Discussion about the Korg PolySix synthesizer

Hi,

How to determine the pin number of an IC:

e.g. DIL-8 case:


          8 7 6 5
         +|-|-|-|+
notch:  >       |
         +|-|-|-|+
          1 2 3 4
          ^
pin no. one

I hope this helps ...

ciscomanvann wrote:
> OK, when I am looking at the IC how do i know which pin is pin 1? I
> found one pin on IC12 that measures +/- 4.7 v but no pin that changes
> on IC13. Hmm
> 
> --- In PolySix@yahoogroups.com, Johannes Hausensteiner <jo.synth@c...>
> wrote:
> 
>>On KLM-367 check the following:
>>* IC12 (TL072) pin1: must be -5V .. +5V according to PW/PWM poti
>>   if not, replace IC12
>>* IC13 (4558) pin1: must be -5V .. +5V according to PWM SPEED poti
>>   if not, replace IC13
>>* Set PWM SPEED to slowest and check IC1 (4066)/pin9: must change from
>>   minus to plus voltage and back (I dont know the exact values; will
>>   be at least -3V..+3V)
>>   if not, replace IC20 (LM13600) and/or IC15 (4558)
>>* IC1/pin6: must be +5V when WAVEFORM is at PWM position, otherwise 0V.
>>   if not, replace IC3 (LM339)
>>* IC1/pin8: must be the same as IC1/pin9 when WAVEFORM is at PWM
>>   position, if not replace IC1 (4066).
>>* TP1 (PW/PWM) near IC12: according to service manual "PW/PWM check
>>   and adjustment"
>>   if not OK, replace IC20 (LM13600) and/or IC15 (4558)
>>
>>I hope this helps,
>>
>>Johannes
>>
>>
>>ciscomanvann wrote:
>>
>>>Nothing happens. It plays, but the width or pwm does not change. I 
>>>have a multimeter, how do i check this stuff out? I dont know a whole 
>>>lot about ICs.
>>>
>>>--- In PolySix@yahoogroups.com, The Old Crow <oldcrow@o...> wrote:
>>>
>>>
>>>> First thing to do is set VCO to PW and move the width knob from 0 
>>>
>>>to 10 
>>>
>>>
>>>>and back to 0 and listen to see if it changes accordingly.  Then 
>>>
>>>set it to 
>>>
>>>
>>>>10 and change the VCO mode to PWM and move the PWM speed knob from 
>>>
>>>0 to 10 
>>>
>>>
>>>>slowly and note if the cyclic modulation is audible.
>>>>
>>>> If nothing is working then I would imagine either IC20 (LM13600) 
>>>
>>>needs 
>>>
>>>
>>>>replaced, or the analog switch section IC1C died and IC1 needs 
>>>
>>>replaced, 
>>>
>>>
>>>>or perhaps the control voltages off deMUX IC19 aren't getting there 
>>>
>>>and 
>>>
>>>
>>>>IC19, IC12 or IC13 is to blame (least likely though).
>>>>
>>>> Use my schematic as it is much easier to read than the old 
>>>
>>>service 
>>>
>>>
>>>>manual copy.  PWM circuit is on the far right, about 2/3 of the way 
>>>
>>>down.  
>>>
>>>
>>>>It is marked "PWM MG":
>>>>
>>>>
>>>
>>>http://www.oldcrows.net/~oldcrow/synth/korg/polysix/crowlm367/klm367a_
>>>eagle_schem.gif
>>>
>>>
>>>> Hope this helps,
>>>>
>>>>Crow
>>>>/**/
>>>>
>>>>On Wed, 31 Dec 2003, ciscomanvann wrote:
>>>>
>>>>
>>>>
>>>>>I know this sounds stupid, but how can i tell if the PWM is 
>>>
>>>working?
>>>
>>>
>>>>>If it is not, where do I start looking to fix it?
>>>>>Thanks!
>>>
>>>
>>>
>>>PolySix "Digiest" Page: http://www.acc.umu.se/~amber/Poly6 
>>>
>>>Yahoo! Groups Links
>>>
>>>To visit your group on the web, go to:
>>> http://groups.yahoo.com/group/PolySix/
>>>
>>>To unsubscribe from this group, send an email to:
>>> PolySix-unsubscribe@yahoogroups.com
>>>
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>>> http://docs.yahoo.com/info/terms/ 
>>>
>>>
>>>
>>>
> 
> 
> 
> PolySix "Digiest" Page: http://www.acc.umu.se/~amber/Poly6 
> 
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> 
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> 
> 
>