Spinner

Features:

• Two-band rotary chorus.
• Full complement of controls for both frequency bands.

Theory of operation

There are two rotating sound sources - one for frequencies above the crossover point and one for frequencies below the crossover point. Each so-called "rotor" has two speeds which are individually adjustable. Speed is specified in RPMs on the GUI. In addition the Acceleration from Slow to Fast is programmable as well as the deceleration from Fast to Slow.

Each frequency band has a nominal "center" signal and left/right "side" signals.

The center signal has two AM components: panning left/right and tremolo'd (apparent forward/back motion) - each one is independently adjustable for both speeds and both frequency bands. In addition, there is a center FM component that is based on the position of the rotor *independent* of the current AM levels. As with the AM parameters, the FM level is independently adjustable for both speeds. The FM Chorus Depth is adjustable per frequency band (but not per speed)

The side signals comprise a more-or-less classic stereo chorus - the degree of stereo separation is controlled by the "SideImage" control. The Center/Side control allows the user to vary the mix of these two basic components. The FM level shares the same setting as the center signal.

As with the center signal, the FM Chorus Depth for the side signal is adjustable per frequency band.