Archive of the former Yahoo!Groups mailing list: Discussion about the Korg PolySix synthesizer

previous by date index next by date
previous in topic topic list  

Subject: Re: MG wheel intensity mod

From: "chipaudette" <chipaudette@yahoo.com>
Date: 2013-05-19

Unless you post more detail about the approach from the people on the other forum, I fail to see how a 220K pot in parallel to the existing mod wheel will do too much.

If you instead wired a 5K or 10K pot as a variable resistor and installed it in parallel to the existing pot, there would probably be some low settings on the new pot that would indeed reduce the amplitude of the LFO enough that the mod wheel would feel less sensitive. A 220K pot (even a 220K log pot) would have to be turned WAY WAY down to get this effect. My proposed approach in my initial reply is far more effective and controllable than this method, though.

My proposed approach cuts down the amplitude of the LFO signal before it gets to the Mod wheel. Alternatively, you could cut down the LFO signal coming out of the mod wheel. In this case, you'd attach the wiper of the Mod wheel to the top of your new pot. The bottom of your new pot would go to ground. The wiper of the new pot would get connected to the wire that used to come from the wiper of the Mod wheel.

Again, without more info from what the other folks suggested, I'm not really seeing how it'll achieve what you're looking for.

Chip



--- In PolySix@yahoogroups.com, "theofielb" <theofielb@...> wrote:
>
> Well, since that is a completely other method as the one I was thinking of I would use a different pot indeed. I don't know if this method works actually, since people on another forum preferred a completely differend method: A potmeter parallel to the mod wheel, connected to GND and LFO.
>
> --- In PolySix@yahoogroups.com, "chipaudette" <chipaudette@> wrote:
> >
> >
> > Looking for the Mod wheel on the schematic, I find it at the bottom-center of the page for the KLM-369, 370, and 371 boards. I see that the mod wheel is configured to directly attenuate the LFO signal prior to mixing in with the Bend signal. Based on this configuration it appears likely that the LFO signal is ground-referenced, meaning that the LFO signal swings both positive and negative. This is good.
> >
> > To adjust the intensity, you can either add a pot to make the intensity adjustable, or you can just add a resistor de-sensitize your wheel by a fixed amount.
> >
> > In either case, you'd disconnect the wire going to the top of the pot. For the fixed resistor, simply solder in the resistor between the wire and the pot. If you use a 10K resistor, you'll halve the intensity of the mod wheel. Easy.
> >
> > For the potentiometer, connect the wire to the top of the pot. Connect the bottom of the pot to ground. Connect the wiper of the pot to the top of the Mod Wheel pot. That's not too bad, either.
> >
> > If you use a pot, be careful about the value of the pot that you choose. I think that 220K is much too big. The total series resistance of the LFO/MOD path matters because of how its signal is passively mixed in with the signal for the bend wheel. I'm not sure what'll happen if, by adding the 220K pot, you add tons of series resistance. Maybe nothing will happen, maybe something weird will happen.
> >
> > Personally, I'd simply use a 10K pot. And, since it's basically being used as a pitch control and not a volume control, I'd chose a linear pot over a log pot.
> >
> > Good luck!
> >
> > Chip
> >
> >
> >
> > --- In PolySix@yahoogroups.com, "theofielb" <theofielb@> wrote:
> > >
> > > Hi there,
> > >
> > > I want to mod my P6 slightly by adding an intensity control for the modwheel, it is a little too much for my taste sometimes... I know I have to hook up a parallel potmeter, I will use a 220K log I think, but how do I have to hook it up? The modulation pot controls LFO and MOD, but I don't understand how...
> > >
> >
>