Synth-DIY Yahoo! Groups Archives

Just joined, Have a MkII with a strange pitch problem...

2013-12-08 by william greig

Hi, glad to find this group! I got a second hand Korg poly 800 MkII that had a dead battery which I've fixed up, now that I can make a patch and save it on it, I've discovered something else.

The problem is when you apply pressure to the whole case, either by twisting it or pushing on the keys harder than normal, the whole pitch of the keyboard changes! I have no idea why! It can go out by over a semitone, so the tuning slider doesn't solve it. This makes it unable to play with other instruments.

Would anyone have ANY clue why this would happen? I'm up for poking around in side if I need to. Also looks like someone has trying to install their own audio jack on the opposite ends from the rest to make using it as a keytar easier, but I'm pretty sure its not wired up.

I'm going on holiday tomorrow for a week so might not be the fastest at replying or getting photos if anyone wanted.

I would love to mod this if I can solve this problem!

Thanks!

RE: Just joined, Have a MkII with a strange pitch problem...

2013-12-17 by <pan.ryba@...>

There is a tuning Variable resistor inside - VR1
http://www.memi.com/makers/hwsw/basteln/poly800_mod.html
controling whole pitch of poly800
maybee this causes the problem?
but be careful because when you set it too low, it resets whole poly 800 and erases all of your presets.

Re: [korgpolyex] RE: Just joined, Have a MkII with a strange pitch problem...

2013-12-18 by william greig

Thank you I will have a look inside! Its ok I only have one half done patch anyway. Thanks for your reply!

On Tue, Dec 17, 2013 at 2:55 AM, <pan.ryba@...> wrote:

There is a tuning Variable resistor inside - VR1
http://www.memi.com/makers/hwsw/basteln/poly800_mod.html
controling whole pitch of poly800
maybee this causes the problem?
but be careful because when you set it too low, it resets whole poly 800 and erases all of your presets.

Re: [korgpolyex] OT My new electronic music project

2013-12-20 by Daniel Forró

Sorry for shameless self promotion, but I started to work on the new music project. My EX800 (and other Korgs) are there, too. Here are the first three CD finished. Check or buy if you find it interesting:

http://www.bodymusictherapy.com

Vol. 1 – Music for the Heart

http://www.youtube.com/watch?v=TaNMtDdbadM

Vol. 2 - Music for the Brain

http://www.youtube.com/watch?v=0SmlR_c3l20

Vol. 3 – Music for the Lungs

http://www.youtube.com/watch?v=KtraNXE1USY

All the best! Happy holidays!

Daniel Forro

www.soundclick.com/forrotronics

www.danielforro.com

Re: [korgpolyex] OT My new electronic music project

2013-12-23 by Michael Hawkins

Nice work. Where is the Poly-800 in these albums?

Mike

On Friday, December 20, 2013 10:46 AM, Daniel Forró <dan.for@...> wrote:

Sorry for shameless self promotion, but I started to work on the new music project. My EX800 (and other Korgs) are there, too. Here are the first three CD finished. Check or buy if you find it interesting:

http://www.bodymusictherapy.com

Vol. 1 – Music for the Heart

http://www.youtube.com/watch?v=TaNMtDdbadM

Vol. 2 - Music for the Brain

http://www.youtube.com/watch?v=0SmlR_c3l20

Vol. 3 – Music for the Lungs

http://www.youtube.com/watch?v=KtraNXE1USY

All the best! Happy holidays!

Daniel Forro

www.soundclick.com/forrotronics

www.danielforro.com

Re: [korgpolyex] RE: Just joined, Have a MkII with a strange pitch problem...

2014-04-10 by william greig

THE PROBLEM: When I apply pressure to the lower right corner on the case right beside the highest note the whole synth pitches up, up to a whole semitone pretty much. I can't figure out whats causing this and it makes it unusable because if you press the keys to hard it shifts pitch, or if you use it with a strap it moves around and that causes it to happen.

UPDATE: Just tried adjusting VR1 and seeing if anything is pushing on it and it doesnt seem to be. I got it in tune but the problem makes it go out of tune. And it keeps it out of tune where it left if you turn it off then on again, so it wont reset back to normal pitch. If you pull the case up instead of pushing down it can make the pith go down a bit too. Could something attached to the case like the tuning pot be at fault? Im pretty sure its not the joystick playing up either.

Any help is HUGELY appreciated.

If I cant fix this do you think someone more experienced with synths or electronics could for me?

Thanks!

On Wed, Dec 18, 2013 at 5:00 PM, william greig <wilzgreig@...> wrote:

Thank you I will have a look inside! Its ok I only have one half done patch anyway. Thanks for your reply!

On Tue, Dec 17, 2013 at 2:55 AM, <pan.ryba@...> wrote:

There is a tuning Variable resistor inside - VR1
http://www.memi.com/makers/hwsw/basteln/poly800_mod.html
controling whole pitch of poly800
maybee this causes the problem?
but be careful because when you set it too low, it resets whole poly 800 and erases all of your presets.

Re: [korgpolyex] RE: Just joined, Have a MkII with a strange pitch problem...

2014-04-10 by william greig

Ok ,so If I turn it off and unplug it for a few mins it seems to reset to proper tuning. But that could just be because of certain movements. If I have the case apart and try twist each side separately it doesnt seem to have a problem, its just when I sit them back in place exactly that it does this.

On Thu, Apr 10, 2014 at 2:17 PM, william greig <wilzgreig@...> wrote:

THE PROBLEM: When I apply pressure to the lower right corner on the case right beside the highest note the whole synth pitches up, up to a whole semitone pretty much. I can't figure out whats causing this and it makes it unusable because if you press the keys to hard it shifts pitch, or if you use it with a strap it moves around and that causes it to happen.

UPDATE: Just tried adjusting VR1 and seeing if anything is pushing on it and it doesnt seem to be. I got it in tune but the problem makes it go out of tune. And it keeps it out of tune where it left if you turn it off then on again, so it wont reset back to normal pitch. If you pull the case up instead of pushing down it can make the pith go down a bit too. Could something attached to the case like the tuning pot be at fault? Im pretty sure its not the joystick playing up either.

Any help is HUGELY appreciated.

If I cant fix this do you think someone more experienced with synths or electronics could for me?

Thanks!

On Wed, Dec 18, 2013 at 5:00 PM, william greig <wilzgreig@...> wrote:

Thank you I will have a look inside! Its ok I only have one half done patch anyway. Thanks for your reply!

On Tue, Dec 17, 2013 at 2:55 AM, <pan.ryba@...> wrote:

There is a tuning Variable resistor inside - VR1
http://www.memi.com/makers/hwsw/basteln/poly800_mod.html
controling whole pitch of poly800
maybee this causes the problem?
but be careful because when you set it too low, it resets whole poly 800 and erases all of your presets.