Here's what Fulltone say about the Clyde Standard Wah:
Clyde McCoy was a big-band Trumpet Player in the '60s... not a great musician, but one famous for getting a muted "wah wah" sound. This led to Vox trying to approximate this muted trumpet sound in a pedal... hence the Vox "Clyde McCoy" wah wah circa 1967.
Jimi Hendrix and Eric Clapton both used a Vox "Clyde McCoy" model wah wah. Photos taken during the recording of "Electric Ladyland" document Jimi's as being the "signature" model, featuring Clyde McCoy's name written out script style on the bottomplate. The other type of Clyde McCoy was the "picture" version, which had Clyde's photo on the bottomplate. The "signature" model, with it's great sounding "halo" inductor, is what the Fulltone CLYDE is modeled after.
The Fulltone "CLYDE" was born from taking the best of the best of my more than 25 pc. vintage Vox wah collection, and analyzing every aspect... going so far as sacrificing a few of the vintage inductors to get it right.
Our Inductor is a tuned core hand-made unit using EXACTLY the same type wire and inductance as the '60's era Vox, except VERY consistent from one unit to the next. A tuned core inductor is much more expensive to make, but the end result is worth it. The only change from the original '60's Vox design is the addition of a very usable internal "Resonance Control" which is a large durable trimmer, for bass and gain adjustment, which is easily adjustable by hand without tools and with room to mark your favorite settings.