not be driven to full power at 20kHz and above for periods longer than a few minutes as this will cause R53 to over heat. Under music conditions there is never enough energy to have this be a problem. 1.40 Output Device Protection Output device protection is accomplished with a relatively simple circuit. The protection circuit is broken up into Q17 that protects the NPN output devices and Q18 that protects the PNP output devices. These devices are complimentary as are the output devices but they also have similar Vbe N to P. This allows selection of a point of protection that will be about equal for each half of the output stage. R55 and R56 sense the voltage at the emitter of two of the output devices and sum them. The emitter of Q17 is connected to the output of the amplifier. When a voltage across the emitter resistors of the output devices reaches about 0.7 volts, Q17 will conduct if there is no voltage across R54. This condition exists for a short circuit or something very close. As the amplifier impresses a voltage across a load it also has that same voltage across R54. As the voltage across R54 gets larger more current must flow through the emitter resistors of the output devices to cause enough voltage to be developed at the base of the protection device to turn it on. This is what is known as the load line. As the voltage across the output devices gets lower they can deliver more current in keeping with a constant power. When the protection device is conducting the current from the transconductance stage is essentially being diverted around the output stage to the load. Everything described for the positive half cycle is the same for the negative half. C18 and C19 slow down the protection device and keep it from any possible oscillation condition. CR3 and CR4 are used to protect possible reverse Vbe conduction of the protection devices and CR4 and CR5 prevent conduction of the protection devices while in the opposite half cycle. 1.50 Bias Circuit The bias circuit is more that just a single device Vbe multiplier seen in many audio amplifiers. The circuit consists of an active shunt regulator. The reason for this is two fold. The shunt regulator has a much lower impedance than the single device regulator. This helps control the bias voltage better when there is a change in the quiescent operating current of the transconductance stage. Since the operating, or quiescent current of the transconductance stage is supply dependent, the need for a bias circuit that doesn't change voltage with current is imperative. Also by reducing the current through the bias sense transistor a larger change in Vbe with temperature can be realized. This tracks the needs of the output stage better. The 5k pot in the bias circuit adjusts the potential of the regulator. A 1.5k resistor (R55) sets the current Alesis A4/A8 Amplifiers Service Manual-----3 03/07/03

speed will still be modulated by the drive to the amplifier. If the heat sink gets hot enough to trip the 80deg. C. breaker, then the relay circuit will disconnect the load and also turn on Q25 and Q26. This will increase the fan to its highest speed and cool the amplifier. Upon cooling below 65deg. C. the amplifier will resume normal operation. 1.80 Thermal Management System The large extruded aluminum heat sink in the center of the chassis is the heart of the amplifiers heat dissipation scheme. It is a forced air cooling system. In the A8 the heat sink has a thermal resistance of.075 deg. C. per watt when the fan is at full speed. This is equal to about 800 watts of heat. The air from the fan is forced into the center of the side of the heat sink with fins and the air flows around the sink and out over the amplifier circuitry. It has an air intake at the front of the amplifier and exhaust at the left rear. As explained in the fan speed control section, the speed of the fan is determined by the demands on the amplifier. If for some reason the fan should stop but not fail there is enough dissipation in the main heat sink as well as the four TO-220 stand up heat sinks on the PCB to allow operation indefinitely while at a quiescent condition.
2.00 Updates and Corrections.
2.10 Stripped Heat Sinks Occasionally when tightening down the heat sink clamps one of the screws will strip the threads out of the heat sink itself. Because heat sink is a rather expensive and bulky item, a way was found to reuse stripped heat sinks. Use a long (at least 1 1/4") machine screw from the clamp side, and a threaded hex standoff inserted into the heat sink fin side. Do not use just a hex nut, as it will probably not be able to hold the clamp pressure any more then the heat sink did. See diagram on next page.
2.20 New Case Bracket Insulator(s) It was found that it was possible for the insulation on the wires from the main power transformer(s) could over time be cut by the case bracket(s) (one in A4, two in A8). This could in turn make it possible for the end-user to be shocked through the case itself. The solution was to replace the insulators with a version that covered those areas of the metal that could potentially cut the insulation. To replace the old insulators, first remove the rectifier and move the Figure 2 Bracket, Regulator, and Mounting Screw cables away from the case brackets. Locations Be sure to examine the wires for any damage that have already occurred. Then remove the bracket(s) from the chassis. Figure 2 shows the locations of the bracket mounting screws while Figures 3 and 4 show the new and old styles of insulator (New style Alesis Part # 5-04-1018). Replace the old insulators and reassemble the brackets and rectifier. Route the wires around the transformer bracket(s) as shown in Figure 5. In addition, the regulator U5 (A8) U4 (A4) and transistor Q53 (A8) Q39 (A4) on the Fan PCB (See Figure 2) should be checked to ensure that they do not short to the case. If necessary, bend these components away from the case bottom and resolder both of them to ensure a solid connection.

FINAL ASSEMBLY FAN MAIN B+ BJ1 TO J14 MAIN J2 to J14 (GRAY) J23 TO J20,J13,J8,J3 J12 TO J19 (YELLOW,GRN,BLUE) J15 TO J21 (BRN,RED,ORANGE)
FAN MAIN MAIN FAN MAIN FAN MAIN FAN FAN MAIN MAIN OUTPUT M FAN MAIN FAN MAIN MAIN MAIN FAN MAIN FAN FAN MAIN MAIN OUTPUT M MAIN FAN FAN MAIN OUTPUT FAN OUTPUT FAN MAIN MAIN MAIN FAN FAN MAIN MAIN FAN MAIN OUTPUT MAIN PCB OUTPUT M
C39 C 19, 49 C 2, 3, 16, 30 C42, 43 C 9, 11, 14, 18, 20, 21, 23, 25, 28, 32, 33, 34 C38, 47, 48, 50 C6 C44 C45, 46 C 10, 12, 24, 26 C 4, 7 C35, 36 C37, 40 C 8, 13, 22, 27 C41 C 1, 5, 15, 17, 29, 31 CR 4, 5, 11, 12 CR 3, 10 CR18,26 CR 6-9, 13-16 CR 17, 19, 20, 22-25 CR21 CR 1, 2 R30, 32, 57, 83,86, 89 R93, 96, 99, 104, 107, 109 R 23, 59, 90, 91 R128 R137, 138 R 29, 31, 56, 82, 85, 88 R94, 97, 100, 105, 108, 110 R114 R92, 111 R112 R 9, 11 R 3, 6, 14, 17, 45, 53, 71, 79 R 12, 13 R116, 123, 125-127, 130, 131, 133-135 R113 R 22, 28 R 136 R121, 122, 132 R33, 58, 84, 87 R95, 98, 103, 106 R 7, 18, 36, 49, 62, 75 Ref.Designator R101, R102

Comment

CFR CFR CFR CFR CFR CFR CFR CFR CFR CFR CFR CFR CFR CFR CFR CFR CFR CFR CFR CFR CFR CON CON CON CON HDR HDR HDR HDR HDR HDR HDR HDR HDR HDR HDR HDW HDW HDW HDW HDW HDW HDW HDW HDW HDW HDW HDW HDW HDW HDW HDW HDW HDW HDW HDW IC JAC LED LED LIT Group LIT ME ME
0-99-0563 0-99-0593 0-99-0680 0-99-1000 0-99-1000 0-99-1001 0-99-1001 0-99-1402 0-99-1500 0-99-1500 0-99-2210 0-99-3033 0-99-3300 0-99-3300 0-99-3303 0-99-4990 0-99-4991 0-99-4992 0-99-5001 0-99-7682 0-99-9092 4-10-0007 4-10-0007 4-98-0003 4-98-0004 4-15-2002 4-15-2003 4-15-2003 4-15-1002 4-15-1002 4-15-1006 4-15-1006 4-15-1008 4-15-1008 4-15-1014 4-99-0026 5-00-0076 5-00-0077 5-00-0078 5-00-0079 5-00-0085 5-00-0086 5-00-0088 5-00-2006 5-01-0020 5-01-0022 5-02-0005 5-04-0016 5-04-0017 5-04-0018 5-04-0019 5-04-0022 5-04-0023 5-05-0001 5-07-0005 5-07-0005 2-22-1339 4-05-0007 3-99-0001 3-99-0002 7-51-1107 Part.Number 7-53-0001 7-03-0006 7-06-0004
RES 5.6K 1/2W 5% CF RES 59K 1/4W 1% MF RES 680 OHM 5W 5% WIRE WOUND RES 1K OHM 1/4W 1% MF RES 1K OHM 1/4W 1% MF RES 1K OHM 1/2W 5% CF RES 1K OHM 1/2W 5% CF RES 1.40K OHM 1/4W 1% MF RES 1.5K OHM 1/4W 5% CF RES 1.5K OHM 1/4W 5% CF RES 2.21K OHM 1/4W 1% MO RES 0.33 OHM 1/4W 5% METAL OXIDE (FLAMEPROOF) RES 3.3K 1/4W 5% CF RES 3.3K 1/4W 5% CF RES 330K 1/4W 5% CF RES 4.99K 1/4W 1% CF RES 499 OHM 1/4W 1% MF RES 49.9K OHM 1/4W 1% MF RES 5K LINEAR TRIM POT RES 7.68K OHM 1/4W 1% MF RES 9.09K OHM 1/4W 1% MF CON BINDING POST A4, A8 CON BINDING POST A4, A8 STRIP BARRIER (5-POS) DT-55-B-14N-05 TAB FASTON 1/4" (AMP 62650-1) HEADER 2-PIN SIL 0.1 SPC LOCKING (AMP 640456-2) HEADER 3-PIN SIL 2MM CTR (SHROUDED) HEADER 3-PIN SIL 2MM CTR (SHROUDED) HEADER 2-PIN SIL 2mm SPC (shrouded) HEADER 2-PIN SIL 2mm SPC (shrouded) HEADER 6-PIN SIL 2MM CTR (SHROUDED) HEADER 6-PIN SIL 2MM CTR (SHROUDED) HEADER 8-PIN SIL 2MM CTR (SHROUDED) HEADER 8-PIN SIL 2MM CTR (SHROUDED) HEADER 14 PIN SIL 2mm SHROUDED HEADER 26-PIN DIL.100 SPC SCREW 6-32 x 3/8 TAP TIGHT THREAD ROLLING PAN HEAD TROX BLK SCREW 10-32 x 5/16 TAP TIGHT THREAD ROLLING PAN HEAD TROX BLK SCREW 6-32 x 1/2 TAP TIGHT THREAD ROLLING PAN HEAD TROX ZINC SCREW 10-32 x 7/8 TAP TIGHT THREAD ROLLING PAN HEAD TROX ZINC SCREW 8-32 x 1/2 #6 PH TAPTITE TORX BLACK OXIDE W/WAX SCREW M3 x 6MM PPZ MACHINE SCRW,6-32x3/8 PPH THRD LNGR CAD SCREW, JACK, 3/16 X 1/4 WASHER #10 FLAT SPLIT RING RING RETAINING F/P A4/A8 STANDOFF,.400,24AWG,PVC TUBING FASTENER STUD RECEIVER (PUSH-ON) SPACER LED (LTM-480) WASHER #10 FLAT BRASS WASHER.140 ID x.375 OD x.047 VFP SPACER #10 x.125 INSULATOR TO220 SIL-PAD A4/A8 CLIP STRAIN RELIEF HEYCO 1207 SPACER PCB 5/16 x 1/4 NYLON (RICHCO SSRS-8-4-01) SPACER PCB 5/16 x 1/4 NYLON (RICHCO SSRS-8-4-01) IC LMT339N QUAD COMP (MOT) JACK XLR + 1/4" FEMALE LED RED HIGH EFF (LED TECH LT5241R) LED GREEN (LED TECH LT5221) MANUAL REFERENCE A4/A8 Description STICKER BUMPER BRIDGE CM3502 35AMP/200V RELAY SPST 901CS-DC12

1 Qty 2

MAIN MAIN MAIN MAIN FAN MAIN FAN MAIN MAIN FAN MAIN MAIN MAIN FAN FAN MAIN MAIN MAIN MAIN MAIN MAIN
R 54, 80 R 41, 46, 67, 72 R 24, 25 R 35, 48, 52, 61, 74, 78 R120 R 10 R129 R 42, 68 R 51, 77 R124 R 34, 47, 60, 73 R 26, 27 R 55, 81 R117 R115, 118, 119 R 1, 2, 4, 5, 15, 16, 20, 21 R 8, 19, 43, 44, 69, 70, 139, 140 R 38, 64 VR 1, 2 R 39, 40, 66 R 65 Final Assembly J5 P1-22 J22 J 1, 12, 14, 15 J19, 21 J 3, 9, 10, 13 J20 J16 J 17 J 2, 8 J 18 J23 J6 COVER AND MTG 8 TRANSFORMER MTG AND AC GND BINDING POST BRIDGE RECTIFIER HEATSINK ASSY/TRANSISTOR CLAMP COMBO CONNECTOR REAR PANEL REAR PANEL AC GROUND SCREW FRONT PANEL FASTENER E AND C LEADS OF Q31,Q36 DS 1-3 BRIDGE RECTIFIER PCB MTG SPACERS ADD TO THERMALLOY HEATSINK Power cord MIG 1-3 MIG 5-7 U5 J 4, 11 DS 1,3 DS 2 LITERATURE PACK Ref.Designator BR1 K1,2
REPLACED BY 9-96-1259 ASSY.
MAIN FAN FAN MAIN OUTPUT M MAIN OUTPUT M MAIN CONTROL MAIN CONTROL FAN MAIN

CONTROL

MAIN MAIN OUTPUT FAN MAIN CONTROL CONTROL PCB

Relay MUST be 'C'-config

ME ME ME ME ME MIS MIS MIS MIS MIS MIS MIS MIS MTL MTL MTL MTL MTL MTL MTL MTL MTL PLS PLS PLS PLS PLS PLS POT RES RUB RUB SWT SWT TRN TRN TRN TRN TRN TRN TRN TRN TRN TRN TRN TRN TRN TRN WIR WIR WIR WIR WIR WIR WIR WIR WIR WIR WIR Group
7-06-0008 7-06-0010 7-06-0011 7-10-0029 7-20-0015 5-04-0000 5-04-1018 7-70-0001 7-70-0006 7-70-0008 7-70-0010 7-90-0007 9-23-1058 9-03-1145 9-03-1147 9-03-1149 9-03-1151 9-03-1152 9-03-1154 9-03-1156 9-03-1157 9-03-1164 5-10-1008 9-15-0040 9-15-0095 9-15-1189 9-15-1190 9-15-1194 0-09-1037 0-00-0000 9-23-1056 9-23-1057 6-01-0002 6-02-1500 2-03-0006 2-03-0006 2-03-0006 2-03-0056 2-03-0650 2-03-0650 2-03-0750 2-03-0750 2-03-1193 2-03-1194 2-03-1302 2-03-3281 2-04-1837 2-07-4793 4-19-1404 4-19-1405 4-19-1407 4-19-1408 4-19-1413 4-19-1414 4-19-1415 4-19-1416 4-19-1419 4-19-1420 4-19-1421 Part.Number 2-99-0031 2-99-5532 2-99-7815 9-23-1068
CIRCUIT BREAKER 28-XQ1A-12 BREAKER THERMAL CUTOUT 80 DEG.O.O.R. BREAKER THERMAL CUTOUT 55 DEG. C.O.R. FAN,DC ST12N6X INDUCTOR,AIR CORE 1uH INSULATOR, RECTIFIER 1.250X1.250.200 HOLE INSULATOR XFMR BRACKET FISH PAPER 6x5 FISH PAPER 10.0 A4 FISH PAPER 1.5 x 9 A4 INSULATOR, FELT DISC.375 DIA. X.032 TWIST TIE,PLASTC WIRE 7" INSULATOR FOAM A4, A8 CHASSIS A4 COVER TOP A4 BRACKET TRANSFORMER A4/A8 CLAMP TRANSISTOR A4/A8 HEATSINK EXTRUSION,150 inch stick (REV C.) HEATSINK A4 HEATSINK THM7022B-MT CLIP HEAT SINK CLP-201 HEATSINK RECTIFIER 3 x 1.250 x.125 TIE WRAP 3.250 BLACK PLASTIC RICHO (WIT-18SF-BK) KNOB 35MM PA INSULATOR K6 A4 PANEL FRONT A4, A8 LABEL A4 F/P LOGO BLOCK BINDING POST A4,A8 POT 5K SINGLE W/RIGHT ANGLE LEADS RES 0 OHM 1/8W 5% FASTENER FAN (A4 A8) FEET RUBBER.30 x.81 BLK (3M SJ5023) SWITCH SLIDE DPDT SWITCH SPST 16A POWER 1500H11E TRANS MPSA06RLRA TRANS MPSA06RLRA TRANS MPSA06RLRA TRANS MPSA56RLRA TRANS MPS650RLRA TRANS MPS650RLRA TRANS MPS750RLRA TRANS MPS750RLRA TRANS MJL21193 TRANS MJL21194 TRANS MJL1302A TRANS MJL3281A TRANS 2SA1837 TRANS 2SC4793 WIRE 3.75" BLK W/AMP CRIMP CONS WIRE 3.25" WHT W/AMP CRIMP CONS WIRE 13" GRN W/AMP CRIMP CONS WIRE 13" GREY W/AMP CRIMP CONS WIRE 18.5" GREY W/AMP CRIMP CONS WIRE 13" GRN W/AMP CRIMP CONS (REV. B) WIRE 17" RED W/AMP CRIMP CONS WIRE 14" BLK W/AMP CRIMP CONS WIRE 17" BLK W/ AMP CRIMP CONNS WIRE 4" BLUE W/ AMP CRIMP CONNS WIRE 13" WHITE W/AMP CRIMP ON Description IC TIP31A NPN (FF) IC NE5532AN DUAL OPAMP (FF) REG MCT7815CT +15V TO220 (MOT) FOAM PAD TRANSFORMER A4

1 Qty 1 1

MAIN OUTPUT M FAN OUTPUT M
TH 1 TH2 FAN 1 L1, 2 BRIDGE RECTIFIER TRANSFORMER MOUNTING CHASSIS COVER COVER
Top Assembly Final Assembly Module Assembly Module assembly HS 1-4
Final Assembly Module Assembly Final assembly Chassis assembly CONTROL FAN MAIN MAIN OUTPUT M FAN MAIN MAIN FAN MAIN FAN OUTPUT M MAIN OUTPUT MAIN MAIN MAIN MAIN MAIN Packing Assembly S1 S2 Q 1, 2, 7, 20 Q31, 36 Q40, 41, 42, 45 Q 5, 18 Q 10, 23 Q43 Q 6, 11, 19, 24 Q44 Q29, 30, 32, 35, 37, 38 Q 3, 4, 14, 17, 27, 28 Q33, 34 Q 15, 16 Q 9, 22 Q 13, 26 A, D, J BGND-GNDB VR 3,4
OUTPUT OUTPUT MAIN MAIN MAIN MAIN PCB FAN MAIN FAN
SPKR B SPKR A B+ BB, C, E, F, H, K, AGND-GNDA GNDCT Ref.Designator Q 39 U 1-3 U4
4.10 A8 Service Parts List
Group ASY ASY ASY ASY ASY ASY CAB CAB CAB CAB CAB CAB CAB CAB CAB CAB CAB CFC CFC CFC CFC CFC CFC CFC CFC CFC CFC CFC CFC CFC CFC CFC CFC CFD CFD CFD CFD CFD CFD CFM CFR CFR CFR CFR CFR CFR CFR CFR CFR CFR CFR CFR CFR CFR CFR CFR CFR CFR CFR CFR CFR Group Part.Number 7-40-1120 9-79-0115 9-79-0117 9-79-0118 9-79-0119 9-96-1259 4-18-1676 4-18-1677 4-18-1677 4-19-1756 4-19-1757 4-19-1758 4-19-1759 4-19-1760 4-19-1761 4-74-0013 7-41-0006 1-99-0010 1-99-0100 1-99-0101 1-99-0101 1-99-0102 1-99-0102 1-99-0103 1-99-0103 1-99-0104 1-99-0220 1-99-0221 1-99-0221 1-99-0221 1-99-1200 1-99-2200 1-99-3300 2-99-0021 2-99-1757 2-99-4003 2-99-4148 2-99-4148 2-99-5400 2-02-5352 0-99-0010 0-99-0010 0-99-0011 0-99-0012 0-99-0012 0-99-0020 0-99-0027 0-99-0040 0-99-0100 0-99-0102 0-99-0103 0-99-0104 0-99-0104 0-99-0120 0-99-0202 0-99-0223 0-99-0330 0-99-0330 0-99-0511 0-99-0511 0-99-0593 Part.Number Description TRANSFORMER 120V A8 MODULE DISPLAY/VOL A8 MODULE MAIN AMP A8 MODULE OUTPUT A8 ASSY FAN/RELAY/PS A8 ASSY BINDING POSTS COMPLETE A4/A8 CABLE 6" BLK (TWO WIRES TWISTED) CABLE 26" RED/BLK (TWO WIRES TWISTED) CABLE 26" RED/BLK (TWO WIRES TWISTED) CABLE 3-PIN CHNL B I/P A8 CABLE 8-PIN LEVEL CONTROL CABLE 14-PIN TO 4-CON MAIN HARNESS CABLE 3-PIN BIAS CH B CABLE 6-PIN LED CABLE 3-PIN BIAS CH A ASSY WIRE HARNESS 14" (25-PIN D-CON & 26-PIN DIL HDR CON) 26 AWG CABLE POWER W/SPADE LUG (UL/CSA) A4/A8 CAP 10uF ELEC 35V 20% CAP 100PF 100V 5% NPO MC CAP 100uF 25V 20% MUSE CAP 100uF 25V 20% MUSE CAP 0.1uF 100V 5% FILM CAP 0.1uF 100V 5% FILM CAP.01uF 250V 20% XCAP CAP.01uF 250V 20% XCAP CAP 10000uF ELEC 80V 20% CAP 22PF 100V 5% NPO MC CAP 220uF ELEC 25V 20% CAP 220uF ELEC 25V 20% CAP 220uF ELEC 25V 20% CAP 1200PF 100V 5% FILM CAP 2200uF ELEC 25V 20% CAP 3300PF 100V 5% FILM DIODE BAV21 DIODE ZENER 1N757A (9.1V) DIODE POWER 1N4003 DIODE SIGNAL 1N4148 DIODE SIGNAL 1N4148 DIODE POWER 1N5400 DIODE 1N5352BRL 15V 5W 5% RES 10 OHM 1/4W 5% CF RES 10 OHM 1/4W 5% CF RES 10 OHM 3W 5% MO RES 1.2 OHM 1/2W 5% MO RES 1.2 OHM 1/2W 5% MO RES 20 OHM 5W 5% WW RES 2.7 OHM 3W 5% MO RES 40 OHM 5W 5% WIRE WOUND RES 100 OHM 1W 5% MO RES 1K OHM 10W 5% W.W. FORMED RES 10K 1/4W 1% MF RES 10K 1/4W 5% CF RES 10K 1/4W 5% CF RES 120 OHM 5W 5% WW RES 2K OHM 1/4W 5% CF RES 22K 1/4W 5% CF RES 330 OHM 1/4W 5% MO RES 330 OHM 1/4W 5% MO RES 51.1 OHM 1/4W 1% MF RES 51.1 OHM 1/4W 1% MF RES 59K 1/4W 1% MF Description Qty 4 Qty PCB Ref.Designator Comments

FINAL ASSY

B+ RED, B- BLACK J1-J14 (RED) J2 to J18 (gray) J23 TO J20, J13, J8, J3 J12-J19 (YEL,GRN,BLUE) J15 to J17 J16-J21 (BRN,RED,ORANGE)
FAN MAIN MAIN FAN MAIN FAN MAIN FAN MAIN MAIN MAIN OUTPUT M FAN MAIN FAN MAIN MAIN MAIN FAN MAIN FAN FAN MAIN MAIN FAN MAIN MAIN OUTPUT M FAN MAIN FAN MAIN MAIN MAIN MAIN FAN FAN MAIN FAN MAIN OUTPUT M MAIN OUTPUT M MAIN PCB
C45 C17, C39 C2, C3, C16, C35 C49, C50 C9, C11, C14, C18-20, C25, C26, C28, C30, C33, C37, C38, C40 C44, C52 C7 C48 C21-24 C10, C12, C29, C31 C5, C6 C41, C42 C43, C46 C8, C13, C27, C32 C47 C1, C4, C15, C34, C36, C51 CR3, CR5, CR10, CR12 CR4, CR11 CR18, CR26 CR6-9, CR13-16 CR17, CR19, CR20, CR22-25 CR21 CR1, CR2 R35, R42, R75, R103 R142 R64, R66 R27, R29, R56, R58, R61, R68, R71, R74, R99, R101 R105, R107, R109, R112, R115, R120, R123, R125, R127, R129 R132 R65, R67 R130 R9, R11 R25, R50 R3, R6, R16, R19, R40, R53, R84, R95 R12, R13 R134, R139-141, R144, R148-152 R131 R22, R26 R146, R147, R153, R154 R60, R63, R70, R73 R110, R113, R118, R121 R7, R20, R33, R45, R78, R88 R116, R117 R39, R41, R83, R85 Ref.Designator Comments
CFR CFR CFR CFR CFR CFR CFR CFR CFR CFR CFR CFR CFR CFR CFR CFR CFR CFR CON CON CON CON HDR HDR HDR HDR HDR HDR HDR HDR HDR HDR HDR HDW HDW HDW HDW HDW HDW HDW HDW HDW HDW HDW HDW HDW HDW HDW HDW HDW HDW IC JAC LED LED LIT ME ME ME ME ME ME Group ME MIS
0-99-0752 0-99-1000 0-99-1000 0-99-1001 0-99-1001 0-99-1500 0-99-1500 0-99-2210 0-99-3033 0-99-3300 0-99-3300 0-99-3303 0-99-4990 0-99-4991 0-99-4992 0-99-5001 0-99-7682 0-99-9092 4-10-0007 4-10-0007 4-98-0003 4-98-0004 4-15-2002 4-15-2003 4-15-2003 4-15-1002 4-15-1002 4-15-1006 4-15-1006 4-15-1008 4-15-1008 4-15-1014 4-99-0026 5-00-0076 5-00-0077 5-00-0078 5-00-0079 5-00-0085 5-00-0086 5-00-0088 5-00-2006 5-01-0020 5-01-0022 5-02-0005 5-04-0016 5-04-0017 5-04-0018 5-04-0019 5-04-0023 5-05-0001 5-07-0005 2-22-1339 4-05-0007 3-99-0001 3-99-0002 7-51-1107 7-03-0006 7-06-0004 7-06-0010 7-06-0011 7-06-0012 7-10-0029 Part.Number 7-20-0015 5-04-0000
RES 7.5K OHM 1/2W 5% CF RES 1K OHM 1/4W 1% MF RES 1K OHM 1/4W 1% MF RES 1K OHM 1/2W 5% CF RES 1K OHM 1/2W 5% CF RES 1.5K OHM 1/4W 5% CF RES 1.5K OHM 1/4W 5% CF RES 2.21K OHM 1/4W 1% MO RES 0.33 OHM 1/4W 5% METAL OXIDE (FLAMEPROOF) RES 3.3K 1/4W 5% CF RES 3.3K 1/4W 5% CF RES 330K 1/4W 5% CF RES 4.99K 1/4W 1% CF RES 499 OHM 1/4W 1% MF RES 49.9K OHM 1/4W 1% MF RES 5K LINEAR TRIM POT RES 7.68K OHM 1/4W 1% MF RES 9.09K OHM 1/4W 1% MF CON BINDING POST A4, A8 CON BINDING POST A4, A8 STRIP BARRIER (5-POS) DT-55-B-14N-05 TAB FASTON 1/4" (AMP 62650-1) HEADER 2-PIN SIL 0.1 SPC LOCKING (AMP 640456-2) HEADER 3-PIN SIL 2MM CTR (SHROUDED) HEADER 3-PIN SIL 2MM CTR (SHROUDED) HEADER 2-PIN SIL 2mm SPC (shrouded) HEADER 2-PIN SIL 2mm SPC (shrouded) HEADER 6-PIN SIL 2MM CTR (SHROUDED) HEADER 6-PIN SIL 2MM CTR (SHROUDED) HEADER 8-PIN SIL 2MM CTR (SHROUDED) HEADER 8-PIN SIL 2MM CTR (SHROUDED) HEADER 14 PIN SIL 2mm SHROUDED HEADER 26-PIN DIL.100 SPC SCREW 6-32 x 3/8 TAP TIGHT THREAD ROLLING PAN HEAD TROX BLK SCREW 10-32 x 5/16 TAP TIGHT THREAD ROLLING PAN HEAD TROX BLK SCREW 6-32 x 1/2 TAP TIGHT THREAD ROLLING PAN HEAD TROX ZINC SCREW 10-32 x 7/8 TAP TIGHT THREAD ROLLING PAN HEAD TROX ZINC SCREW 8-32 x 1/2 #6 PH TAPTITE TORX BLACK OXIDE W/WAX SCREW M3 x 6MM PPZ MACHINE SCRW,6-32x3/8 PPH THRD LNGR CAD SCREW, JACK, 3/16 X 1/4 WASHER #10 FLAT SPLIT RING RING RETAINING F/P A4/A8 STANDOFF,.400,24AWG,PVC TUBING FASTENER STUD RECEIVER (PUSH-ON) SPACER LED (LTM-480) WASHER #10 FLAT BRASS WASHER.140 ID x.375 OD x.047 VFP INSULATOR TO220 SIL-PAD A4/A8 CLIP STRAIN RELIEF HEYCO 1207 SPACER PCB 5/16 x 1/4 NYLON (RICHCO SSRS-8-4-01) IC LMT339N QUAD COMP (MOT) JACK XLR + 1/4" FEMALE LED RED HIGH EFF (LED TECH LT5241R) LED GREEN (LED TECH LT5221) MANUAL REFERENCE A4/A8 BRIDGE CM3502 35AMP/200V RELAY SPST 901CS-DC12 BREAKER THERMAL CUTOUT 80 DEG.O.O.R. BREAKER THERMAL CUTOUT 55 DEG. C.O.R. CIRCUIT BREAKER 28-XQ1A-20 FAN,DC ST12N6X Description INDUCTOR,AIR CORE 1uH INSULATOR, RECTIFIER 1.250X1.250.200 HOLE

Qty 2 1

MAIN MAIN FAN MAIN FAN MAIN FAN MAIN MAIN MAIN FAN FAN MAIN MAIN MAIN MAIN MAIN MAIN
R54, R96 R32, R44, R47, R52, R77, R87, R90, R94 R145 R10 R143 R51, R93 R138 R31, R43, R76, R86 R23, R24 R55, R97 R135 R133, R136, R137 R1, R2, R4, R5, R14, R15, R17, R18 R8, R21, R48, R49, R91, R92, R155, R156 R36, R80 VR1, VR2 R37, R38, R82 R81
MAIN FAN FAN MAIN OUTPUT M MAIN OUTPUT M DISPLAY MAIN DISPLAY MAIN FAN MAIN

OUTPUT DISP.

J5 P1-25 J22 J1, J12, J14, J16 J19, J21 J3, J9, J10, J13 J 20 J17 J15 J 18 J2, J8 J23 J6 MTG 8 AND COVER TRANSFORMER MOUNTING/AC GND BINDING POST BLOCK BRIDGE RECT. TRANSISTOR CLAMP XLR CONNECTOR Rear panel Rear panel AC ground screw FRONT PANEL FASTENER E AND C LEADS Q35, Q44 DS 1,2,3 BRIDGE RECTIFIER PCB MOUNTING SPACER APPLY TO Q7, Q11, Q28, Q32 MTG1-7, MTG9-11 U4 J4, J11 DS 1, 3 DS 2
MAIN FAN MAIN DISPLAY DISPLAY
FAN MAIN OUTPUT M FAN PCB MAIN

K1, K2 TH1 TH2

Ref.Designator L1, L2 Bridge rectifier

Comments

MIS MIS MIS MIS MTL MTL MTL MTL MTL MTL MTL MTL MTL MTL PLS PLS PLS PLS POT RES RES RUB RUB SWT SWT TRN TRN TRN TRN TRN TRN TRN TRN TRN TRN TRN TRN TRN TRN
5-04-1018 7-70-0007 7-70-0009 7-70-0010 9-03-1146 9-03-1148 9-03-1149 9-03-1151 9-03-1152 9-03-1155 9-03-1156 9-03-1157 9-03-1157 9-03-1164 9-15-0040 9-15-0096 9-15-1189 9-15-1194 0-09-1037 0-99-0033 0-99-0033 9-23-1056 9-23-1057 6-01-0002 6-02-1500 2-03-0006 2-03-0006 2-03-0006 2-03-0056 2-03-0650 2-03-0650 2-03-0750 2-03-0750 2-03-1193 2-03-1194 2-03-1302 2-03-3281 2-04-1837 2-07-4793 2-99-0031 2-99-5532 2-99-7815 9-23-1067
INSULATOR XFMR BRACKET FISH PAPER 5.7 x 14.0 A8 FISH PAPER 1.5 x 13 A8 INSULATOR, FELT DISC.375 DIA. X.032 CHASSIS A8 COVER TOP A8 BRACKET TRANSFORMER A4/A8 CLAMP TRANSISTOR A4/A8 HEATSINK EXTRUSION,150 inch stick (REV C.) HEATSINK A8 HEATSINK THM7022B-MT CLIP HEAT SINK CLP-201 CLIP HEAT SINK CLP-201 HEATSINK RECTIFIER 3 x 1.250 x.125 KNOB 35MM PA INSULATOR K6 A8 PANEL FRONT A4, A8 BLOCK BINDING POST A4,A8 POT 5K SINGLE W/RIGHT ANGLE LEADS RES.33 OHM 3W 5% RES.33 OHM 3W 5% FASTENER FAN (A4 A8) FEET RUBBER.30 x.81 BLK (3M SJ5023) SWITCH SLIDE DPDT SWITCH SPST 16A POWER 1500H11E TRANS MPSA06RLRA TRANS MPSA06RLRA TRANS MPSA06RLRA TRANS MPSA56RLRA TRANS MPS650RLRA TRANS MPS650RLRA TRANS MPS750RLRA TRANS MPS750RLRA TRANS MJL21193 TRANS MJL21194 TRANS MJL1302A TRANS MJL3281A TRANS 2SA1837 TRANS 2SC4793 IC TIP31A NPN (FF) IC NE5532AN DUAL OPAMP (FF) REG MCT7815CT +15V TO220 (MOT) FOAM PAD TRANSFORMER A4

CHASSIS TOP COVER Cover

HEATSINK ASSEMBLY
DISPLAY MAIN OUTPUT M FAN MAIN MAIN OUTPUT M FAN MAIN MAIN FAN MAIN FAN OUTPUT M MAIN OUTPUT MAIN MAIN MAIN FAN MAIN FAN
VR 3,4 R28, R30, R57, R59, R62, R69, R72, R98, R100, R102 R104, R106, R108, R111, R114, R119, R122, R124, R126, R128 INFORMATION PACK S1 S2 Q1, Q2, Q4, Q25 Q35, Q44 Q47, Q48, Q50, Q52 Q3, Q24 Q8, Q29 Q51 Q5, Q9, Q26, Q30 Q49 Q33, Q34, Q36-38, Q41-43, Q45, Q46 Q12-16, 19-23 Q39, Q40 Q17, Q18 Q7, Q28 Q11, Q32 Q306 U1-3 U5