EMSA_Synthi-Aks_Service_Manual 电路图.pdf

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1、STNTHI-AES Circuit Diagrams and Layouts from ,11 North Main P.O. Box 439 Williamsburg, MA. 01096 268-3588 RadioFans.CN 收音机爱 好者资料库 J INDEX 1. Address clock I 2. Address clock + Touch Sensitive KB. 3. Touch Sensitive KB. J *f. Touch Sensitive KB. -. -5. Touch Sensitive KB. 6. D Type Short Term Memory.

2、 1 7. D Type Short Term Memory. 8. Random Touch Pad and Clock + Real Time DAC. J 9 Record And Play Touch Pads + Dynamic Function + Envelope Trigger -| 10 Record And Play Touch Pads + Memory Control Logic. 11. Shift Register Memory + Gates. B: 12. Shift Register Memory + Clock Generator -Skipshift. 1

3、3* Meter DAC + Clock Generator -Skip And Shift. J 14. Memory DAC + Transposition Pads + Shift Ani Skip. I 15 Transposition Pads. 16. Transposition Pads + Appendix. J Back Page. Shift Register. MF5OO52T. or MF71CA. RadioFans.CN 收音机爱 好者资料库 The pulses generated are used to compile various gating signal

4、s. . : The signal is divided by 2 by E22 (8,9,11,12) and again by 2 by E22 (2,3f5f6), and thenby 16 by E23. By gating these signals together, a set of waveforms shown below is produced. imnnnnnnnn * * en N nnnnnn nnnnnnnnnnn in U U U U U U V/T */ fit, SIGNALS A1f AOf BO, CO provide a four bit addres

5、s code to the three data multiplexers* The top two multiplexers, E15, E27 are connected to the keyboard, and as only 30 notes are provided, then two inputs (E27 ps 7f8) are left permanently unconnected# The lower multiplexer is the transposition pad unit. RadioFans.CN 收音机爱 好者资料库 MULTIPLEXERS -an ele

6、ctronic 16 way switch; single pole, The 16 inputs; EO to E15f can be considered as the 16 inputs to a rotary switch* The switch position * (only 6ne pole) is determined by the address code.ieAO A1 B1 C1. labelled ABCD on the actual device. .Where 0 = low voltagd ) . . , 1 = high voltage ) 1 no jump

7、as above * 1 c i. 11. Lines A and B open and cose the sets of input/output gates. Only one set of gates (A or B) is ever open. When the logic level on A is high, gates connected to it are open. When the logic level on A is lowf gates connected to it are closed. fe Mc 15V dc max into 10K ohm Signal I

8、nput; ac -1.8V p.p into 50K ohm. dc-2.5V max into 50K ohm. Microphone Input; 5raV into 600 ohms Devices Oscillator 1 Range: lHz-lOkHz (on dial) Outputs: Sine 2V p.p (with shape control) Sawtooth 2V p.p Control Sensitivity; 0.32 Volts/Octave Oscillator 2 . Range; lHz-lOkHz (on dial) Outputs: TriangJL

9、e/Sawtooth 3V p.p Square/Pulse 2V p.p Control sensitivity; 0.32 Volts/octave Oscillator 3 Range: 0.02(40lfperiod) -500Hz(on dial) Outputs: Triangle/Sawtooth 3V p.p Square/Pulse 2V p.p Control Sensitivity: 0.26 Volts/octave Noise Generator Level: 3V p.p white and coloured Filter/Oscillator Range: 5Hz

10、-10kHz (on dial) Cut-off rate: 18 dB/Octave Q: Variable up to 20 Frequency Control : 0.2Volts/0ctave Ring Modulator Input level: 1.5V p.p max. Output level: 6V p.p max. Input rejection: -50 dB (with 1.5V p.p input) Envelope Shaper Duration: Attack 2ms-ls On 0-2.5s Decay 3ms-15s Off 10ms-5s (+Off pos

11、ition) Trapezoid Output: 3V dc max. Decay Control; 0.4 Volts/octave Reverberation Max time: 2s Output Level: 5V p.p Mix VC : -2V for 0%, +2V for 100% mix Joystick: Voltage Output: 2 x il.5V dc Meter Input Control Voltage mode: 1V dc Signal mode: 4V p.p Input Amplifiers Sensitivity: 1.8V for High Lev

12、el Inputs 5mV for Microphone Inputs Output Amplifiers Output level: 2V p.p into 500 ohm (panned) 10V p.p into 50.ohm (unpanned) 5V dc into 10K ohm (unpanned VC level: 15 dB/Volt I3FT N MAINS PLUG V . 4LL MAINS POWEP PACK Mains Voltacc r SKI + I2v f /to rever power amps thence to revere. to power amp

13、s and reverb. I2v regulailor pbWeramps. NOTE. When testing board A by itself a 2OOn resistor should be put across the 12v, -9v lines. y level ccts. Jevel.ccts.;a|r L - -P- WIRE LINK GROUND BUS PC. BUS-AO.BOt ? Power Supply Before turning on, set PR1 cw and PR2 ccw with only A board plugged-in. Set P

14、R2 for +12V 0.1V Set PR1 for -9V 0,1V Check PR2 again and reset if necessary N.B. -9V rail is parasitic on the +12V supply. Plug in B and C cards and recheck +12V and -9V rails. These should not have altered. If they have, suspect either B or C board cr poor regulation on A board. Plug-ni keyboard a

15、s extra load. +12 and -9 Volt rails should not have moved more than 0.1V measured always on the A board. ( C board voltage may be 20 mV lower) Monitor the rails on the scope (5raV/cm). Look for hum and noise. These should be much less than 5mV. Noise, if present, will probably be due to the zener di

16、ode. Power supplies should stabilise on full load for specified fluctuations. 110/240 nominal : +10% or -23% * 110 nominal : 100V-135V for 125 sufficient 240 V nominal: 200V-260V Hum can also be checked by the following: Check Output Filters on 10 Output Controls on 10.0.10.10 Patchboard vacant Moni

17、tor (5mV/cm) on signal output Load unit with keyboard 100 Hz ripple as shown. Noise can be seen which should never exceed lOmV p.p. Even with noise level up. With noise level down, the noise on this waveform should be quite low. Zener diode noise will be very obvious. N.B. A2 normally gets hot, dodg

18、y Dl gives large lOOHz ripple on Output. Always clean edge-connectors and check clean presets on A board. 5mV . 2mV typ. ALL 2m S7Z Ch_L Tone Control F.E.TMod. Iw. Amplifier control, voltaae summer. Tone control. Ch.2, Control F.E.T Mod. voltage summer Iw. Amplifier. PBI7 10 Output Channels Set Outp

19、ut Channel Filters to 5. Set Output Level row to 0.0.10.0 and connect traces of scope (5mV/cm) to both signal outputs. Connect full level ramp signal at 261 Hz from Oscillator 1 to both Outputs. Trim PR4 and PR5 for minimum signal breakthrough. (Maximum 5mv p.p) Replace presets if adjustment is erra

20、tic. Reset Output Channel row controls to 5.0.10.5. Output levels should be around IV p.p and should be within 20% of each other. Check signal tracking in the same manner for Output settings 4 and 6 as well. If one level is consistently high, pad out resistor across its control pot (R305 = 56K) Succ

21、essful tracking will depend on the characteristics of the pots and the correct matching of the FETs Q14 Q18. Connect the joystick row via two shorting pins to both VC level inputs. Swing stick up and down to check for 20% level! tracking tolerance.(Level pots should be at zero). Inaccuracies in stic

22、k tracking may be adjusted by altering the value of R302 or R304 (10K) which are mounted under the patchboard rear. Check correct operation of Pan controls, which only affect the Signal Outputs. Check also the Output Filters. Use noise as a gcod source. Check for max. outputs on the Signal Output so

23、cket of at least 2.5V p.p before the onset of clipping. Level controls should be at about 6. Check headphone signal is good. Check for instability of Output Amps by driving hard with low frequency. (Oscillator 3 square wave). The level control of the channel NOT beirg driven should be on zero. Monit

24、or the two signal outputs. The undriven channel will show breakthrough. Plug in headphones and check for oscillation. Reduce drive to Output Channel 2. Keep checking for oscillation. Then repeat for other Output Channel. N.B. DC offset across loudspeaker is 1.8V. 10%. Hi-Zo drive amplifier. Pick-up

25、amplifier D38t Vj are off, C1 and C1X charged up by way of Pins 1,2,5 until upper threshold voltage (about +1.7v) is reached, the schmitt then fires, Pin 6 goes low, D38f *3 turn on and discharges C1 and C1X until the lower threshold voltage (about 0.9v) is reached. The schmitt then reverts back to

26、its original state etc.etc. +3 m tt i K./:- B.f J C-7 . _ .1 Org NO IO2/2. *l 39/ 90 ?-Is-: mmMcfMm I /-.NL . WMl t. 111 ? i ; | f i j f i %. *. _/ :v . /; tvN.n ?M y .-ir:.- :/ r. /- ai-X y? -c - *i I 4 l .r/ r, v .- . . -I. uuumi *#3l- M jl -4 _ _ _ - r V - j ps . c , j t p . I :-? /: j DRG. No. 23/oa THIRD ANGLE PROJECTION ALTERATIONS 5 Q14 CQI5 CIO, . 12 * j / 3. . *.x. . I I i i! ss: 5 .5 0 -! TOLERANCE. INCH METRIC 3 FIGURE =* -00S 2 -at-010 =t -I I TITLE COMPONENT LAYOUT DK 2 *! ?i * p .- illlffli-ll,! ; ; 4 L L I L I I I I I I I r r i r