Based on the Demeter Tremulator, favoured by Jonny Greenwood and Eric Clapton for its tweed-like shimmer, Valeton's Wave Shaker doesn't offer a whole load of versatility, but makes up for it with a warm vintage throb.
While the bias knob shifts the sound slightly further towards square wave, it acts more like a second depth control for the pedal's triangle-wave wobble.
Still, the speed dial goes from gentle waves to rapid-fire stutters, while the vitally important volume control makes up for any perceived volume drop - brilliant!