Discussion about the Korg PolySix synthesizer

Hi gil and others,

no unfortunately not. I'm quite busy so I didn't find time for further
experiments. I got some great hints from German synthesizer gurus, though.

One of those hints said: The 4066 chips go bad whenever the voltage on
their input comes close to their supply voltage. So if you're messing
with those, put them on a socked and be sure to have replacements
available...

And some other hints, now I hope to find the time soon.

Still I'm wonderhing whether I will sell the Trident MK2 or not once I
got it fixed. I'm not a collector, I'm trying to be a musician.

Best,

   Niels


gil_we schrieb:
> Hey, any news ?
> 
> 
> 
> 
> --- In PolySix@yahoogroups.com, Niels Ott <niels.ott@...> wrote:
>> Hi gil,
>>
>> the SSM* are OK, I checked them. I had a nice day with the 
> oscilloscope
>> and found out: The output of the signal generator board is already 
> bad.
>> Then I replaced two opamps 4558 which I suspected to be the problem 
> but
>> it didn't help. Still 0V out instead if the signal on oszillator 2 
> (VCO
>> 1 (sic)).
>>
>> Next suspect was the CMOS switch which I replaced by a similar 
> type. But
>> Somehow it wasn't similar enough, so I got -9V in the output now, 
> which
>> is definitely not good.
>>
>> I'll keep on soldering. ;-)
>>
>> Best,
>>
>>    Niels
>>
>>
>> gil_we schrieb:
>>> Did you switch SSM2056 and SSM2044 between voices to see if it 
> may 
>>> lay there ?
>>>
>>>
>>> --- In PolySix@yahoogroups.com, Niels Ott <niels.ott@> wrote:
>>>> Hello there,
>>>>
>>>> my Trident MK2 is defective.
>>>>
>>>> Symptom: VCO 1 is defective for one voice.
>>>>
>>>> Up to now I was able to found out: Input 1 of IC704 (4x CMOS 
>>> switch) on
>>>> KLM-379 doesn't get the VCO signal on voice 7. On all others it 
>>> does.
>>>> There are some oddities with op amp IC707 but I'm not yet sure. 
> The
>>>> schematics and the circuit board design hint to the direction 
> that 
>>> IC707
>>>> "feeds" IC704.
>>>>
>>>> The IC707 is a 4558, I assume that it is similar in the Polysix.
>>>>
>>>> Did anybody of you experience a similar problem? What about 
>>> replacing
>>>> the 4558, did this help?
>>>>
>>>> Furthermore, some of the 4558s carry a date stamp of 1997 which 
>>> means
>>>> they must have been replaced by an earlier owner.
>>>>
>>>> Unfortunately there is no shop selling electronic parts in reach 
> so 
>>> I
>>>> can't just go for it and try replacing it. Mail order is an 
> option 
>>> but
>>>> not for a few ICs...
>>>>
>>>> Thank you for commenting.
>>>>
>>>> Best,
>>>>
>>>>   Niels
>>>>
>>>
>>>
>>>
>>>
>>> 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
> 
> 
> 
>