To put it in the simplest terms,
tremolo is a cyclical volume variation
from the original volume to a decreased version
(all the way to the extreme version of the effect
which completely cuts the sound in a rhythmic fashion)
following a set tempo.
Up to that point, Anasounds had not come up with a tremolo yet,
since we were waiting to get a design that would justify
bringing a new tremolo into an already saturated market.
Until now, you could get more from your pedals
by adding a tap tempo footswitch or an expression pedal.
Truthfully, what was called an expression pedal
was more of a control pedal that would have the exact same effect
as turning a knob with your foot.
Very handy obviously, but not too creative.
With the introduction of the Spinner,
here comes the first expression pedal worthy of the name.