[sdiy] XY controller build?

[Dave Manley]

On 1/6/2016 10:08 AM, Terry wrote:
> Hi All,
>   I made a complete scratch build of a Moog 959 X/Y controller. There is no real circuitry other than a limiting resistor to the 959 and it used audio taper AB type J 10K pots. Had to be carefull
> setting it up, as the pot travel was about 30 or so degrees and had to be setup with zero volts at the center of the stick. Otherwise the full voltage at either end CW or CWW was enough to short out
> your power supply so care is needed setting up.
>   The advantage of the Bob Moog design was direct connection to high quality pots with no backlash. The AB type J pots had a rotational resistance that was the action of the stick. Cheap pots will
> give less than perfect action, but with those old AB type J pots the action was excellent.
>   The other advantage was the parts required were all easy to fabricate and the one L bracket to connect both pots was the real design advantage over the typical consumer joystick.
>   I wrote out my project on the Moog website. Hopefully the photos show as on some browsers they do not. But should give some ideas for a scratch build X/Y controller.
> Link here:
> http://forum.moogmusic.com/viewtopic.php?f=1&t=21438&p=129221&hilit=959+x#p129221

Hi Terry,

I was going to ask why audio taper, but from the link I see the first pic
is a single quadrant X/Y controller so audio taper would work.  Never saw
that before - but why not?

For a 4-quadrant version I think linear would be required. (Must
admit TLDR the entire link.)

-Dave