Korg Poly800/EX800 Users

I've been fiddling around with crossing the wires from the 1b connector that went to the 
missing joystick board and have managed to thoroughly confuse myself.  There's some 
crazy digital latching with the pitch control going on that I wasn't expecting to find, and 
most definitely don't understand...

If I apply an instantaneous (touch and remove) +5 volts to 1-4A the machine latches down 
a fifth, if I apply -5V OR ground, it latches up a fifth. Anyway:

A couple of questions, if somebody would be so kind as to answer:

1) What is the original behaviour of the joystick?  What is the pitch bend range and how 
does the vcf/dco joystick axis interact with the patch parameters?

2) I see the KLM-599 Joystick board on the schematics, but, where are the variable 
resistors that represent the stick axes?

3) Can anybody out there make sense of what the components on the joystick board 
schematics do?

Thanks,
-Tim  

--- In korgpolyex@yahoogroups.com, Michael Hawkins <korgpolyex800@...> wrote:
>
> Hi Tim,
> 
> let's try this.
> 
> Connect the -5V side of the pots to ground.
> 
> Mike.
> 
> 
> 
> ________________________________
> From: serotonic_sound <sero-tonic@...>
> To: korgpolyex@yahoogroups.com
> Sent: Monday, February 16, 2009 11:02:30 PM
> Subject: [korgpolyex] Re: Missing Joystick board (KLM-599) "mod"
> 
> 
> Actually, I wasn't quite right in my description.  The vcf isn't affected at all by the mod 
> pot.
> 
> -Tim
> 
> --- In korgpolyex@yahoogro ups.com, "serotonic_sound" <sero-tonic@ ...> wrote:
> >
> > Hey Mike,
> > 
> > Thanks for your help...I did what you recommended. ..I'm not sure what you were 
> > expecting the results to be but I'm getting the following:
> > 
> > 1) The pitch pot only works the first half of its range.  From Full Left To Center 
increases 
> > the pitch from about a 5th down to normal.  But, the second half (Center to Right) 
does 
> > nothing.  I would have expected the pitch to rise above normal.
> > 
> > 2) The Mod pot also only does something through the first half of its range...I don't 
> know 
> > exactly what the behaviour of the joystick was originally, but I find that with the DCO 
> > amplitude mod parameter set to 0 I can mod the dco mod go to 15 with the pot. (Its at 
> 15 
> > when the pot is in the middle).  With DCO set to zero the pot does nothing to the 
DCO. 
> > With the vcf mod parameter set to zero the pot does nothing to the vcf.  With the vcf 
set 
> to 
> > full, the pot increases the vcf from off to full.
> > 
> > I used all the wires from the existing 1b connector and tapped -5 (blue) to one side of 
> the 
> > pots, +5 (red) to the other side of the pots.  Then attached one middle post to 1-4B 
and 
> > the other middle post to 1-5b...Sound right?
> > 
> > I verified that the pots are sending -5 through +5 volts with zero in the middle 
through 
> > 1-4B and 1-5B.
> > 
> > I can play in tune again, but the results aren't quite what I was expecting...
> > 
> > What do you think?
> > 
> > Thanks again for your help...
> > -Tim
> > 
> > 
> > 
> > --- In korgpolyex@yahoogro ups.com, Michael Hawkins <korgpolyex800@ > wrote:
> > >
> > > If I were in your situation I wouldn't touch the existing trim pots.
> > > 
> > > And, I would use two 10K linear pots or trimpots to fake the missing joystick 
> assembly.
> > > 
> > > Connect the left and the right side of both pots to -5V and +5V.
> > > 
> > > And connect the wipers of each to connect pin 1-4B and 1-5B.
> > > 
> > > This will allow you to set the VCF/DCO modulation to zero as well as pitch bend.
> > > 
> > > If you use pots you could even make a plate to go over the joystick hole and mount 
> the 
> > pots right there.
> > > 
> > > I still think you should pop a new joystick in there though. LOL
> > > 
> > > Mike.
> > > 
> > > 
> > > 
> > > 
> > > ____________ _________ _________ __
> > > From: Gordon J. C. Pearce MM3YEQ <gordon@>
> > > To: korgpolyex@yahoogro ups.com
> > > Sent: Thursday, February 12, 2009 6:44:20 AM
> > > Subject: Re: [korgpolyex] Missing Joystick board (KLM-599) "mod"
> > > 
> > > 
> > > On Thu, 2009-02-12 at 08:44 +0000, serotonic_sound wrote:
> > > 
> > > > Gordon, you said I could potentially wire up a couple of 4.7K resistors... but it 
looks 
> > like 
> > > > that board has a few more components, where would I install these resistors 
> exactly 
> > given 
> > > > that I'm missing the entire joystick assembly and board?
> > > 
> > > I'll dig out the Poly-800 and draw out the circuit of the joystick board
> > > later today.
> > > 
> > > Gordon
> > >
> >
>