for music synthesizers.
The Joystick controller uses two D.C. mixer pcbs, one per axis, each mixing a front panel controlled D.C. offset and the voltage out of the joystick. The "master gain" control of the mixer is used to control the range of the output.
The above circuit is simply repeated for the second axis.
The resistor marked XXk can be matched to the resistance of the pot in the joystick itself. The value is not critical. Some joysticks do not use the full travel of their pots, so it may be necessary to place trim pots above and below the joystick pot to allow correct adjustment of the 0 volt and maximum positions. In such a case, the lower trimpot would need to go to the negative rail instead of 0 volts. Alternately, another trimpot could wired in a similar fashion to the panel mounted offset pot using another input of the mixer, to allow for zeroing.
Article, art & design copyright 1999 by Ken Stone