One guitarist I played with was adamant that mute switches and volume pedals were for the unskilled. He insisted every guitar player should learn how to use their volume knob on the guitar or they shouldn’t be playing. A bold statement from a big dick. For the rest of us pussies, there’s devices like the DOD FX-17 Volume / Wah pedal, manufactured from 1987-2000.
Since the first wah, people have been trying to find new ways to do the same thing. First it was the Crybaby style pinion gear to turn the pot and then a pulley system to get more sweep, but that could always lead to scratchy pots. Morley invented the LDR light-based system with a movable curtain to avoid scratchy pots, but the curtain system took up some room.