V847 Wah

The V847 is Vox's reissue of the legendary wah-wah pedal invented in 1966 at Thomas Organ Company. The circuit uses two cascaded transistor stages with a resonant LC filter whose frequency is swept by the treadle.

The inductor and capacitor create a resonant peak centered around 750Hz (mid position) that sweeps from 450Hz to 1.6kHz. Selected frequencies are amplified up to 18dB while surrounding frequencies are attenuated.

The minimal component count keeps power consumption below 1mA. The simple single-layer PCB design with insertion components has proven reliable over decades. True to the original circuit that defined the wah-wah effect used by Hendrix and countless others.