Modulation wheels, pitch bend wheels, or joysticks have been a common on synthesizers and electronic keyboards since the early days of Moog and
What is not very common is a stand alone unit that is just a joystick
controller or mod wheel set. This is
exactly what the Catstick from Octave Plateau is. Produced in 1981, this device was intended to
be used with the Cat synthesizer (which did not have a modulation wheel or
joystick). It can be also used with any
analog synth or device that uses control voltages.
One of the most surprising things about the Catstick is its construction - it looks like molded plastic but is very rugged and strong - made of metal. A huge advantage of the Catstick is its configurability. The joystick is spring loaded and will always move back to the center. Each direction has its own voltage amount, and VCA amount. Through the VCA, you can select between an external signal (and there are 4 external signal inputs, one for each direction of the joystick), LFO1, or LFO2.
A typical use for this would be to send the output to an oscillator, use left and right (+x, -x) to control or bend the pitch, and up and down (+y, -y ) to add an LFO or vibrato to the pitch. Each direction can have its own output though, so you can also configure something like: +x increases the pitch and adds vibrato, -x opens the filter, +y, mixes in an octave higher, and –y to change the delay time.
Since each VCA has its own input and output, you can also tie all the external inputs together through a multiple and all of the outputs to a speaker and have a quadraphonic panner. The only drawback to this is when the joystick is back to center (and remember that it is spring loaded to default to this position when you are not touching it) then all sound is off. Through a series of additional VCA’s and inverters, one could overcome this shortcoming and actually have the center output to all speakers instead.