I'd consider the usable range from 0 to about 9 1/4

The dial adjustment really does have a nice range and you can hear the difference unlike some other pedals where there is not any significant difference until the last 1/4 movement of the dial

Through only three controls (on/off, tone, and rate), this little wonder produces an almost unlimited range of phasing effects, from very subtle to outrageous.

The phaser has a "tone" switch that switches it from negative feedback to positive feedback, and the range available in each mode is set.

I find that though a depth knob would be nice, the preset range is very usable - the positive setting is more warbly and the negative setting is more vertigo inducing.

Good phaser pedal, a little bit of a volume drop, but good sound and nice range

Your street cred as a player will suffer a