EFM_Wildcat_Service_Manual 电路图.pdf

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1、(c) EFM Wildcat EFM electronics for music The Wildcat is a modular system designed to be flexible enough to to build many types of synthesizers as well as remain unique. The most comprehensive system is naturally the most expensive to build. However the Wildcat board can also be used to construct a

2、much less expensive synthesizer. A full blown Wildcat Modular could cost more than $1000. The Wildcat Modular-1 was close to $600. About $100 went for ribbon cable and header- connectors. If you want to direct-wire and you already have or build your own case you can cut it down to under $500. As you

3、 read through this document you will see block symbols representing WildCat modules. This system allows WildCat builders to block-diagram their synthesizer. Say you would like plan your synth out before you build it. Now theres no reason to redraw all those schematics to fit your special purpose. Or

4、 you want build a web page to show off your synth when its finished. Usually you could not use EFM schematics or drawings on your site but I would really like to encourage the free use of these diagrams. Its all a matter of how much of the board you utilise and what type of hardware you use. Somethi

5、ng simple could be constructed for under $300. People who elect to direct-wire should note that it makes it impossible to remove the board. RadioFans.CN 收音机爱 好者资料库 (c) EFM Wildcat EFM electronics for music RadioFans.CN 收音机爱 好者资料库 Wildcat EFM electronics for music (c) EFM Power Supply The on-board 2

6、amp +/- 12 - volt power supply. The power rails run down the center of the board. There are 2 access headers to the right and another to the left. These are for testing purposes during construction and can be used for future expansion. Description The WildCat power supply provides plus and minus 12V

7、DC. When S1 is closed line level AC is applied to the 24V center tapped transformer. R1 and LED1 form a power on indicator. D1-4 form a full wave rectifier supplying about +/- 18VDC at filter capacitors C1 and C2. U1 is a variable-output positive voltage-regulator. R2 and T1 form a voltage divider C

8、4 is used as a capacitance multiplier. The voltage at the R2-T1 junction determine the regulators output voltage. D5 and D6 are for short circuit protection. Likewise U2 is a variable- output negative voltage-regulator. R3 and T2 form a voltage divider and C3 is used as a capacitance multiplier. D7

9、and D8 are for short circuit protection. RadioFans.CN 收音机爱 好者资料库 (c) EFM Wildcat EFM electronics for music Parts ? T1 24VCT Transformer (1) ? S1 SPST Power Switch (1) ? R1 2.2K 1% Resistor (1 ? R2.R3 120 Ohm 1% Resistor (2) ? T1,T2 5K 10T Trimmer (2) ? C1,C2 1000uF 35V Electrolytic Capacitor (2) ? C

10、3,C4,C5,C6 10uF 35V Electrolytic Capacitor (4) ? D1-D8 1N4001 Diode (8) ? U1 LM317 (1) ? U2 LM337 (1) Setup ?Equipment: Digital Multimeter ?Hook up a power LED. ?TIP: I used a PC-board header connector and soldered an LED to it so that I could remove it after testing. ?There are two 3-terminal power

11、 headers on the power supply rails labelled +, -, and GND. Set your meter to DC-Voltage and attach your probes. Turn S1 on and look for DC voltage at the power header. You should see something. If not check for DC voltage at D1 and D4. ?TIP: Use meter probes with removable mini- clips. Its so much e

12、asier than trying to hold probes while adjusting trimmers. ?Adjust T1 for +12V and T2 for -12V. (c) EFM Wildcat EFM electronics for music Midi to CV Converter Analog synthesizers are controlled by compatible control-voltages. ?CV - A control voltage is any voltage used to alter the operating paramet

13、ers of a module. This can range from -V to +V. ?Gate - Simply on and off. The time was when playing a analog synthesizers involved performing on analogcontrollers. Every piece had its own keyboard and there were all sorts of standards. Interfacing was a mess and you could forget about serious sequen

14、cing. The Midi to CV converter allows you to retain the flavor and feel of analog control using midi enabled devices. Inputs: ?Midi In Outputs: ?Midi Thru ?Pitch - Note ?Pitch Bend - PB Wheel ?Velocity - Note Pressure ?Gate - Note On-Off ?Mod - Mod Wheel ?Glide - Whenever more than one key is presse

15、d (c) EFM Wildcat EFM electronics for music Description The midi to CV converter uses a 7805 regulator for its +5V supply C1,C2 and C3 are bypass capacitors for voltage regulator U1. Midi is transmitted and received on a closed current loop U2 is a optical coupling device that converts the I/O state

16、 on the current loop into serial data the PIC microprocessor U3 can understand. The PIC puts the serial data together and uses the instruction to do a couple of things seemingly simultaneously. It seems simultaneous because the PIC is so fast however it does all of this one step at a time. Q1, Q2 fo

17、rm a non-inverting buffer that provides the midi- thru signal. Midi data, depending of the transmitting device can handle a lot of information we dont necessarily need to control an analog synthesizer and thats good because it makes doing the job with a low cost PIC possible. We can get by with fair

18、ly minimal set of controls. (c) EFM Wildcat EFM electronics for music ?Pitch ?Pitch Bend ?Velocity ?Gate ?Mod ?Glide The PIC loads the correct number into the DAC digital to analog converter U4 to generate a voltage that corresponds to the midi message received. Then selects which output is active b

19、y strobing the demux U5s select pins through the Q3-Q5 inverter-buffers. When one of the outputs goes high the voltage is sampled and held by capacitors C9-C14 until it is refreshed. U8a is the DAC output amp and U8b is the DAC voltage reference amplifier. NOTE: R1 is part of the power supply and no

20、t shown here. Parts C1-C2 0.1uF Ceramic Capacitor 2 C4 10uF16V 1 C5,C6 22pF Ceramic Capacitor 2 C7 10pF Ceramic Capacitor 1 C8 .01uF Poly Capacitor 1 C9-C14 0.1uF Mono Capacitor 6 R2,R9,R10 220 Ohm 1% Resistor 3 R3,R5,R16-R25 10K 1% Resistor 12 R4 1K 1% Resistor 1 R6,R7,R8 3.3K 1% Resistor 3 R11-R14

21、,R15 4.7K 1% Resistor 5 R26 47K 1% Resistor 1 R27 2.2K 1% Resistor 1 T1 50K 10T Trimmer 1 Q1,Q3-Q6 2N3906 5 Q2 2N3904 1 U1 7805 +5V Voltage Reg 1 U2 6N138 1 U3 PIC16F84 1 U4 AD7528 1 U5 CD4051 1 U6 LM358 1 U9 TLO72 2 U7 LM336Z 5.0V 1 U8 TLO74 1 S2 4 Position Dip Switch 1 J1,J2 5 Pin Din Panel Mount

22、Jack 2 Setup To generate a 1V/Octave scale the DAC needs the correct reference voltage. Adjust Trimmer T1 until the voltage on U4, pin-4 is -10.56V. (c) EFM Wildcat EFM electronics for music Glide The Glide or Lag module is a variable frequency low-pass filter. As the cutoff frequency is lowered the

23、 charge- time increases and sharp changes in voltage are smoothed. Generally used for pitch-lag (portamento) and smoothing the sample & hold output. Its called glide because it smoothes the transition from one note to another. Effectively gliding from one note to the next note played. Input: ?CV - I

24、n Output: ?CV - Out Description Voltage on the input charges C3 . P1 controls the charge rate. Parts ? C1,C2 0.1uF Ceramic Capacitor ? C3 1.0uF Mono Capacitor ? R1 1K ? U1 1/2 TLO72 (c) EFM Wildcat EFM electronics for music Slide The Slide module is much like the Glide module, performing the same so

25、rt of function it is however gated. Meaning that the preset lag time is bypassed unless the control input is held high or a gate voltage is present. Input: ?CV - In ?Rate - Lag Time ?Gate - On/Off Time Output: ?CV - Out Description P1 controls the charge rate of C3. Q1 is a bypass switch for P1. Q2

26、is a inverter, if the gate is low the collector is high holding Q3 on. If Q3 is on the collector voltage is low and Q1 is on or shorted, closing the circuit across P1. Removing P1 from the signal path. When a gate voltage turns Q2 on the collector is low. Q3s turns off, the collector goes high turni

27、ng Q1 off. If Q3 is off or open P1 is inserted into the signal path and controls the charge-rate. Parts ? C1 1.0uF Mono Capacitor ?R1 1K 1% Metal Film Resistor ?R2 100K 1% Metal Film Resistor ? R3,R4,R5 10K 1% Metal Film Resistor ?R6,* 1M 1% Metal Film Resistor ?P1 1M Potentiometer ?D1,D2 1N4148 Dio

28、de ?Q1 2N5460 P-Fet Transistor ? Q2,Q2 2N3904 NPN Transistor ?U1 1/2 TLO72 (c) EFM Wildcat EFM electronics for music VCOs 1-3 The voltage controlled oscillators are generally used to generate audio range signals but can easily be tuned to produce low frequency voltage for modulation purposes. There

29、are simultaneous saw, pulse, triangle and sine outputs. The FM input is a dedicated audio range input for high frequency modulation. It is used to produce ringing or bell like sounds. The Sync output is not usually used because sync can be obtained from the Saw or Pulse outputs. It produces a very t

30、hin pulse that in addition to sync can be used as a trigger other devices or modules. Inputs: CV1 - CV3 - 1 volt per octave CV inputs. CV4 - Frequency CV CV5 - Fine Tune CV FM - Audio Mod PW - Pulse Width PWM - Pulse Width Mod Sync - Sync In Note: Must be connected to -12V when not in use. Outputs:

31、Saw Pulse Triangle Sine Sync Description U1 and U2 from a linear voltage to exponential current sink. As current flows from the +V source C5 starts to charge. When the voltage at the output of buffer (U3a) reaches the threshold level of the comparator (U4a) it turns on . This turns Q1 on and shorts

32、C5 resetting it and the cycle begins again. This oscillation forms a sawtooth waveform on the output of buffer (U3a) An external input on the gate of the synchronisation transistor (Q2) causes the transistor to turn off and on shorting C5 regardless of whether U4a is on. Oscillation occurs in sync w

33、ith the controlling oscillator. An FM input causes the oscillator center frequency to change with the signal amplitude or Frequency Modulates the exponential converter. The sawtooth waveform is applied to the base of Q3. Q3 is a phase splitter and U3b combines the signals to form a triangle waveform

34、. The sawtooth waveform is also applied to the non-inverting input of comparator U4b. U4b is biased through R28 so that it turns on as soon as the voltage starts to rise at the output of U3a. The output of U4b is a variable pulse waveform A voltage applied to U4as inverting input changes the duty cy

35、cle altering the pulse width. The Sine output is formed by overdriving the input of Operational Transconductance Amplifier U6. Note: R27 is not used (c) EFM Wildcat EFM electronics for music (c) EFM Wildcat EFM electronics for music Setup ?If Q2 is installed make sure Pad-N is connected to -V. ?Turn

36、 all trimmers to their center positions. ?Attach a 50K Pulse-Width pot to pad R. Set the PW pot to 50% ?Attach header pin-P to a monitor amp with a level control and turn it way down. ?Hook up your midi keyboard to the midi in on the midi converter. ?Attach a jumper from the midi converters pitch ou

37、tput to header pin-C ?Turn the unit on and check for +V (U1 Pin-8) and -V (U1 Pin-4) ?Adjust T6 until the output is somewhere around 440Hz ?TIP: If you have a mute controller you can use a guitar tuning fork. ?Play low octave apart D notes and adjust T1 until they are in tune. ?Play high octave apar

38、t D notes and adjust T2 until they are in tune. ?TIP: You may have to go back and forth between T1 and T2 a few times to get it right. ?When the oscillator is in tune with itself re-adjust T6 for 440Hz ?Check the output pins B- Tri Q- Pulse P- Ramp A-Sine for signals. ?Tip: If you dont have a scope

39、use your monitor amp. ?Adjust T3 for the best looking/sounding sine. Parts C1,C2 0.1uF Ceramic Capacitor 2 C3,C4,C7 100pF Ceramic Capacitor 3 C5 0.01uF Mono Capacitor 1 C6 470pF Ceramic Capacitor 1 R1,R2,R3,R6,R29, R30,R32,R37 100K 1% Metal Film Resistor 9 R4 330K 1% Metal Film Resistor 1 R5,R10,R17

40、 1M 1% Metal Film Resistor 3 R7,R8,R28,R33,R35 22K 1% Metal Film Resistor 5 R9 1K Tempco 1 R11,R13,R14.R15,R16, R19,R21,R22,R23, R24,R26 10K 1% Metal Film Resistor 11 R12 470K 1% Metal Film Resistor 1 R18,R31 2.2K 1% Metal Film Resistor 2 R20 60K 1% Metal Film Resistor 1 R25,R34,R36,R40 1K 1% Metal

41、Film Resistor 4 R28 82K 1% Metal Film Resistor 1 R38 220K 1% Metal Film Resistor 1 R39 39K 1% Metal Film Resistor 1 T1,T2,T4 50K 10T Trimmer 3 T2 10K 10T Trimmer 1 P1,2,3,4,5 50K Potentiometer 5 Q1,Q2 J112 N-Fet Transistor 2 Q3 2N3904 NPN Transistor 1 U1,U3,U5 TLO72 Dual Opamp 3 U2 LM3046 Transistor

42、 Array 1 U4 LM393 Dual Comparator 1 (c) EFM Wildcat EFM electronics for music Mixer/Inverters 1-3 There are three 6-input mixers that can be used for audio, CV or a combination of both. There are normal and inverted outputs. Inputs: ?1-6 - Audio and/or CV inputs Outputs: ?Normal ?Inverted Descriptio

43、n When signals are present on the inputs U1a adds them together and outputs the inverted sum of all inputs. U1b is a simple inverting signal. Parts R1-R9 100K 1% Metal Film Resistor 9 U1 TLO72 Dual Opamp 1 (c) EFM Wildcat EFM electronics for music VCF-1 VCF-1 is a 4-pole Moog type transistor ladder

44、with low-pass and high-pass inputs. Notch can be obtained by splitting the input between both high and low inputs. This filter features voltage controlled resonance and several dedicated mixers. Inputs: ?HP In 1-2 ?LP In 1-3 ?Frequency CV 1-3 ?Cutoff parameter ?Resonance parameter ?Resonance CV Outp

45、uts: ?Audio Out Description due to temperature variations. The voltage applied to the base of the exponential-transistor causes a exponential collector current sink thats applied to the transistor ladder through R34. The ladder transistors are biased at increasingly positive potentials by the voltag

46、e divider string R14- 18 and R35. The bottom pair of transistors split the current supplied to R34 into equal parts when there is no audio on the base of the U1 (3,4,5) transistor. When audio is present both left and right sides of the ladder are modulated inversely.As current flow increases the col

47、lector impedance of the ladder transistors is decreased providing a higher cutoff frequency by form current to voltage converters that provide a voltage thats the log of the ladder current to reverse the non-linear effect audio signals cause on current within the ladder. This inverse modulation on t

48、he ladder causes a push-pull voltage to develop at the top of the ladder. A high pass input is provided by phase- splitting transistors Q1-Q2 connected to the top of the ladder. These voltages are applied to differencing and level shifting amplifier U2a and then to resonance vca U2b. The gain of U2b

49、 is set by bias current supplied by constant current source Q10 and Q11. The ratio of currents through these two transistors is a rough exponential function of the voltage difference between the bases. Current supplied from Q2 is reasonably constant and repeatable. The resonance signal must be dynamically are different. (c) EFM Wildcat EFM electronics for music Parts ?C1,C2 0.1uF Ceramic Capacitor 2 ?C3,C4 470pF Mono Capacitor 2 ?R1,R2,R3,R6,R7,R8, ?R11,R13,R16,R18 10K 1% Metal Film Resistor 10 ?R4,R5,R9,R10, 220 Ohm 1% Metal Film Resistor ?R12 47 Ohm 1