CROWN K-SVCMT12 8-95 Micro Tech 1200 Amplifier User Manual

POWER AMPLIFIER
SERVICE MANUAL
MACRO-TECH® -1200

K-SVCMT12 8-95 Micro Tech 1200 Amplifier

The information furnished in this manual does not include all of the details of design, production, or variations of the equipment. Nor does it cover every possible situation which may arise during installation, operation or maintenance. If you need special assistance beyond the scope of this manual, please contact the Crown Technical Support Group.
Mail: P.O. Box 1000 Elkhart IN 46515-1000
Shipping: 57620 C.R. 105 Elkhart IN 46517
Phone: 800-342-6939/219-294-8200
FAX: 219-294-8301

CAUTION
TO PREVENT ELECTRIC SHOCK DO NOT REMOVE TOP OR BOTTOM COVERS. NO USER SERVICEABLE PARTS INSIDE. REFER SERVICING TO QUALIFIED SERVICE PERSONNEL. DISCONNECT POWER CORD BEFORE REMOVING REAR INPUT MODULE TO ACCESS GAIN SWITCH.
WARNING
TO REDUCE THE RISK OF ELECTRIC SHOCK, DO NOT EXPOSE THIS EQUIPMENT TO RAIN OR MOISTURE!

Introduction

This manual contains service information on Crown
power amplifiers. It is designed to be used in conjunction with the applicable Owner’s Manual.
However, some important information is duplicated in this Service Manual in case the Owner’s Manual is not readily available.
NOTE: THE INFORMATION IN THIS MANUAL IS INTENDED FOR USE BY AN EXPERIENCED TECHNICIAN ONLY!
Scope
This Service Manual in intended to apply to all versions of the MA-1200 amplifier including the Amcron MA1201. The Parts Listings include parts specific for the US version and the European version (MA-1200E13).
For parts specific only to other versions contact the Crown Technical Support Group for help in finding  partnumbers.
This Service Manual includes several sections. These sections include Parts Information, Specifications, Voltage Conversion, Circuit Theory, Electrical Test Procedures, Non-Module Parts Lists, and Module Parts Lists. Schematics are attached.
Note that component parts with circuit board comprise a complete module. Module part numbers are always associated with a specific circuit board, although an unpopulated circuit board may be built up with different parts to create different modules. Note that Crown does not sell blank (unpopulated) circuit boards.
Each of the compact audio power amplifiers are designed for professional or commercial use. Providing high power amplification from 20Hz to 20KHz with minimum distortion, they feature balanced inputs with bridged and parallel monophonic capability.
Specific features vary depending on model family.
Warranty
Each Owner’s Manual contains basic policies as related to the customer. In addition it should be stated that this service documentation is meant to be used only by properly trained service personnel. Because most Crown products carry a 3 Year Full Warranty (including round trip shipping within the United States), all warranty service should be referred to the Crown Factory or Authorized Warranty Service Center. See the applicable Owner’s Manual for warranty details. To find the location of the nearest Authorized
Service Center or obtain instructions for receiving Crown Factory Service please contact the Crown Technical Support Group (within North America) or your Crown/ Amcron Importer (outside North America).

Crown
Technical Support Group
Factory Service
Parts Department
Mailing Address:
PO Box 1000
Elkhart, IN USA 46515-1000
Shipping Address:
57620 C.R. 105
Elkhart, IN USA 46517
Phone: 219-294-8200
Toll Free: 800-342-6939
FAX: 219-294-8301

Parts Information

General Information
Later sections include both mechanical and electrical parts lists for this product. The parts listed are current as of the date printed. Crown reserves the right to modify and improve its products for the benefit of its customers.
Part Numbering Systems
As of the printing of this manual, Crown is using two numbering systems. The elder system always uses eight characters. The first character is a letter. Common letters used are C, D, H, M, P, and Q. The second through sixth characters are numbers. The numbers build sequentially (for each prefix letter) as new parts are added to our parts inventory system. (In some cases there will be a space then a four character number after the prefix letter; the space is considered a character.) The seventh character is usually a hyphen, though it may be a letter to indicate a revision or special note. The last character is called a check-digit, and is useful to Crown for internal tracking.
Crown is in the process of converting to a new part number system. Length may vary from eight to twelve characters. There is still a letter prefix, then five numbers. These five numbers identify a type of part. The seventh character is a hyphen. Remaining characters identify the details of the type of part identified by the first part of the number.
Standard and Special Parts
Many smaller electrical and electronic parts used by Crown are stocked by and available from electronic supply houses. However, some electronic parts that appear to be standard are actually special. A part ordered from Crown will assure an acceptable replacement. Structural items such as modules and panels are available from Crown only.
Ordering Parts
When ordering parts, be sure to give the product model, and include a description and part number (CPN/DPN) from the parts listing. Price quotes are available on request.
Shipment
Shipment will be normally made by UPS or best other method unless you specify otherwise. Shipments are made to and from Elkhart, Indiana USA, only. Established accounts with Crown will receive shipment freight prepaid and will be billed. All others will receive shipment on a C.O.D. or pre-payment (check or credit card) basis.

Terms
Normal terms are pre-paid. Net-30 Days applies to only those firms having pre- established accounts with Crown. If pre-paying, the order must be packed and weighed before a total bill can be established, after which an amount due will be issued and shipment made upon receipt of pre-payment. New parts returned for credit are subject to a 10% re-stocking fee, and authorization from the Crown Parts Department must be obtained before returning parts for credit.
Crown is not a general parts warehouse. Parts sold by the Crown Parts Department are solely for servicing Crown/Amcron products. Part prices and availability are subject to change without notice.

Crown
Parts Department
Mailing Address:
PO Box 1000
Elkhart, IN USA 46515-1000
Shipping Address:
57620 C.R. 105
Elkhart, IN USA 46517
Phone: 219-294-8210
or: 219-294-8211
Toll Free: 800-342-6939
FAX: 219-294-8301

Specifications

Unless noted otherwise, all specifications are based on driving an 8 ohm load per channel, both channels driven, the sensitivity switch in the 26dB position, the AC supply is 120VAC at 60Hz. Crown specifications are guaranteed through the warranty period (normally 3 years). Because our testing methods are more stringent than our published specifications, every Crown amplifier will exceed its published specifications.
POWER
Power
8 Ohm Stereo—310W/Ch
4 Ohm Stereo—480W/Ch
2 Ohm Stereo—675W/Ch
8 Ohm Bridge Mono—970W
4 Ohm Bridge Mono—1300W
2 Ohm Parallel Mono—965W
1 Ohm Parallel Mono—1300W

Load Impedances: Rated for 16, 8, 4, 2, and 1 (parallel mono only) Ohm operation; safe with all types of loads, even totally reactive loads.
AC Mains: 120VAC at 60 Hz with standard three-wire grounded connector for North American units; 100VAC, 120VAC, 220VAC, and 240VAC at 50 or 60 Hz when equipped with universal transformers, applicable fan assembly, and other applicable hardware with country specific power cord.
PERFORMANCE
Frequency Response: ±0.1dB from 20 Hz to 20 kHz at 1 Watt.
Phase Response: ±10° from 10 Hz to 20 kHz at 1 Watt.
Signal to Noise Ratio: A-weighted, better than 105 dB below full rated output. Better than 100 dB below full rated output from 20 Hz to 20 kHz.
Total Harmonic Distortion (THD): <0.05% from 20 Hz to 1 kHz, increasing linearly to 0.1% at 20 kHz at 500W.
I.M. Distortion: <0.05% from less than 164 milliwatts to 520 W at 26 dB gain.
Slew Rate: >13V per microsecond. (Slew rates are limited to useful levels for ultrasonic/RF protection.)
Damping Factor: >1000 from 10 Hz to 400 Hz.
DC Offset: <10 millivolts.
Input Impedance: Nominally 20K ohms balanced; 10K ohms unbalanced.
Output Impedance: <10 milliohms in series with <2 microhenries.
Protection Systems: Output Device Emulation Protection (ODEP) limits drive in the event of dangerous dynamic thermal conditions without interrupting  power. Current limiting for shorted load protection. DC/LFand common mode output current Fault circuitry to mute audio. Delay of 4 seconds from turn on mutes amplifier to prevent dangerous turn-on transients. A high voltage fuse in each main transformer primary and a low voltage power supply fuse in fan primary. Slew rate limiting to prevent RF burn out.
MECHANICAL
Input Connectors: Balanced 1/4 inch phone jacks. Balanced female XLR connector for each channel on the standard P.I.P.-FX module.
Output Connectors: Color-coded 5-way binding posts on 3/4 inch centers; spaced 3/4 inch apart.
Front Panel Controls: A front panel push button switch used to power the amplifier on and off. A detented front panel rotary potentiometer for each channel used to control the output level. Back Panel Controls: A three- position switch which selects Stereo, Bridge-Mono, or Parallel-Mono mode. A ground lift switch used to isolate the phone jack input grounds from the chassis (AC) ground. Internal Controls: A three-position switch located inside the P.I.P compartment selects 0.775V, 1.4V, or 26 dB voltage gain input sensitivity. Indicators: Amber Enable indicator shows on/off status of low- voltage power supply. An Amber ODEP indica- tor for each channel shows the reserve energy status. If no reserve energy is available the indicator will dim in proportion to ODEP limiting. A green SIGNAL/IOC two function indicator for each channel flashes to show that there is amplifier output. The indicator flashes with brighter intensity if the amplifier causes any distortion of 0.05% or more. Construction: Black splatter-coat steel chassis with specially designed flow-through ventilation system. Mounting: Standard EIA 310 front- panel rack mount with supports for supplemental rear corner mounting. Dimensions: 19 inches wide, 3.5 inches high, 16 inches deep behind front mounting surface. Weight: 44 lbs, 1 oz (20.0 kg). Shipping; 47 lbs (21.3 kg).

Voltage Conversion

The 120 Volt 60 Hz version, sold in the United States, is not voltage selectable. It does not have voltage selection boards. This version is to be used only with 120 Volts, 60Hz.
All other versions of the Macro Tech 1200 use voltage selection boards. The following chart indicates which jumpers are used for different voltages. Note that the fuses and transmotor may need to be changed to accommodate different voltages. Versions with the
voltage selection boards may be used at 50 or 60 Hz.

VOLTAGE SELECTION BOARD

| 100V| 120V| 200V| 220V/230V| 240V
---|---|---|---|---|---
Jumpers| Z101
Z104
Z106
Z201
Z204
Z206| Z100
Z104
Z105
Z200
Z204
Z205| Z101
Z103
Z201
Z203| Z101
Z102
Z201
Z202| Z100
Z102
Z200
Z202
Fuses| |
F100/F200| A10285 28,20us,| A10285-26,10A
Transmotor TF1| H43068.8| H43407.8| H43061.3

Theory

Overview
It should be noted that over time Crown makes improvements and changes to their products for various reasons. This manual is up to date as of the time of writing. For additional information regarding these amplifiers, refer to the applicable Technical Notes provided by Crown for this product. This section of the manual explains the general operation of a typical Crown power amplifier. Topics covered include Front End, Grounded Bridge, and ODEP. Due to variations in design from vintage to vintage (and similarities with other Crown products) the theory of operation remains simplified.
Features
Macro Tech amplifiers utilize numerous Crown innovations including grounded bridge and ODEP technologies. Cooling techniques make use of the what is essentially air conditioner technology. Air flows bottom to top, and front to side. Air flows a short distance across a wide heatsink. This type of air flow provides significantly better cooling than the “wind tunnel” technology used by many other manufacturers. Output transistors are of the metal can type rather than plastic case. This allows for a significantly higher thermal margin for the given voltage and current ratings. All devices used are tested and graded to ensure maximum reliability. Another electronic technique used is negative feedback. Almost all power amplifiers utilize negative feedback to control gain and provide stability, but Crown uses multiple nested feedback loops for maximum stability and greatly improved damping. Most Crown amplifiers have damping in excess of 1000 in the bass frequency range. This feedback, along with our compensation and ultra-low distortion output topology, make Crown amplifiers superior. Features specific to the Macro Tech Series’ include two seperate power transformers (one for each channel), a full time full speed fan which also serves as the low voltage transformer, slew rate limiting, and audio muting for delay or protective action. This amplifier can operate in either a Bridged or Parallel Mono mode as well as dual (stereo). A sensitivity switch allows selection of input voltage required for rated output. Level controls are mounted on the front panel and are of the rotary type. Front panel indicators let the user know the status of the low voltage power supply (enable), an ODEP indicator for each channel which shows the reserve energy status, and a SPI/IOC indicator for each channel which indicates signal output and distortion. In general, the packaging of this model is designed for maximum watt/price/weight/ size value with user friendly features.
For additional details refer to the specification section, or to the applicable Owner’s Manual.
Front End Operation
The front end is comprised of three stages: Balanced Gain Stage (BGS), Variable Gain Stage (VGS), and the Error Amp. Figure 1 shows a simplified diagram of a typical front end with voltage amplification stages. Balanced Gain Stage (BGS) Input to the amplifier is balanced. The shield may be isolated from chassis ground by an RC network to interrupt ground loops via the Ground Lift Switch. The non-inverting (hot) side of the balanced input is fed to the non-inverting input of the first op-amp stage. The inverting (negative) side of the balanced input is fed to the inverting input of the first op-amp stage. A potentiometer is provided for common mode rejection adjustment. Electrically, the BGS is at unity gain. (From an audio perspective, however, this stage actually provides +6dB gain if a fully balanced signal is placed on its input.) The BGS is a non-inverting stage. It’s output is delivered to the Variable Gain Stage. Variable Gain Stage (VGS) From the output of the BGS, the signal goes to the VGS where gain is determined by the position of the Sensitivity Switch, and level is determined by the level control. VGS is an inverting stage with the input being fed to its op-amp stage. Because gain after this stage is fixed at 26dB (factor of 20), greater amplifier sensitivity is achieved by controlling the ratio of feedback to input resistance. The Sensitivity Switch sets the input impedance to this stage and varies the gain such that the overall amplifier gain is 26 dB, or is adjusted appropriately for 0.775V or 1.4V input to attain rated output.
Error Amp
The inverted output from the VGS is fed to the noninverting input of the Error Amp op-amp stage through an AC coupling capacitor and input resistor. Amplifier output is fed back via the negative feedback (NFb) loop resistor. The ratio of feedback resistor to input resistor fixes gain from the Error Amp input to the output of the amplifier at 26 dB. Diodes prevent overdriving the Error Amp. Because the Error Amp amplifies the difference between input and output signals, any difference in the two waveforms will produce a near open loop gain condition which in turn results in high peak output voltage. The output of the Error Amp, called the Error Signal (ES) drives the Voltage Translators.
Voltage Amplification
The Voltage Translator stage separates the output of the Error Amp into balanced positive and negative drive voltages for the Last Voltage Amplifiers (LVAs), translating the signal from ground referenced ±15V to ±Vcc reference. LVAs provide the main voltage amplification and drive the High Side output stages. Gain from Voltage Translator input to amplifier output is a factor of 25.2.
Voltage Translators
A voltage divider network splits the Error Signal (ES) into positive and negative drive signals for the balanced voltage translator stage. These offset reference voltages drive the input to the Voltage Translator transistors. A nested NFb loop from the output of the
amplifier mixes with the inverted signal riding on the offset references. This negative feedback fixes gain at the offset reference points (and the output of the Error Amp) at a factor of -25.2 with respect to the amplifier output. The Voltage Translators are arranged  in a common base configuration for non- inverting voltage gain with equal gain. They shift the audio from the ±15V reference to VCC reference. Their outputs drive their respective LVA.
Also tied into the Voltage Translator inputs are ODEP limiting transistors and control/protection transistors. The ODEP transistors steal drive as dictated by the ODEP circuitry (discussed later). The control/protection transistors act as switches to totally shunt audio to ground during the turn-on delay, or during a DC/LF or Fault protective action. Last Voltage Amplifiers (LVAs) The Voltage Translator stage channels the signal to the Last Voltage Amplifiers (LVA’s) in a balanced configuration. The +LVA and -LVA, with their push-pull effect through the Bias Servo, drive the fully complementary output stage. The LVAs are configured as common emitter amplifiers. This configuration provides sufficient voltage gain and inverts the audio. The polarity inversion is necessary to avoid an overall polarity inversion from input jack to output jack, and it allows the NFb loop to control Error Amp gain by feeding back to its non-inverting input (with its polarity opposite to the output of the VGS). With the added voltage swing provided by the LVAs, the signal then gains current amplification through the Darlington emitter-follower output stage. Grounded Bridge Topology Figure 2 is a simplified example of the grounded bridge output topology. It consists of four quadrants of three deep Darlington (composite) emitter-follower stages per channel: one NPN and one PNP on the High Side of the bridge (driving the load), and one NPN and one PNP on the Low Side of the bridge (controlling the ground reference for the rails). The output stages are biased to operate class AB+B for ultra low distortion in the signal zero-crossing region and high efficiency.

High Side (HS) The High Side (HS) of the bridge operates much like a conventional bipolar push-pull output configuration. As the input drive voltage becomes more positive, the HS NPN conducts and delivers positive voltage to the load. Eventually the NPN devices reach full conduction and +Vcc is across the load. At this time the HS PNP is biased off. When the drive signal is negative going, the HS PNP conducts to deliver -Vcc to the load and the HS NPN stage is off. The output of the +LVA drives the base of predriver device. Together, the predriver and driver form the first two parts of the three-deep Darlington and are biased class AB. They provide output drive through the bias resistor, bypassing the output devices, at levels below about 100mW. An RLC network between the predriver and driver provide phase shift compensation and limit driver base current to safe levels. Output devices are biased class B, just below cutoff. At about 100mW output they switch on to conduct high current to the load. Together with predriver and driver, the output device provide an overall class AB+B output. The negative half of the HS is almost identical to the positive half, except that the devices are PNP. One difference is that the PNP bias resistor is slightly greater in value so that PNP output devices run closer to the cutoff level under static (no signal) conditions. This is because PNP devices require greater drive current. HS bias is regulated by Q18, the Bias Servo. Q18 is a Vbe multiplier which maintains approximately 3.3V Vce under static conditions. The positive and negative halves of the HS output are in parallel with this 3.3V. With a full base-emitter on voltage drop across predrivers and drivers, the balance of voltage results in approximately .35V drop across the bias resistors in the positive half, and about .5V across the bias resistor in the negative half. Q18 conduction (and thus bias) is adjustable. A diode string prevents excessive charge build up within the high conduction output devices when off. Flyback diodes shunt back-EMF pulses from reactive loads to the power supply to protect output devices from dangerous reverse voltage levels. An output terminating circuit blocks RF on output lines from entering the amplifier through its output connectors. Low Side (LS) The Low Side (LS) operates quite differently. The power supply bridge rectifier is not ground referenced, nor is the secondary of the main transformer. In other words, the high voltage power supply floats

with respect to ground, but ±Vcc remain constant with respect to each other. This allows the power supply to deliver +Vcc and -Vcc from the same bridge rectifier and filter as a total difference in potential, regardless of their voltages with respect to ground. The LS uses inverted feedback from the HS output to control the ground reference for the rails (±Vcc). Both LS quadrants are arranged in a three-deep Darlington and are biased AB+B in the same manner as the HS. When the amplifier output swings positive, the audio is fed to an op-amp stage where it is inverted. This inverted signal is delivered directly to the bases of the positive (NPN) and negative (PNP) LS predrivers. The negative drive forces the LS PNP devices on (NPN off). As the PNP devices conduct, Vce of the PNP Darlington drops. With LS device emitters tied to ground, -Vcc is pulled toward ground reference. Since the power supply is not ground referenced (and the total voltage from +Vcc to -Vcc is constant) +Vcc is forced higher above ground potential. This continues until, at the positive amplifier output peak, -Vcc = 0V and +Vcc equals the total power supply potential with a positive polarity. If, for example, the power supply produced a total of 70V from rail to rail (±35VDC measured from ground with no signal), the amplifier output would reach a positive peak of +70V. Conversely, during a negative swing of the HS output where HS PNP devices conduct, the op-amp would output a positive voltage forcing LS NPN devices to conduct. This would result in +Vcc swinging toward ground potential and -Vcc further from ground potential. At the negative amplifier output peak, +Vcc = 0V and -Vcc equals the total power supply potential with a negative polarity. Using the same example as above, a 70V supply would allow a negative output peak of 70V. In summary, a power supply which produces a total of 70VDC rail to rail (or ±35VDC statically) is capable of producing 140V peak-to-peak at the amplifier output when the grounded bridge topology is used. The voltage used in this example are relatively close to the voltages of the PB-1/460CSL. The total effect is to deliver a peak to peak voltage to the speaker load which is twice the voltage produced by the power supply. Benefits include full utilization of the power supply (it conducts current during both halves of the output signal; conventional designs require two power supplies per channel, one positive and one negative), and never exposing any output device to more than half of the peak to peak output voltage (which does occur in conventional designs).
Low side bias is established by a diode string which also shunts built up charges on the output devices. Bias is adjustable via potentiometer. Flyback diodes perform the same function as the HS flybacks. The output of the LS is tied directly to chassis ground via
ground strap.
Output Device Emulation Protection (ODEP) To further protect the output stages, a specially developed ODEP circuit is used. It produces a complex analog output signal. This signal is proportional to the always changing safe- operating-area margin of the output transistors. The ODEP signal controls the Voltage Translator stage by removing drive that may exceed the safe-operating- area of the output stage. ODEP senses output current by measuring the voltage dropped across LS emitter resistors. LS NPN current (negative amplifier output) and +Vcc are sensed, then multiplied to obtain a signal proportional to output power. Positive and negative ODEP voltages are adjustable via two potentiometers. Across ±ODEP are a PTC and a thermal sense (current source). The PTC is essentially a cutoff switch that causes hard ODEP limiting if heatsink temperature exceeds a safe maximum, regardless of signal level. The thermal sense causes the differential between +ODEP and – ODEP to decrease as heatsink temperature increases. An increase in positive output signal output into a load will result in –ODEP voltage dropping; an increase in negative output voltage and current will cause +ODEP voltage to drop. A complex RC network between the ±ODEP circuitry is used to simulate the thermal barriers between the interior of the output device die (immeasurable by normal means) and the time delay from heat generation at the die until heat dissipates to the thermal sensor. The combined effects of thermal history and instantaneous dynamic power level result in an accurate simulation of the actual thermal condition of the output transistors.

Electrical Checkout Procedures

General Information
The following test procedures are to be used to verify operation of this amplifier. DO NOT connect a load or inject a signal unless directed to do so by the procedure. These tests, though meant for verification and alignment of the amplifier, may also be very helpful in troubleshooting. For best results, tests should be performed in order.
All tests assume that AC power is from a regulated 120 VAC source. Test equipment includes an oscilloscope, a DMM, a signal generator, loads, and I.M.D. and T.H.D. noise test equipment.
Standard Initial Conditions Level controls fully clockwise. Stereo/Mono switch in Stereo. Sensitivity switch in 26 dB fixed gain position. It is assumed, in each step, that conditions of the amplifier are per these initial conditions unless otherwise specified.
Test 1: DC Offset
Spec: 0 VDC, ±10 mV.
Initial Conditions: Controls per standard, inputs shorted. Procedure: Measure DC voltage at the output connectors (rear panel). There is no adjustment for output offset. If spec is not met, there is an electrical malfunction. Slightly out of spec measurement is usually due to U104/U204 out of tolorance.
Test 2: Output Bias Adjustment
Spec: 300 to 320 mVDC. Initial Conditions: Controls per standard, heatsink temperature less than 40°C. Procedure: Measure DC voltages on the output module across R02, adjust R26 if necessary. Measure DC voltages on the output module across R21, adjust R23 if necessary. Repeat for second channel.
Test 3: ODEP Voltage Adjustment
Spec: Bias Per Chart, ±0.1V DC. Initial Conditions: Controls per standard, heatsink at room temperature 20 to 30°C (68 to 86°F). Note: This adjustment should normally be performed within 2 minutes of turn on from ambient (cold) conditions. If possible measure heatsink temperature, if not measure ambient room temperature. Use this information when referencing the following chart.
The following is a list of ODEP bias voltages VS. temperature.

–ODEP Procedure: Measure pin 6 of U100 and, if necessary, adjust R121 to obtain V–ODEP as specified above. Measure pin 6 of U200 and, if necessary, adjust R221 to obtain V–ODEP as specified above. +ODEP Procedure: Measure pin 6 of U103 and, if necessary, adjust R132 to obtain V+ODEP as specified above. Measure pin 6 of U203 and, if necessary, adjust R232 to obtain V as specified above.
Test 4: AC Power Draw
Spec: 100 Watts maximum quiescent.
Initial Conditions: Controls per standard.
Procedure: With no input signal and no load, measure AC line wattage draw. If current draw is excessive, check for high AC line voltage or high bias voltage.
Test 5: Common Mode Rejection
Spec at 100 Hz: –70 dB.
Spec at 20 kHz: –50 dB.
Initial Conditions: Controls per standard.
Procedure: No load. Inject a 0 dBu (.775VRMS) 100 Hz sine wave into each channel, one channel at a time, with inverting and non-inverting inputs shorted together. At the output measure less than –44 dBu (4.9mVRMS). Inject a 0 dBu 20 kHz sine wave into each channel, one channel at a time, with inverting and non-inverting inputs shorted together. At the output measure less than –24 dBu (49mVRMS). For Main Modules with board numbers lower than D 7993-5 adjust N100 and N200 to calibrate CMR. For Main Modules with board number D 7993-5 or greater adjust R921 and R1021.
Test 6: Voltage Gain
Spec 26dB Gain: Gain of 20.0 ±3%.
Spec 0.775V Sensitivity: ±6%.
Spec 1.4V Sensitivity: +12%/–6%.
Initial Conditions: Controls per standard.
Procedure: No load connected. Inject a 0.775 VAC 1 kHz sine wave with the Sensitivity Switch in the 26 dB position. Measure 15.5 VAC ±0.5 VAC at the amplifier output. Inject a 0.775 VAC 1 kHz sine wave with the Sensitivity Switch in the 0.775V position. Measure 50.6 VAC ±3 VAC at the amplifier output. Inject a 1.4 VAC 1 kHz sine wave with the Sensitivity Switch in the 1.4V position. Measure 50.6 VAC +6/–3 VAC at the amplifier output. Return the Sensitivity Switch to the 26 dB position.
Test 7: Phase Response
Spec: ±10° from 10 Hz to 20 kHz at 1 Watt. Initial Conditions: Controls per standard, 8 ohm load on each channel. Procedure: Inject a 1 kHz sine wave and adjust for 1 Watt output (2.8 VAC). Check input and output signals against each other, input and output signals must be within 10° of each other.
Test 8: Level Controls
Spec: Level controlled by level controls. Initial Conditions: Controls per standard. Procedure: No Load. Inject a 1 kHz sine wave. With level controls fully clockwise you should see full gain. As controls are rotated counterclockwise, observe similar gain reduction in each channel. When complete, return level controls to fully clockwise position.
Test 9: Current Limit
Spec: Current Limit at 30 Amps, ±2 Amps Initial Conditions: Controls per standard. Procedure: Load each channel to 1 Ohm. Inject a 1 kHz differentiated (or 10% duty cycle) square wave. See figure 4. Increase output level until current limit occurs. Current limit should occur at 30 ±2 Amps (30 Vpk). Observe clean (no oscillations) current clipping.

Test 10: Slew Rate & 10 kHz Square Wave Spec: 13 – 15 V/µS.
Initial Conditions: Controls per standard. Procedure: Load each channel to 8 ohms. Inject a 10 kHz square wave to obtain 65 volts zero-to-peak at each output. Observe the slope of the square wave. It should typically measure 13 to 15 V/µS. Also, the square wave must not include overshoot, ringing, or any type of oscillation.
Test 11: Crosstalk
Spec: -60dB at 20 kHz. Initial Conditions: Controls per standard. Terminate input of channel not driven with 600 ohms. Procedure: 8 ohm load on each channel. Inject a 20 kHz sine wave into the Channel 1 input and increase output level to 33 VAC. Measure less than 33 mVAC at the output of Channel 2. Inject a 20 kHz sine wave into the Channel 2 input and increase output level to 33 VAC. Measure less than 33 mVAC at the output of Channel 1.
Test 12: Output Power
Spec at 8 Ohm Stereo: >= 320W at 0.1% THD.
Spec at 4 Ohm Stereo: >= 470W at 0.1% THD.
Spec at 2 Ohm Stereo: >= 600W at 0.1% THD.
International 8 Ohm Stereo: >=305W at 0.1% THD.
International 4 Ohm Stereo: >=430W at 0.1% THD.
International 2 Ohm Stereo: >=535W at 0.1% THD.
Initial Conditions: Controls per standard.
Procedure: Load each channel to 8 ohms. Inject a 1 kHz sine wave and measure at least 50.6 VAC at the output of each channel. Load each channel to 4 ohms. Inject a 1 kHz sine wave and measure at least 43.36 VAC.
Load each channel to 2 ohms. Inject a 1 kHz sine wave  and measure at least 34.64 VAC. All power measurements must be at less than 0.1% THD.
Test 13: Reactive Loads
Spec: No oscillations. Safe with all types of loads.
Initial Conditions: Controls per standard.
Procedure Capacitive: Load each channel to 8 ohms in parallel with 2 µF. Inject a 20 kHz sine wave with 33 VAC output for 10 seconds.
Procedure Inductive: Load each channel to 8 ohms in parallel with 159 µHenries. Inject a 1 kHz sine wave with 20 VAC output for 10 seconds.
Procedure Torture: Load each channel with the primary (red and black leads) of a DC-300A transformer (D 5781-6). Inject a 15 Hz sine wave at sufficient output level to cause 3 to 5 flyback pulses, for 10 seconds.
Procedure Short: Inject a 60 Hz sine wave at 20 VAC output. After establishing signal, short the output for 10 seconds.
Test 14: ODEP Limiting
Spec: No oscillation on ODEP Limiting wave form; either channel controls limiting in Parallel Mono Mode. Initial Conditions: Controls per standard; rag or other obstruction blocking fan so that it does not turn. Procedure: Load the amplifier to 2 ohms on each
channel. Inject a 60 Hz sine wave and adjust for 20 Vrms at the output. After a few minutes observe a wave form similar to Figure 5. Remove the input signal from both channels and allow the amplifier to cool for a few minutes. Switch the amplifier to Parallel Mono and remove the load from Channel 1. Inject the signal into Channel 1 and observe that ODEP limiting occurs at the output of both channels. Remove the load from Channel 2, and install the load on Channel

1. Again, observe that both channels limit. Return all amplifier controls to standard initial conditions. Remove the fan obstruction.

Test 15: LF Protection
Spec: Amplifier mutes for low frequency. Initial Conditions: Controls per standard. Procedure: No load. Inject a 0.5 Hz 6 volt peak-to-peak square wave, or a 2 Hz 6VAC sine wave into each channel and verify that each channel cycles into mute.
Test 16: Signal to Noise Ratio
Spec: 100 dB below rated 8 ohm power 20 Hz to 20 kHz. 105 dB A-Weighted. Initial Conditions: Controls per standard. Short inputs. Procedure: Load each channel to 8 ohms. Measure less than 506 µV at the output of each channel (20 Hz20 kHz bandpass filter).
Test 17: Turn On Transients
Spec: No dangerous transients. Initial Conditions: Controls per standard. Procedure: From an off condition, turn on the amplifier and monitor the output noise at the time of turn on.
Note: Turn on noise may increase significantly if the amplifier is cycled off and on.
Test 18: Turn Off Transients Spec: No dangerous transients.
Initial Conditions: Controls per standard.
Procedure: From an on condition, turn off the amplifier and monitor the output noise at the time of turn off.
Note: Turn off noise may increase significantly if the amplifier is cycled off and on.
Test 19: Intermodulation Distortion
Spec at 0 dB Output: 0.01%.
Spec at –35 dB Output: 0.05%.
Initial Conditions: Controls per standard.
Procedure: Load each channel to 8 ohms. Inject a SMPTE standard IM signal (60 Hz and 7 kHz sine wave mixed at 4:1 ratio). Set the 60 Hz portion of the sine wave to 38.9 Volt RMS. Set the 7 kHz portion to 25%. With an IM analyzer measure less than 0.01% IMD. Repeat test at –35 dB (reference 38.9 Volt RMS, 60 Hz portion) and measure less than 0.05% IMD.
Test 20: Clipping
Spec: No protective action during test. Initial Conditions: Controls per standard. Procedure: Load each channel to 8 ohms. Inject a 1 kHz sine wave at each input and drive output 6 dB into clip for 10 seconds. The amplifier should not activate any protective circuits (ODEP, Fault, or LF Protection).
Post Testing
After completion of testing, if all tests are satisfactory, the amplifier controls should be returned to the positions required by customer. If conditions are unknown or unspecified, factory settings are as follows:
Level Controls: 9 to 11 O’Clock.
Sensitivity Switch: 0.775V U.S., 1.4V International.
Stereo/Mono Switch: Stereo.
Ground Lift: Lift.
Power: Off.
Parts List (Non-Module)

SUPPLIMENTAL ITEMS

POWER SUPPLY

OUTPUT ASSEMBLY (ONE PER CHANNEL)

-For units with output board P10305-4 use Sil Pad D 6280-8.
-For use with output boards earlier than P10305-4 use
Sil Pad D 6104-0.| 1
D 7797-0| Output Pad (between module and chassis)
-For units with output board P10305-4 use Output Pad C 7597-4.
-For units with ouput boards earlier than P10305-4 use
Output Pad D 7026-4.| 1
D 8197-2| Paper Shroud| 1
C 9387-9| Plasti-Rivit| 2

OUTPUT ASSEMBLY (CONT.)

BACK PANEL ASSEMBLY

CHASSIS FRONT ASSEMBLY

To upgrade the old plastic filter assembly to the new metal style, a kit may be ordered using Crown part number M44077-2. This kit includes a new bottom cover.
MAIN CHASSIS ASSEMBLY

-Note: The old Style bottom cover used with the plastic grill is no longer available. You may
upgrade to the new style by ordering the kit M44077-2.| 1

MAIN CHASSIS ASSEMBLY (CONT.)

Module and Schematic Information

MODULE HISTORY
The Micro Tech 1200 amplifier was introduced in January 1986. Since then there have been several updates and revisions, some of which called for new modules. The following is a list of all modules used up to this date, August 1995.
OUTPUT MODULES: (left and right are identical)
Q42549-8
Original output module on P10115-7 board. No longer available. Use Q42717-1 as service replacement.
Q42647-0
Output module on P10137-1. No longer available. Use Q42717-1 as service replacement.
Q42717-1
Output module on P10233-8 board.
Q42871-6
Output module on P10305-4 board.
Q42968-0
Output module on P10341-9 board. No longer available. Use Q43202-3 as service replacement.
Q43202-3
Output module on P10397-1 board.
MAIN MODULES:
Q42552A0
Original main module on D 6304A4 or D 6304B2
board. No longer available. Use Q42776-7 as service
replacement.
Q42714-8
Main module on D 6910-0 board. No longer available.
Use Q42776-7 as service replacement.
Q42776-7
Main module on D 7251-8 board. Used as a replacement for all older modules.
Q42980-5
Main module on D 7911-7 board. No longer available
use Q43033-2 as service replacement.
Q43035-7
Main module on D 7993-5 board. No longer available use Q43033-2 as service replacement.
Q43031-6
Main module on D 7993-5 board.
FUSE MODULE:
M43534-3 (120V 60Hz U.S. Units Only)
Fuse module on P10391-4 board.
Q42866-6 -Channel 2 (Universal Volt Units Only)
Fuse module on P10296-5 board.
Q42867-4 -Channel 1 (Universal Volt Units Only)
Fuse module on P10295-7 board.
DISPLAY MODULE:
Q43061-3 (With ODEP Indicators) Display module on D 8030-5 board.
M43530-1 (Old style with SUPPLY Indicators) LED Assembly.
SCHEMATIC INFORMATION:
The schematics provided are representative only. There may be slight variations between amplifier to amplifier. These schematics are intended to be used for troubleshooting purposes only.
For amplifiers with main boards D 6304A4, D 6304B2 or D 6910-0 refer to schematic number J0190-9.
For amplifiers with main board D 7251-8 refer to schematic number J0444-0.
For amplifiers with main boards D 7911-7 or D 79935 refer to schematic number J0638-8.

Fuse and Display Module Parts Lists

M43534-3 FUSE MODULE

Q42866-6 CHANNEL 2 FUSE MODULE

M43530-1 LED ASSEMBLY “SUPPLY”

Q43061-3 ODEP DISPLAY MODULE
CAPACITORS

DIODES

LED’S

RESISTORS

R508 R608 A10266-1351 1.3M
R509 R609 A10266-4751 4.7M
R510 R610 A10266-4751 4.7M
R511 R611 A10266-4741 470K
R512 R612 A10266-2221 2.2K
R513 R613 A10266-1522 1.5K .5W
R514 R614 A10266-1001 10
R615 A10266-1522 1.5K .5W
R702 R802 A10266-5111 510

TRANSISTORS

Q42549-8 Output Module (P10115-7 board) Parts List
CAPACITORS

DIODES

INDUCTORS

TRANSISTORS

RESISTORS

Note: R30 is 102 Ohms in most units, though in some cases a different value may be used to match the installed S100/S200 LM334 (C5826-0) device grade. This is the standard value and is used with the most common LM334 grade, green. If the LM334 is marked with a blue dot, R30 should be a 107 Ohm resistor (A10265-10701); if it is marked with a yellow dot then R30 should be a 100 Ohm resistor (A10265-10001).
Q42647-0 Output Module (P10137-1 board) Parts List
CAPACITORS

DIODES

INDUCTORS

TRANSISTORS

RESISTORS

Note: R30 is 102 Ohms in most units, though in some cases a different value may be used to match the installed S100/S200 LM334 (C5826-0) device grade. This is the standard value and is used with the most common LM334 grade, green. If the LM334 is marked with a blue dot, R30 should be a 107 Ohm resistor (A10265-10701); if it is marked with a yellow dot then R30 should be a 100 Ohm resistor (A10265-10001).

Q42717-1 Output Module (P10233-8 board) Parts List
CAPACITORS

DIODES
D01| C 2851-1| 1N4004
D02| C 2851-1| 1N4004
D03| C 2851-1| 1N4004
D04| C 2851-1| 1N4004
D05| C 2851-1| 1N4004
D06| C 2851-1| 1N4004
D07| C 2851-1| 1N4004
D08| C 2851-1| 1N4004
D09| C 2851-1| 1N4004
D10| C 2851-1| 1N4004
D11| C 2851-1| 1N4004
D12| C 2851-1| 1N4004

INDUCTORS

TRANSISTORS

RESISTORS

Note: R30 is 102 Ohms in most units, though in some cases a different value may be used to match the installed S100/S200 LM334 (C5826-0) device grade. This is the standard value and is used with the most common LM334 grade, green. If the LM334 is marked with a blue dot, R30 should be a 107 Ohm resistor (A10265-10701); if it is marked with a yellow dot then R30 should be a 100 Ohm resistor (A10265-10001).

Q42871-6 Output Module (P10305-4 board) Parts List
CAPACITORS

DIODES
D01| C 2851-1| 1N4004
D02| C 2851-1| 1N4004
D03| C 2851-1| 1N4004
D04| C 2851-1| 1N4004
D05| C 2851-1| 1N4004
D06| C 2851-1| 1N4004
D07| C 2851-1| 1N4004
D08| C 2851-1| 1N4004
D09| C 2851-1| 1N4004
D10| C 2851-1| 1N4004
D11| C 2851-1| 1N4004
D12| C 2851-1| 1N4004

INDUCTORS

TRANSISTORS
Q17| C 3810-6| MPSA43
Q19| C 3578-9| MPSA93

RESISTORS

Note: R30 is 102 Ohms in most units, though in some cases a different value may be used to match the installed S100/S200 LM334 (C5826-0) device grade. This is the standard value and is used with the most common LM334 grade, green. If the LM334 is marked with a blue dot, R30 should be a 107 Ohm resistor (A10265-10701); if it is marked with a yellow dot then R30 should be a 100 Ohm resistor (A10265-10001).

Q42968-0 Output Module (P10341-9 board) Parts List
CAPACITORS

DIODES
D01| C 2851-1| 1N4004
D02| C 2851-1| 1N4004
D03| C 2851-1| 1N4004
D04| C 2851-1| 1N4004
D05| C 2851-1| 1N4004
D06| C 2851-1| 1N4004
D07| C 2851-1| 1N4004
D08| C 2851-1| 1N4004
D09| C 2851-1| 1N4004
D10| C 2851-1| 1N4004
D11| C 2851-1| 1N4004
D12| C 2851-1| 1N4004
INDUCTORS

L00| D 6592-6| Output Coil
L01| C 3510-2| 470µH
L02| C 3510-2| 470µH
TRANSISTORS
Q17| C 3810-6| MPSA43/42
Q19| C 3578-9| MPSA93

RESISTORS

Note: R30 is 102 Ohms in most units, though in some cases a different value may be used to match the installed S100/S200 LM334 (C5826-0) device grade. This is the standard value and is used with the most common LM334 grade, green. If the LM334 is marked with a blue dot, R30 should be a 107 Ohm resistor (A10265-10701); if it is marked with a yellow dot then R30 should be a 100 Ohm resistor (A10265-10001).

Q43202-3 Output Module (P10397-1 board) Parts List
CAPACITORS

DIODES
D01| C 2851-1| 1N4004
D02| C 2851-1| 1N4004
D03| C 2851-1| 1N4004
D04| C 2851-1| 1N4004
D05| C 2851-1| 1N4004
D06| C 2851-1| 1N4004
D07| C 2851-1| 1N4004
D08| C 2851-1| 1N4004
D09| C 2851-1| 1N4004
D10| C 2851-1| 1N4004
D11| C 2851-1| 1N4004
D12| C 2851-1| 1N4004
INDUCTORS

L00| D 6592-6| Output Coil
L01| C 3510-2| 470µH
L02| C 3510-2| 470µH
TRANSISTORS
Q17| C 3810-6| MPSA43/42
Q19| C 3578-9| MPSA93
RESISTORS

R00| A10266-7501| 75
R01| A10266-4711| 470
R02| C 7778-1| 5.6 FP
R03| C 6486-2| .2 5W
R04| C 6486-2| .2 5W
R05| C 6486-2| .2 5W
R06| C 6486-2| .2 5W
R07| C 6486-2| .2 5W
R08| C 6486-2| .2 5W
R09| C 7779-9| 22 FP
R10| A10266-4711| 470
R11| A10266-2R74| 2.7 2W
R12| A10266-1204| 12 2W
R13| A10266-7501| 75
R14| A10266-1204| 12 2W
R15| C 6486-2| .2 5W
R16| C 6486-2| .2 5W
R17| C 6486-2| .2 5W
R18| C 6486-2| .2 5W
R19| C 6486-2| .2 5W
R20| C 6486-2| .2 5W
R21| C 7778-1| 5.6 FP
R22| C 7779-9| 22 FP
R23| C 6844-2| 250 Pot
R24| A10266-1331| 13K
R25| A10266-2221| 2.2K
R26| C 6844-2| 250 Pot
R27| A10266-3911| 390
R28| A10266-1331| 13K
R29| A10266-5101| 51
R30| A10265-10201| 102*
R35| A10266-1204| 12 2W
R36| A10266-1204| 12 2W
R37| A10266-1204| 12 2W
R38| A10266-1204| 12 2W
R39| A10266-1204| 12 2W
R40| A10266-1204| 12 2W
MISC| |
---|---|---
Board| P10397-1|
Jumpers| C 5868-2| 0 Ohm (7)
Clips| D 6414-3| Q17/Q19
J500 J600| C 7057-0| 10 Pin HDR

Note: R30 is 102 Ohms in most units, though in some cases a different value may be used to match the installed S100/S200 LM334 (C5826-0) device grade. This is the standard value and is used with the most common LM334 grade, green. If the LM334 is marked with a blue dot, R30 should be a 107 Ohm resistor (A10265-10701); if it is marked with a yellow dot then R30 should be a 100 Ohm resistor (A10265-10001).

Q42552A0 Main Module (D6304A4/D6304B2 board) Parts List
CAPACITORS

DIODES
D1| | C 2851-1| 1N4004
D2| | C 2851-1| 1N4004
D3| | C 2851-1| 1N4004
D4| | C 2851-1| 1N4004
D5| | C 2851-1| 1N4004
D6| | C 2851-1| 1N4004
D7| | C 2851-1| 1N4004
D104| D204| C 2851-1| 1N4004
D105| D205| C 2851-1| 1N4004
D106| D206| C 2851-1| 1N4004
D107| D207| C 2851-1| 1N4004
D108| D208| C 3181-2| 1N4148
D109| D209| C 3181-2| 1N4148
D110| D210| C 3181-2| 1N4148
D111| D211| C 3181-2| 1N4148
D112| D212| C 3181-2| 1N4148
D113| D213| C 3181-2| 1N4148
D114| D214| C 3181-2| 1N4148
D115| D215| C 3181-2| 1N4148
D120| D220| C 3181-2| 1N4148
D121| D221| C 3181-2| 1N4148
D122| D222| C 3181-2| 1N4148
D123| D223| C 3181-2| 1N4148

RESISTOR NETWORKS

TRANSISTORS

RESISTORS

SWITCHES

INTEGRATED CIRCUITS

CONNECTORS

MOUNTS U1, U2
(2) C 1889-2 6-32 NUT
(2) C 2176-3 6-32 X .5 SCREW
(2) C 5341-0 HEATSINK
(2) C 5594-4 STAR WASHER
MOUNTS U104, U204
(2) C 3450-1 14 PIN SOCKET
COVERS FOR J100, J200
(2) C 6778-2 COVER, PHONE JACK
MISC
(1) C 4508-5 16 PIN SOCKET
(1) C 5061-4 1N3070 DIODE
(1) C 6851-7 5-Position .1 Center Header
(1) C 7077-8 3-Conductor Wire Retainer C 6899-6 Wire Posts
BLANK CIRCUIT BOARD D 6304A4 or D 6304B2

Q42714-8 Main Module (D 6910-0 board) Parts List

CAPACITORS

RESISTOR NETWORKS

TRANSISTORS

RESISTORS

SWITCHES

INTEGRATED CIRCUITS

CONNECTORS

Q42776-7 Main Module (D 7251-8 board) Parts List
CAPACITORS

DIODES

RESISTOR NETWORKS

TRANSISTORS

RESISTORS

SWITCHES

INTEGRATED CIRCUITS

CONNECTORS

MISC
MOUNTS U1, U2:

MOUNTS U104, U204:
(2) C 3450-1 14 Pin Skt.
COVERS FOR J100, J200:
(2) C 6778-2 Ph. Jk. Cvr.
STRAIN RELIEF:
(4) C 1811-6 Cable Tie
CIRCUIT BOARD:
D 7251-8

Q42980-5 Main Module (D7911-7 board) Parts List
CAPACITORS

DIODES

RESISTOR NETWORKS

TRANSISTORS

RESISTORS

SWITCHES

INTEGRATED CIRCUITS

CONNECTORS

MISC
MOUNTS U1, U2:

IC SOCKETS:
(6) C 3450-1 14 Pin Skt.
COVERS FOR J100, J200:
(2) C 6778-2 Ph. Jk. Cvr.
STRAIN RELIEF:
(4) C 1811-6 Cable Tie
CIRCUIT BOARD:
D 7911-7

Q43035-7 Main Module (D7993-5 board) Parts List

CAPACITORS

DIODES

TRANSISTORS

RESISTOR NETWORKS

RESISTORS

R133 R233 A10266-2741 270K
R134 R234 A10266-1832 18K .5W
R135 R235 C 7782-3 100 Flame Proof
R136 R236 A10266-6821 6.8K
R137 R237 C 7782-3 100 Flame Proof
R138 R238 A10266-6821 6.8K
R139 R239 A10266-8211 820
R140 R240 A10266-6801 68
R141 R241 A10266-1541 150K
R142 R242 A10266-1541 150K
R143 R243 A10266-1041 100K
R144 R244 A10266-1041 100K
R145 R245 A10266-1851 1.8M
R146 R246 A10266-1031 10K
R147 R247 C 7781-5 200 .5W Flame Proof
R148 R248 A10266-2721 2.7K
R149 R249 C 7781-5 200 .5W Flame Proof
R150 R250 A10266-2721 2.7K
R151 R251 A10266-1031 10K
R152 R252 A10265-11821 11.8K 1%
R153 R253 JUMPER JUMPER
R154 R254 C 8261-7 121K 0.1%
R155 R255 A10266-1321 1.3K
R156 R256 A10266-1321 1.3K
R157 R257 A10266-1321 1.3K
R158 R258 A10265-11321 11.3K 1%
R159 R259 A10266-1021 1K
R160 R260 C 8260-9 10K 0.1%
R161 R261 A10266-4701 47
R162 R262 A10266-4701 47
R163 R263 C 8261-7 121K 0.1%
R164 R264 C 8260-9 10K 0.1%
R165 R265 C 8261-7 121K 0.1%
R166 R266 A10266-1851 1.8M
R167 R267 A10265-10011 1K 1%
R168 R268 A10265-97601 976 1%
R170 R270 A10265-10011 1K 1%
R171 R271 A10265-95301 953 1%
R173 R273 C 8260-9 10K 0.1%
R174 R274 A10265-24921 24.9K 1%
R175 R275 A10265-11521 11.5K 1%
R176 R276 A10265-24921 24.9K 1%
R177 R277 A10265-40221 40.2K 1%
R179 R279 A10266-1321 1.3K
R180 R280 A10266-4711 470
R181 R281 A10266-4721 4.7K
R182 R282 A10266-2201 22
R183 R283 A10266-2421 2.4K
R184 R284 A10266-4741 470K
R185 R285 A10266-2421 2.4K
R186 R286 A10266-2751 2.7M
R187 R287 A10266-3631 36K
R188 R288 A10266-3631 36K
R189 R289 A10266-2731 27K
R190 R290 A10266-2051 2M
R191 R291 A10266-3331 33K
R192 R292 A10266-1031 10K
R193 R293 A10266-1031 10K
R194 R294 A10266-1041 100K
R195 R295 A10266-3021 3K
R196 R296 A10266-4721 4.7K
R197 R297 A10266-1031 10K
R198 R298 A10266-4721 4.7K
R199 R299 A10266-1031 10K
R909 R1009 A10266-4741 470K
R910 R1010 A10266-4741 470K
R911 R1011 A10266-1521 1.5K
R912 R1012 A10266-4711 470
R913 R1013 A10266-1051 1M
R914 R1014 A10266-1051 1M
R915 R1015 A10266-3901 39
R916 R1016 A10266-3901 39
R917 R1017 A10266-10021 10K
R918 R1018 A10266-10021 10K
R919 R1019 A10266-10021 10K
R920 R1020 A10266-10021 10K
R921 R1021 C 9079-2 200 Pot (CMR Null)

SWITCHES

Q43031-6 Main Module (D7993-5 board) Parts List

CAPACITORS

DIODES

TRANSISTORS

RESISTOR NETWORKS

RESISTORS