Jack Conte put together this very nice demo video for the Electro-Harmonix Riddle, an effects pedal that brings synth-sculpting filtering goodness to the guitar.

Riddle Features:

• 80 Hz to 5 kHz frequency response tailored for guitar
• Optional expression pedal control
• Switch selectable analog distortion designed for guitar
• Start and Stop sweep control
• Low Pass, Band Pass, High Pass filter select
• Start and Stop for filter sweep and Q control
• Separate Dry and Effect outputs
• 9.6VDC 200mA power supply included

via EHX:

The Electro-Harmonix Riddle is a powerful and precise envelope filter fine-tuned for guitar frequency response.

Sculpt your envelope to reveal a truly expressive tone, with a defined and unique signature. Riddle will deliver tight and smooth control over the complete 80 Hz to 5 kHz range, with a consistent and even sweetness

.Need some edge? Engage Riddle’s analog distortion and dial in anything from subtle bite to dominating crush.