Discussion about the Korg PolySix synthesizer

DO NOT TOUCH IC12 !

If you're not looking for any further trouble... Johannes and me were 
just trying to solve a problem on my Trident on which that particular 
component was responsible... a 40-70$ priced unit and very hard to 
get. It is responsible for the overall scaling and tuning of the 
instrument. It is supposed to get hot indeed and has a built 
in "oven" which keeps it in a particular, stable temperature. My 
problem started when I tried to use a freezing spray to trying to 
find the cause for another problem, and unfortunately sprayed some 
onver it as well.... so stay away from it ;)


--- In PolySix@yahoogroups.com, "stagerhodes" <stagerhodes@...> wrote:
>
> Good tips which i will try for sure. I noticed the IC12 (10 leg 
> transistor type) in the signal board , will heat very quickly, is 
> this normal ? Since the Trident MK II has the outside dissipator 
> does the MK I need some extra thing to keep temperature 
controlled ? 
> The power supply triacs are heating as hell too... 
> oh, by the way...when for seconds the distortion is gone i have a 
> clue on how good this thing sounds...humm...great ! I can't wait to 
> have this beast in good shape..thanks!!! 
>  
> Johannes, the preset piano 1 started ok without deep changes in the 
> trim pots, it seems it was when i pressed the phillips screw driver 
> in order to turn the pot it started ok, but, after the distortion 
> came back i could't reproduce it again same way... 
>  
>  
> --- In PolySix@yahoogroups.com, Johannes Hausensteiner <johau@> 
> wrote: 
> > 
> > Hi, 
> >  
> > So the preset thing is clear; probably a "genius" cranked the 
> trimpots 
> > and made the sounds unusable. 
> >  
> > For the distortion: try to find out on what this depends. I would 
> start 
> > with a simple setting (e.g.only VCO-1, filter all open, "gate" 
EG, 
> etc.) 
> > Then play around with single parameters and notice under when the 
> > distortion/modulation starts. Maybe you can find out this way 
> where 
> > is comes from. 
> > Further check whether it is on all 8 voices. If yes, then 
probably 
> the 
> > reason is in a common part (e.g. overall synth gain circuit, ...) 
> >  
> > Voice #6: check IC9 of unit #6. On pin1 there should be the VCO-2 
> > waveform regardless of On/Off setting on the control panel. 
> IC9/pin13 
> > is the control signal, it should be high when VCO-2 is on, low 
> when 
> > off. IC9/pin2 is the switched VCO-2 wave. 
> >  
> > Good luck! 
> >  
> > Johannes 
> >  
> >  
> >  
> > stagerhodes wrote: 
> > > ok...i think i made some progress here...when trying to adjust 
> VR27  
> > > in the presets board (with piano 1 , as Johannes told) suddenly 
> i  
> > > heard the sound loud and clean...after a bit the distortion 
came  
> > > again...well, in this process when it sounded ok i changed 
from  
> > > piano 1 to manual and the synth was there without  
> > > distortion...but...no VCF working (just the FINE Cutoff was  
> > > working)...so i believe my problem is related with the 
> filter...i  
> > > will do more testing here, in the mean time if someone can give 
> some  
> > > clues based on this it would be great..thanks to all !  
> > > Oh..almost forgot...i found the VCO 2 not working in the voice 
> #6.  
> > >   
> > >  
> > > --- In PolySix@yahoogroups.com, "gil_we" <gil_we@> wrote: 
> > >  
> > >>Also, can you see any broken or "cold" solder joint on this 
> board ?  
> > >>  
> > >> 
> > >>--- In PolySix@yahoogroups.com, "gil_we" <gil_we@> wrote: 
> > >> 
> > >>>The Flanger board (KLM-291) is also the mixer board, in case 
it 
> got   
> > >>>defective it makes sense to me that the synth problem may be 
> related   
> > >>>to a defect on that board as well.  
> > >>>  
> > >>>Do you get that problem only, but only for the synth sound ?  
> > >>>  
> > >>>Does it sound distorted on both VCOs ? You can eliminte VCO1 
> and only   
> > >>>listen to VCO2 and vice versa ? 
> > >>>  
> > >>>  
> > >>>--- In PolySix@yahoogroups.com, "stagerhodes" <stagerhodes@> 
> wrote: 
> > >>>  
> > >>>>thank you !...well, the controls are working, only it makes a 
> kind of   
> > >>>>distortion which is more audible in the 16' and 8' octaves, 
it   
> > >>>>reduces it in the 4' ( a distortion with some kind of 
> modulation ),   
> > >>>>the bad effect will be more noticed too if one set the EG 
> Intensity   
> > >>>>to center or full counterclockwise (negative envelope). I 
> tried to   
> > >>>>memorize 2 patches and the programmer seems ok, the patches 
> are  
> > >>>>there, so i just don't know what to do next...  
> > >>>>I must say that it seems the top panel was (may be the unit 
> crashed   
> > >>>>in the floor or something) bend in the master tune pot area, 
> after a   
> > >>>>close look i saw one of the screws fixing the Flanger board , 
> in its   
> > >>>>place with a small PCB fragment attached, and the board broke 
> in one   
> > >>>>of its edges (screw area). I took out the flanger board and 
it 
> seems   
> > >>>>no damage in any of the pcb traces...anyway does any 
> malfunction in   
> > >>>>this board reflects in the synth section sound (with flanger 
> turned   
> > >>>>off) ??  
> > >>>>Oh, the preset sounds are not ok, just a short beep (low 
> frequency),   
> > >>>>the strings and brass are OK  
> > >>>>regards  
> > >>>>Art 
> > >>>>  
> > >>>>  
> > >>>>--- In PolySix@yahoogroups.com, Johannes Hausensteiner 
> <johau@> wrote: 
> > >>>> 
> > >>>>>The PCB looks OK; no damage due to leaked battery as in the 
> Polysix  
> > >>>>>is visible.  According to the pics (silkscreen) the battery 
> which is  
> > >>>>>mounted seems to be original or genuine replacement.  So I  
> would not  
> > >>>>>suspect a threat like in the P6.  It largely depends on the 
> battery  
> > >>>>>make, which seems to be good quality in this unit. So as 
long 
> as the  
> > >>>>>battery retains sufficient voltage (more than 2.5V) I would 
> not  
> > >>>>>worry about it.  
> > >>>>>This does not surprise me, since the Trident MK I programmer 
> and the  
> > >>>>>MK II programmer are completely different. MK I was designed 
> before  
> > >>>>>Polysix, MK II afterwards or the same time obviously using 
> the same  
> > >>>>>technique in both (edit mode, etc). Amazingly they did not 
> use a  
> > >>>>>microprocessor for the patch manager in the MK I but an 
> all-hardware  
> > >>>>>type of design.  
> > >>>>>  
> > >>>>>Regarding your original problem: it may be (even likely) 
that 
> the  
> > >>>>>battery is dead or at least discharged and all memory 
patches 
> are gone  
> > >>>>>producing no or meaningless sound. Are the knobs and 
switches 
> working  
> > >>>>>in "Manual" mode? How do the presets ("Piano 1", "Piano 2", 
> "Clav") sound?  
> > >>>>>  
> > >>>>>According to the schematics there are on KLM-317 three sets 
> of pots  
> > >>>>>for the presets; you may set your favourite sound patches 
> there.  
> > >>>>>(The Yamaha CS-60 and CS-80 had a similar kind of "Patch 
> Memory"..)  
> > >>>>>  
> > >>>>>Johannes 
> > >>>>>  
> > >>>>>  
> > >>>>>stagerhodes wrote: 
> > >>>>> 
> > >>>>>>Hi,  
> > >>>>>>just uploaded 8 photos of the board, hope they're ok now 
for 
> you to   
> > >>>>>>try to help me.  
> > >>>>>>regards,  
> > >>>>>>Art 
> > >>>>>> 
> > >>>>>>  
> > >>>>>>--- In PolySix@yahoogroups.com, "gil_we" <gil_we@> wrote: 
> > >>>>>> 
> > >>>>>>>you're welcome,  
> > >>>>>>> 
> > >>>>>>>I'm interested to see how corroded is the board - if any 
at 
> all. 
> > >>>>>>>  
> > >>>>>>> 
> > >>>>>>>--- In PolySix@yahoogroups.com, "stagerhodes" 
> <stagerhodes@y...> wrote: 
> > >>>>>>>  
> > >>>>>>>>Hi Gil,  
> > >>>>>>>>well, i'm not at home right now, but the battery is from 
> Sanyo, and   
> > >>>>>>>>the big lettering is CADNICA (nickel cadmium).  
> > >>>>>>>>I will take better pictures tonight and post them 
> (deleting the ones   
> > >>>>>>>>there now)...well, what can i say besides thank you for 
> your  
> > >>>>>>>>support ... 
> > >>>>>>>> 
> > >>>>>>>> 
> > >>>>>>>>--- In PolySix@yahoogroups.com, "gil_we" <gil_we@y...> 
> wrote: 
> > >>>>>>>>  
> > >>>>>>>>>It's very hard to see anything on those pictures... I do 
> see though   
> > >>>>>>>>>that the battery was already replaced ?? looks like a 
> lithium battery   
> > >>>>>>>>>what does it say on it ?  
> > >>>>>>>>> 
> > >>>>>>>>>Try to provide close up high resolution pictures of the 
> programmer 
> > >>>>>>>>>  
> > >>>>>>>>> 
> > >>>>>>>>>--- In PolySix@yahoogroups.com, "stagerhodes" 
> <stagerhodes@y...> wrote: 
> > >>>>>>>>>  
> > >>>>>>>>>>I think i have another problem here, not related with 
> battery leak,   
> > >>>>>>>>>>i just uploaded some photos , not very good quality, 
but 
> the battery   
> > >>>>>>>>>>seems to be sealed, and the programmer is working 
> despite some press   
> > >>>>>>>>>>memory recall buttons need cleaning or replacing. 
Well , 
> the synth   
> > >>>>>>>>>>sound has some distortion and sounds like ring 
> modulation, this is   
> > >>>>>>>>>>minimized if the negative/positive VCF EG Intensity is 
> full   
> > >>>>>>>>>>clockwise. The preset sounds are like no envelope 
> sustain, just a   
> > >>>>>>>>>>short low (frequency) click...well, i'm not a keyboard 
> technician,  
> > >>>>>>>>>>just trying to make something here, otherwise i will 
> have to take  
> > >>>>>>>>>>the synth and schematics to a friend who is a 
technician 
> (works in   
> > >>>>>>>>>>musical instruments, not vintage ones but...) and try 
to 
> put this   
> > >>>>>>>>>>synth to play...have to say the brass and strings 
> sections are ok,    
> > >>>>>>>>>>the split keyboard function switches and behavior are 
> ok, bend and   
> > >>>>>>>>>>mod ok...well...lets see 
> > >>>>>>>>>> 
> > >>>>>>>>>>  
> > >>>>>>>>>>--- In PolySix@yahoogroups.com, "gil_we" <gil_we@y...> 
> wrote: 
> > >>>>>>>>>>  
> > >>>>>>>>>>>Thanks,   
> > >>>>>>>>>>>  
> > >>>>>>>>>>>I believe that this type of info should be shared all 
> over the net.    
> > >>>>>>>>>>>The Trident's schematics are very rare - took me weeks 
> to get them;   
> > >>>>>>>>>>>however, here they are.   
> > >>>>>>>>>>>  
> > >>>>>>>>>>>I got my Trident in disasterous condition, nothing 
> worked, battery    
> > >>>>>>>>>>>corrosion, bad chips, everything you may think of... 
> Got it work    
> > >>>>>>>>>>>finally after doing the refurbishment step by step. 
> This is an    
> > >>>>>>>>>>>incredible machine, one of the best ever made and 
> definately Korg's    
> > >>>>>>>>>>>best Polysynth.   
> > >>>>>>>>>>>  
> > >>>>>>>>>>>Let us know how you proceed, also if you can take some 
> pictues of the    
> > >>>>>>>>>>>board it would help. 
> > >>>>>>>>>>>  
> > >>>>>>>>>>>  
> > >>>>>>>>>>>--- In PolySix@yahoogroups.com, "stagerhodes" 
> <stagerhodes@y...> wrote: 
> > >>>>>>>>>>>  
> > >>>>>>>>>>>>Oh, i'm very pleased regarding this group , many 
> thanks for your   
> > >>>>>>>>>>>>reply and the schematics beeing available for 
> download...  i will   
> > >>>>>>>>>>>>unmount the Trident may be tonight or tomorrow night 
> and will post my   
> > >>>>>>>>>>>>sights inside. This is one of my favorite (regarding 
> it's wood design   
> > >>>>>>>>>>>>and the sound, particularly the synth section) 
> keyboards from korg ,   
> > >>>>>>>>>>>>and i can say i tried almost them all at the time 
they 
> were beeing   
> > >>>>>>>>>>>>produced since i was working demoing them in a shop. 
> So now is the   
> > >>>>>>>>>>>>time for me to have some of them in full working 
> condiction...  
> > >>>>>>>>>>>>Art 
> > >>>>>>>>>>>>  
> > >>>>>>>>>>>>  
> > >>>>>>>>>>>>--- In PolySix@yahoogroups.com, "gil_we" 
<gil_we@y...> 
> wrote: 
> > >>>>>>>>>>>>  
> > >>>>>>>>>>>>>I didn't fully understand how the synth section acts 
> on this machine...  
> > >>>>>>>>>>>>>Also, is there corrosion (green colored) on the 
> battery and near it ?  
> > >>>>>>>>>>>>>Are there bad (black colored)traces ? are the signal 
> and synth boards   
> > >>>>>>>>>>>>>correded as well on some areas ?  
> > >>>>>>>>>>>>>  
> > >>>>>>>>>>>>>Take extra care not to hurt anyting that works. 
> Particually, stay   
> > >>>>>>>>>>>>>away from the 10 leg transistor type component at 
the 
> bottom left   
> > >>>>>>>>>>>>>side of right bottom (signal) board. This one is 
> extremely sensitive   
> > >>>>>>>>>>>>>to extreme temperature changes and is very rare and 
> expensive to get.  
> > >>>>>>>>>>>>>  
> > >>>>>>>>>>>>>You can use the schematics I uploaded to the Files 
> section. 
> > >>>>>>>>>>>>>  
> > >>>>>>>>>>>>>  
> > >>>>>>>>>>>>>--- In PolySix@yahoogroups.com, "stagerhodes" 
> <stagerhodes@y...> wrote: 
> > >>>>>>>>>>>>>  
> > >>>>>>>>>>>>>>Hi,  
> > >>>>>>>>>>>>>>i just bought a Trident MK I in which the poly 
synth 
> section is   
> > >>>>>>>>>>>>>>malfunctioning, i am almost certain that the 
problem 
> is the battery   
> > >>>>>>>>>>>>>>question , and the leakage from it. It seems the 
> tune is ok, all notes   
> > >>>>>>>>>>>>>>are sounding (brass and strings sections), in the 
> synth section one can   
> > >>>>>>>>>>>>>>ear some sound (it is possible to ear the notes 
> pitch, but with some   
> > >>>>>>>>>>>>>>strange effects in them) and the memory section is 
> not working which   
> > >>>>>>>>>>>>>>leads me to the battery question. Is there any 
> special care i must have   
> > >>>>>>>>>>>>>>in this model ?  
> > >>>>>>>>>>>>>>regards  
> > >>>>>>>>>>>>>>Art  
> > >>>>>>>>>>>>>>Portugal 
> > >>>>>>>>>>>>>> 
> > >>>>>>>>>>>>> 
> > >>>>>>>>>>>> 
> > >>>>>>>>>>>  
> > >>>>>>>>>> 
> > >>>>>>>>>  
> > >>>>>>>> 
> > >>>>>>>  
> > >>>>>> 
> > >>>>>>  
> > >>>>>>  
> > >>>>>>PolySix "Digiest" Page: 
http://www.acc.umu.se/~amber/Poly6   
> > >>>>>>Yahoo! Groups Links  
> > >>>>>>  
> > >>>>>>  
> > >>>>>  
> > >>>>   
> > >>>  
> > >>  
> > >  
> > >  
> > > PolySix "Digiest" Page: http://www.acc.umu.se/~amber/Poly6  
> > > Yahoo! Groups Links 
> > >  
> > >  
> > >  
> > >   
> > > 
> >
>