It has its ups and downs 

Anasounds define tremolo as "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."
TonePedia defines tremolo as "That lovely warming movement heard in many songs and you never even knew it was there"

Tremolo is one of those effects most players feel they can live without ... until they try it. Anasounds have worked hard to maintain your original signal, using no digital witchcraft in the signal chain but there is some digital magic in the controls. This allows for some cool tricks including tap tempo, subdivisions, kill dry, self-oscillation by holding down the tap footswitch, and most innovative of all .. you can easily update this analog pedal with new and improved chips Anasounds will offer along the road. 
Use the Anasounds Optical Tremolo with the spinner expression pedal to get effects never before possible!

Try this alongside the Ages harmonic tremolo from Anasounds and many others on TonePedia