The idea was to generate random sequences by turning a knob. When you turn the LCK knob, a voltage between roughly +9V and -9V is passed to a shift register with an R2R digital-to-analogue converter, which stores the voltages from the pot with each clock signal. Depending on how the control is turned (range and speed), different voltages are sampled, resulting in a different CV and gate sequence. The SER input allows the use of external voltages which are passed to the shift register (mixed with the voltages from the potentiometer). The switch enables or disables the external voltage from the SER input.

To use it, simply connect a clock signal to the CLK input. HAPHA will then produce a random GATE signal at the upper output socket and a random CV signal at the lower output socket. You can create and lock a new sequence of voltages and gates by adjusting the LCK knob, and an LED indicator will show when a voltage change occurs.

For additional control, if you move the SER switch to the right, you can patch an external voltage (audio or CV) into the serial input SER which will directly influence the random voltages at the outputs. With an external voltage patched, you can still change the sequence by turing the LCK pot.