Zachary Vex has been building unusual guitar effect pedals for 21 years, but he debuted what might be his strangest yet: a vibrato/phaser run entirely by a candle. Because it's a custom piece created by hand in a machine shop, one Z.VEX Candela Vibrophase will run you about $US6000 ($8328), or at least that's what Vex estimates. Vex recently announced his latest creation at this year's National Association of Music Merchants convention (NAMM). It's beautiful, inspired, totally impractical for almost any gigging musician and possibly a small "up yours" to the cost of nine-volt batteries. But how does it work? Bear with me here.
The Candela Vibrophase looks like a Rube Goldberg machine, but at its heart is a a highly efficient but low-power Stirling engine, a design that was invented (and fell into obscurity) about 200 years ago. The heat from the candle provides a temperature differential to drive the engine's tiny piston which powers a flywheel. The flywheel spins an optical disc with an offset opaque coating. On one side of the disc is a bank of photo cells, while on the other side is, once again, the candle. This intermittent input to the photo cells provides the tremolo sound.
Make sense? If not, a good analogue might be the ridiculous sound your voice makes when you talk into a moving fan.
The photo cells are powered by solar cells on the opposite side of the candle, and also come equipped with an adjustable filter to increase or decrease the amount of light getting through -- which acts similarly to the dry/wet knob on other effects. Likewise the intensity of the effect can be changed by moving the Candela's neodynium magnet closer or further from the flywheel.
So what would you even do with something like this?
"Someone would buy it because they want to have it in the their man cave basement studio," Vex told YouTuber The Tone King, "When you're trying to create music, having stuff that inspires you... helps you think more clearly and helps you be more creative."
Maybe so, but for what a high-end audio habit costs, most musicians should stick with drugs.