MINIMOOG-D_SERVICE_MANUAL电路图.pdf

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1、- 1 - The minimoog MODEL D TECHNICAL SERVICE MANUAL by R. J. Folkman CONTROLLERS OSCILLATOR BANKMIXERMODIFIERSOUTPUT ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? moog MUSIC INC. t

2、he first sound in synthesizers RadioFans.CN 收音机爱 好者资料库 - 2 - MINI-MOOG Field Service Manual CONTENTS SectionTitlePage I Precautionary Measures 2 IISub-assembly Descriptions 3 III Block Diagram 5 IV Trouble Analysis Guide 6 V Sub-assembly Locations 8 VI Cover Removal and Sub-assembly Replacement 9 VI

3、I Adjustment Procedures and Locations 10 VIII Keyboard Maintenance 14 IX Schematic Diagrams 15 X Component Location Charts 16 XI Replacement Parts 17 XII Modifications 18 XIII Ordering and Shipping Instructions 19 Service Department Policy 20 7/73 RJF RadioFans.CN 收音机爱 好者资料库 - 3 - Section I: Precaut

4、ionary Measures In the Mini-Moog, as in any electrical device, shock hazards exist. All lethal voltages are confined to the area around the power switch and the A.C. fuseholder. Always unplug the instrument while servicing the electronics. Keyboard cleaning and adjusting may be done with the unit tu

5、rned on. When a fuse blows, replace it only with the proper size as indicated on the label directly below the fuseholder. If the fuse continues to blow, it is an indication that a definite electrical problem has developed. Never try a larger fuse; this will only result in further internal damage. Av

6、oid making adjustments at random. Each adjustment is critical and should be made in accordance with the procedures outlined herein. If a sub-assembly is found to be defective, we recommend exchanging it rather than attempting to repair it. Unless a qualified technician is available, with special tes

7、t fixtures, more harm than good may result and possibly void any remaining warranty. RadioFans.CN 收音机爱 好者资料库 - 4 - Section II: Sub-assembly Description 93-113 Oscillator (Board 1) This assembly contains three tone oscillators, summing amplifiers, exponential current generators, waveshaping circuits

8、and a -5 volt reference source. The three oscillators are independent and non-synchronous. Each oscillator is voltage controlled from external sources such as the keyboard. Linear input voltages are converted to exponential currents which are used to control the frequency or pitch of the tone produc

9、ed. The basic sawtooth signal is processed to derive triangle and variable width rectangular waveforms. Oscillator #3 has a wide range capability which enables it to be used for modulation purposes. The -5 volt reference source is used to establish the precise voltage steps on the octave range switc

10、hes. 93-114 Contour Generator (Board 2) This assembly contains two identical contour or envelope generators, and the keyboard circuitry. Upon triggering, the contour generators produce a voltage envelope with variable attack, decay, and sustain. The output is used to control the gain of the first vo

11、ltage controlled amplifier or the cutoff frequency of the voltage controlled filter. The keyboard circuit contains a constant current source which feeds the keyboard resistor string. This insures the proper voltage drop across each of the 43 keyboard resistors. Also contained on this assembly is the

12、 sample-hold circuit which measures the voltage from the keyboard and maintains it until a different key is depressed. The output of this circuit is the control voltage for the oscillators and the filter. The glide feature is a function of the sample-hold circuit. 93-115 Power Supply (Board 3) This

13、assembly contains the plus and minus 10 volt regulators, the headphone amplifier, the noise generator and the modulation mix amplifier. The plus supply uses a temperature compensated zener diode for a voltage reference. The minus supply is referenced to the regulated plus voltage causing the two sup

14、plies to track. Both supplies employ remote voltage sensing for optimum stability. The headphone amplifier is an A.C. coupled emitter follower with a push-pull output. The noise generator uses a reverse biased transistor junction for a noise source. The output of this transistor is processed through

15、 three filter circuits to derive the white, pink, and red noise outputs. The modulation mix amplifier takes signals from Oscillator #3 and the noise generator, sums them and supplies an output which is used for modulation. 93-116 Filter (Board 4) This assembly contains the voltage controlled filter,

16、 the external input pre-amplifier, the overload lamp driver, the first and second voltage controlled amplifiers and the A-440 reference oscillator. The filter is a voltage controlled low pass type which employs the Moog patented ladder network. It is capable of regenerating (oscillating) over a wide

17、 frequency range. The scale is adjustable so the filter can be set to track the keyboard. - 5 - The external pre-amp is a three transistor high-gain amplifier. The output of the pre-amp is monitored by an overload indicator. The overload driver circuit is a Schmitt trigger which turns the overload l

18、ight on when external signal levels become excessive. The first and second voltage controlled amplifiers are two nearly identical circuits. Their gain is controlled by varying the voltage which supplies the current source transistors. A buffer or output amplifier follows the second VCA stage. The A-

19、440 reference source is a highly stable Wein Bridge oscillator circuit. It produces a somewhat imperfect sinewave which increases its harmonic content. These harmonics or overtones assist in tuning to the reference, especially when the source being tuned is one or two octaves away from the reference

20、 frequency. The output of this circuit is coupled to the VCA buffer amplifier. 93-118 Rectifier Board This assembly contains the input bridge rectifier diodes and the unregulated D.C. filter capacitors. 93-060 Left Hand Controller This assembly contains the PITCH wheel, MODULATION wheel, GLIDE and D

21、ECAY switches, and two jacks for remote switching of glide and decay. The PITCH wheel has a mechanical detent which allows it to be easily returned to a pre-set tune point. To service this assembly, remove the two mounting screws and lift the unit out. All connections to this assembly are through a

22、12 prong plug to simplify servicing and replacement. 93-061 Keyboard The Mini-Moog keyboard is a standard three and one-half octave removable sub-assembly. All electrical contacts are gold plated for high reliability. The keyboard is held in place by four (4) mounting screws which are accessible whe

23、n the bottom cover is removed. All connections to this assembly are through a 6 prong plug to simplify servicing and replacement. - 6 - Section III: Block Diagram (This block diagram is a simplified version of the one from the Users Manual. The diagram from the service manual fits on a single 11x17

24、sheet.) 2/31/3 Noise Source OSC Control Tune Vol Wave Filter Contour A440 VCA 1VCA 2 Loudness Contour RiseRiseSus FallSus Fall 8ve 8ve 8ve Tune Tune Wave Wave Headphone Amplifier Volume Portamento Keyboard OSC 3 OSC 2 VCF Mic Preamp White Pink Modulation Mix Mix Glide Switch Glide Jack Freq OSC 1 Em

25、p Amt Mod Roller Pitch Roller S-Trig Decay Switch Main Out Pedal Pedal Mic Input High-Z Pedal Volume Decay Jack - 7 - Section IV: Trouble Analysis Guide Use this chart along with the block diagram (Section III) to determine which assembly or component is defective. MALFUNCTIONPROBABLE CAUSE AND CURE

26、 Unit dead (no pilot light)1. Blown A.C. fuse 2. Defective power switch 3. Defective line cord or plug Unit dead (pilot light on, overload light off) 1. Defective power supply (board 3) 2. Defective power transformer 3. Defective output amplifier (change filter board 4) Unit dead (pilot light and ov

27、erload light on) 1. Blown D.C. fuse 2. Defective power supply (board 3) Excessive hum and constant modulation of all signals 1. Defective rectifier diode on 93-118 assembly 2. Defective filter cpacitor on 93-118 assembly 3. Defective power supply (board 3) 4. Broken ground wire No output from any mi

28、xer source (A-440 output works) 1. Defective contour generator (board 2) 2. Defective VCA or filter (replace filter board 4) No oscillator output (noise works)1. Defective oscillator (board 1) One oscillator dead or malfunctioning, other two operating normally 1. Defective oscillator (board 1) Oscil

29、lators drift and exhibit poor tracking Refer to Section XII - Modifications under Oscillator Assembly Oscillator 3 modulates oscillator 1 or 2 with modulation switches off Refer to Section XII - Modifications under Power Supply Assembly Improper or missing waveform (any oscillator) 1. Defective osci

30、llator (board 1) 2. Defective waveform switch Noise source dead or producing poor quality noise 1. Defective noise transistor (Q15 on board 3) 2. Defective noise generator (replace power supply board 3) External input dead1. Defective pre-amp (replace filter board 4) Filter inoperative or malfunctio

31、ning1. Defective filter board 4 Filter regeneration weak or absent (EMPHASIS at 10) 1. Defective filter (board 4) 2. Regen. Cal. not adjusted properly - 8 - MALFUNCTIONPROBABLE CAUSE AND CURE Excessive drift or pitch change after key is released (greater than 1 semitone per minute) 1. Defective keyb

32、oard circuit (replace board 2) Loudness and/or filter contour generator operate improperly 1. Defective contour generator (board 2) No output at phones headphone jack (main output normal) 1. Monaural plug in stereo jack 2. Defective headphone amp (replace power supply board 3) Overload light fails t

33、o operate when excessive signal is applied 1. Defective bulb 2. Defective lamp driver circuit (replace filter board 4) Thumping sound heard when depressing a key (AMOUNT OF CONTOUR at 0) 1. First VCA out of balance Refer to Section VII - Adjustments 2. Defective VCA (replace filter board 4) 3. Refer

34、 to Section XII - Modifications, under contour generator assembly Keyboard glides when glide is off1. Defective keyboard circuit (replace contour generator board 2) Unit cannot be tuned (A-440 on frequency, within 1 Hz) 1. Defective oscillator (board 1) 2. Defective keyboard circuit (replace board 2

35、) Unit cannot be tuned (A-440 off frequency more than 5 Hz) 1. Power supply voltages improperly adjusted 2. Defective power supply (board 3) A-440 reference oscillator dead (other outputs normal) 1. Defective reference oscillator (replace filter board 4) No modulation (filter or oscillator)1. Defect

36、ive mod. mix amp. (replace power supply bd. 3) 2. Defective MODULATION wheel control Range switches have little or no effect 1. Octave Range misadjusted 2. -5 volt source defective (replace oscillator board 1) Noise or static when turning a control1. Control dirty spray clean 2. Control worn-out; re

37、place Noisy or intermittent switch1. Switch dirty spray clean 2. Switch worn-out; replace Intermittent operation or loss of some functions 1. Clean circuit board contacts with a pencil eraser 2. Tighten tension on circuit board sockets - 9 - Section V: Sub-Assembly Locations Power Supply 93-115 (Bd.

38、 3) Rectifier 93-118 Left Hand Controller 93-060 Contour Gen. 93-114 (Bd. 2) Keyboard 93-061 Oscillator 93-113 (Bd. 1) Filter 93-116 (Bd. 4) - 10 - Section VI: Cover Removal and Sub-assembly Replacement In order to service the Mini-Moog circuitry, it is necessary to remove the rear cover assembly. C

39、AUTION: Be sure the unit is unplugged before removing the cover. Remove 18 screws (5 top, 5 lower back, and 4 each end of cover); then lift the cover off. Circuit boards are plugged into sockets at the bottom and secured at the top with two mounting screws. To remove a circuit board, first remove th

40、e screws then unplug from the connector. When replacing, be sure board is firmly seated in the connector before tightening the mounting screws. Remember to re-install the fiber washers between the boards and the frame. After board replacement, refer to Section VII: Adjustment Procedures and Location

41、s, to determine which adjustments should be made. - 11 - Section VII: Adjustment Procedures and Locations Each time a Mini-Moog is serviced, it should be tuned. When a board has been replaced it will be necessary to make additional adjustments. Refer to the table below to determine which adjustments

42、 must be made according to the board that has been replaced. WHEN REPLACINGMAKE THESE ADJUSTMENTS 93-113 (Board 1) Oscillator1. Oscillator 1, 2, and 3 tuning 2. Octave range trimmer 93-114 (Board 2) Contour Generator1. Check tuning (adjust if necessary) 93-115 (Board 3) Power Supply1. +10 volts 2. -

43、10 volts 3. Noise level 4. Check tuning (adjust if necessary) 93-116 (Board 4) Filter1. VCA balance (1 and 2) 2. A-440 frequency 3. Regeneration cal. 4. Filter range 5. Filter scale 93-060 Left Hand Controller1. Check tuning (adjust if necessary) 93-061 Keyboard1. Check tuning (adjust if necessary)

44、- 12 - ADJUSTMENT PROCEDURES NOTE: The tuning and other functions rely heavily on accurate power supply voltages. Always be sure the + and - 10 volt supplies are properly set before making other adjustments. * Digital voltmeter with 0.1% accuracy TO ADJUST . . .FOLLOW THIS PROCEDURE . . . +10 voltsC

45、onnect an accurate D.C. voltmeter* to pins 1A and 2A on the oscillator (board 1). Adjust the +10 volt trimpot on the power supply (board 3) for +10.00 volts. -10 volts Connect an accurate D.C. voltmeter* to pins 2A and 3A on the oscillator (board 1). Adjust the -10 volt trimpot on the power supply (

46、board 3) for -10.00 volts. A-440 Ref. OscillatorTurn on A-440 and allow to warm up for two minutes. Adjust A-440 trim-pot on the filter (board 4) for zero beat with an A tuning fork. By bringing the struck tuning fork in physical contact with the shell of a pair of headphones, while listening to the

47、 A-440 output, the beat note becomes more audible. Oscillator Tuning (With Equipment) Connect a frequency counter to the High Main Output jack. Set the PITCH WHEEL to center, TUNE control to 0, RANGE switches to 2 ft., WAVE-FORM switches to SAWTOOTH. Set MIXER VOLUME controls to 4, turn OSCILLATOR M

48、ODULATION switch off, and OSCILLATOR 3 CONTROL switch on. Set Oscillator 2 and 3 FREQUENCY controls to mid- position. Turn on OSCILLATOR 1 mixer switch. Adjust Oscillator 1 Range Trimpot for 3520 Hz while holding high A key down. Depress low A and hold while adjusting Oscillator 1 Scale Trimpot for

49、440 Hz. Repeat until no further improvement is attainable. Turn off OSCILLATOR 1 Mixer switch. Turn on OSCILLATOR 2 and repeat the procedure - then OSCILLATOR 3. Finally, check tracking between any two oscillators and make any necessary touch-up adjustments to improve tracking. - 13 - TO ADJUST . . .FOLLOW THIS PROCEDURE . . . Oscillator Tuning (Without Equipment) Visualign Turn all MIXER switches off. Set MIXER VOLUMES at 1. Turn on MAIN