Discussion about the Korg PolySix synthesizer

Try to check 4xxx circuits on effects board... also very popular
problem in korgs is that lm13600 got broken often. ne5517n is cheap
and good replacement for those!  :)



--- In PolySix@yahoogroups.com, "Dr Funk" <frank@...> wrote:
>
> Hi Andy
> 
> 
> > No problem, we are always here to help, if we can! 
> 
> 
> Much appreciated!
> 
> 
> Actually, I do 
> > mean what I say. Look at the circuit diagram and carefully study IC29 
> > and IC34. You will see that pin 5 is connected to the ports on the 
> > CPU. It doesn't look like it on initial inspection, but it is true. 
> > Without these present no data for the effects panel will be clocked 
> > through.
> 
> 
> These both appear to be fine.
> 
> 
> > 
> > What I would suggest is that you print out the KLM-367 circuit 
> > diagram, take out a coloured marker and check the continuity around 
> > both these ICs. As you do mark the line as checked in hideous yellow 
> > ink. Apologies if this is 'grandmother' and 'eggs'!
> 
> 
> No problem!  I am an 'enthusiastic amateur' when it comes to
> electronics, but I've learned a lot in the past few months!  It's very
> satisfying to begin to understand how my synths work.  Anyway, I've
> checked continuity as much as I can, and everything seems to check
> out.  I've checked IC29 and IC34 to the CPU and external connectors,
> and it all seems to be ok.
> 
> 
> > 
> > You can check the logic levels with the oscilloscpe. Sorry I didn't 
> > realize you had one! You could use the DVM to do this but you 
> > wouldn't be able to see a pulse train (rapid changing levels) using 
> > one.
> 
> 
> Sounds good, but I'm not sure where to probe!  IC29 and IC34?
> 
> 
> > 
> > Also you might want to fully test the continutiy of tracks D02 and 
> > P11, P12, P13. These actually leave the 367 and are wired to the 
> > switch via diodes.
> 
> 
> These seem to be ok too.
> 
> 
>  Sorry, it is labourious work, but one you spot the 
> > fault it is a joy to behold!
> 
> 
> I can't wait! :-)
> 
> 
> > 
> > Question? Does the EG Mode and Sub Osc switch do anything?
> 
> 
> Yes, both seem to be working properly.  Also, if effect intensity is
> turned up full, when chorus is selected the filter seems to open up
> slightly, and if phaser is selected there's a low level repeating
> pulse sound audible.
> 
> Cheers
> Frank
>