i need midification info for poly 800

F

fishi

Guest
I'm in a desperate need for a filter and cutoff modification on my Korg Poly 800. I want to put some knobs for realtime control.
I couldn't find any more detailed info on how to perform such a surgery.
If anyone has any ideas wher to find it, or maybe he has done this himself, please tell me!!!

thanx a lot!!:D
 
yeah I think your best option would be to buy one of those little Moog Filters they have, you might want to get the ring modulator too. I have played with the Poly 800, they are great there sound is so warm and you can get them so cheap. They definetly need a filter though, and maybe a few effex. Good luck, and let us know what you ended up doing to it or with it.


For those of you that don't know of this synth should check one out, they can be found super cheap and sound great. From what I am told they are analog which would explain the natural warm sound they seem to get.

Taos
www.djtaos.cjb.net
 
Of course it would be the best way to have a controler, but this is an early midi era synth and it doesn't recieve SYS-EX. Just on off. So goodbye to controler.

The filter would be a good idea, but I LIKE the original filter which gives this little synth its sparkle.
Yeah, it's analog/digital hybrid. It has 2 DCO's (digitally controled oscilators), and also digitale envelope generators, but other stuff is voltage controled like on classic analog synths. And yeah, it does sound very warm.....and verrrrry 80's if you want it to.

And I have also found out how to modify it so i'll probably do it this weekend.:D
 
Liet said:
cool, but the poly 800 does recieve standard controller data, right? So there should be no problem with a controller.... :confused:

no, I'm afraid not. I think only the second version mkII supports that. The filter doesn't respond to midi sysex.
as I said it has a really poor midi implementation. it acts ok as a midi keyboard and maybe a controler with that funny joystick, but nothing more.
yeah, I was a bit disapointed with that, but i'll modify it and it will kick ***!!!!

TAOS: i think i'll modify it this weekend. i'll report how did it work.
the only thing i'm afraid of is that i can screw all the patches up if not turning the pots inside correctly. oh well. a little sacrifice has to be done, i guess.

but, hey Chriss! you being into trance; you should check this little plastic buddy out. it can produce wonderfull trance stuff. it has really strong LFO which can act like an arpeggiator whan you play some riffs on top of a sequence. really unique!!!!!! i started jumping allover my room when that happened:victory:

and I got it for $40 with original powersuply and original manual. and it belonged to Umek once.
 
No-one has yet pointed out that this is a digital instrument. There isn't any pots inside. It's all numbers in microchips.

I recently built a digitally controlled multi-mode audio filter with user memories etc - so im speaking from experience...

In order to make a real-time controller for cutoff, you'd first need to identify what the binary range of the filter control is, the address (if thats how its arranged), or the particular pin on a particular microchip you'd need to apply this binary number too. You'd need a rotary encoder (expensive) which sends out a digital square wave (like an alpha dial on a sampler). This would trigger a simple counting circuit to output its binary number to adjust the cutoff. Any such modification is extremely hard with a digital instrument....impossible for anyone without in-depth knowledge of the synth architecture and good education in digital electronic systems.

Sorry. :(
 
ukcoolat!
I gues you're a real expert on this so I wont try to opose you. BUT! many people has done this modification.
I don't know if pots belong to digital synths or to analog synths (i don't even know what are they and how they look like), but everyone that has done this surgery is talking about TRIM POTS for cutoff and reso. they say you have to remove something from them and replace it with 100k audio tapper = knob, drill a hole in the front pannel, put the knobs in and voila.:)

hey, if you're good at this, and have lots of knowlege, please explain this stuff to me, because I know absolutelly nothing about this stuff.
I would have it modyfied by a professional, anyway.

thanx.:D
 
AHHH right I understand what your getting at now.

A POT is a POTENTIOMETER. Its basically an analog device with a knob or someway of varying its resistance. A TRIM POT is a tiny little one mounted on the circuit board, and from what you say, it sounds like there must be some inside there for calibration (since they can't move everytime a memory location is recalled because they're mechanical - they're probably set once at the factory and left).

But yea - get someone who's done it before to do it. And if i ever pick up a POLY 800 i'll dive in and take a look at it. :)
 
thanx man.
and they say if you twist the pot too much, you can really hurt your speakers with resonance. huh, i better be carefull...
so, did I understand you right?
the pots are set in the factory and stay in that position forever, right? unles you open the box and twist them yourself?
 
yea thats right from what im understanding - i can't see any other reason why there'd be pots inside a digital instrument - (unless you have your info distorted). :)
 
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