JAM is known for their NOS components and obsession for analog circuits, so it's no surprise that when it comes to tremolo they focused on the legendary circuits from early Fender amps. Although Fender marketed this effect as "vibrato" the pulsating volume swell became a stand-out effect in many genres of music. It may be odd to think of a volume swell as having a "tone" but the hallmark quality of those early circuits were their overt warmth and depth in the throb of the signal. Using period-correct components the Chill has achieved this to an impressive degree, all the while offering you precise control.
The layout is rather simple:
Speed - From a lazy carousel to frantic stutter, the Chill can easily transform from ambiance to special effect.
Depth - This controls how deep the volume swells are. At low levels it's like letting your signal sway in the wind and cranked up you get the urgent throb that borders more on effect than enhancement.
Level - Here's a cool trick. If you turn the depth knob all the way off the Chill can make a respectable clean boost. By it's nature there isn't much color and if you need a push in a pinch, it's a fun and easy way to utilize the circuit.
If that's not enough tweak-ability for you check out The Big Chill, which features two speed settings, special Chop effect and 3-position wave selector among other unique characteristics. Overall, the Chill teaches us that tremolo is much more than volume.