It’s a Wah Wah Wah Wah World

I just got a new wah pedal and it’s got me thinking about this effect and my long-standing affection for it.

Why Is a Horn Player's Name on my Pedal?

The wah wah pedal has an interesting history. There is some debate about what qualifies as the very first wah pedal because the concept of a foot-activated tone control was played around with quite a bit. But what we think of now as a "wah pedal" was created by a handful of people associated with Vox/Thomas Organ in the mid '60s and it was something of a happy accident. At the time, Thomas Organ (the US distributor for Vox amplifiers) was creating transistor versions of Vox's tube amps for sale to the US market, in order to meet high demand for Vox amps inspired by the British Invasion, as well as reduce manufacturing costs. As a very minor part of that effort, Brad Plunkett, a junior engineer at Thomas, had been tasked to redesign the midrange boost circuit from the Vox Super Beatle amp to reduce its cost by replacing the original's expensive 3-position frequency switch with a relatively cheap potentiometer. An added advantage of this redesign was the ability to continuously sweep the boost to an exact frequency. Plunkett developed a prototype and was demoing/testing it using an electric guitar with a few other Thomas engineers and artist consultants, including Del Casher, a session guitarist and Vox endorser. Casher liked the way it sounded when the frequency knob was turned and he thought it would work well as a standalone guitar effect. So he suggested installing it into a Vox organ volume pedal so guitarists could sweep the frequency while playing. 

And so the wah pedal was born.

Sometimes products are so good that they defy their manufacturer's best efforts to botch them. The wah pedal was one of those. Before they released it, the pedal was demoed for Joe Banaron, Thomas' CEO. Banaron concluded the effect would be better marketed to horn players (playing through a microphone and amp, obviously). That sounds crazy nowadays, but there was actually some reasonable logic behind that idea. Trumpet and trombone players had been creating "wah wah" sounds for many decades by manually manipulating a mute (including the suction cups from toilet plungers!) over the bell of their instruments. Jazz trumpeter Clyde McCoy had become well-known for this sound from his 1931 recording of Sugar Blues, which became his signature song. And so Vox/Thomas Organ paid McCoy $500 to endorse the pedal, which he had never actually used!

The Vox Clyde McCoy wah pedal was introduced in 1966 and within a year, thanks to being quickly adopted and popularized by Clapton (Tales of Brave Ulysses), Hendrix (The Burning of the Midnight Lamp), and others, Vox realized that the real market for these pedals was guitar players (proving Casher right). So in 1967, they ended the association with McCoy, the pedal was renamed the Vox V846, and its origins as a horn effect were quickly forgotten except among guitar nerds like myself. That same year, Thomas Organ released their own (identical) version of the V846 which they called the Crybaby. Original Vox Clyde McCoy wah pedals with Clyde's likeness or signature on the baseplate command huge prices on the vintage market.

Me and Clyde, We Go Back

My own history with the wah goes back to about 1982 when I bought a Dunlop Crybaby from a fellow teenage guitar nerd. It was only the 2nd effect pedal I had ever purchased. That pedal must have been one of the early Dunlop-made Crybabys, since it was purchased not long after Dunlop acquired the Crybaby brand from Thomas Organ in 1981. In any case, I’ve been a fan of wah pedals ever since.

As an aside, the guy who sold me that pedal, KK Stowe, or Kurt as I knew him, went on to become a well-regarded guitar teacher, instructional book author, and player in Nashville. It was clear Kurt was going to be a pretty special player even back then. And he wasn’t even the best player in my high school! That's not a knock on him. (I certainly wasn't the best player, for the record.) My little school just had an amazing bumper crop of guitarists in the early 80s! But I digress...

Bom Chicka Wah Wah

Although a lot of people consider wah pedals to be cheesy, anachronistic, or gimmicky, they’re actually one of the most expressive effects pedals you can buy. Most pedals are designed to be used in a decidedly static way – you set the controls the way that sounds best to you and then you simply play through it. A wah pedal is one of a small number of pedals designed to be used in a dynamic way – you interact with it to change the sound in real-time. In that sense it’s like a musical instrument. It requires developing some physical technique to play well and a player’s touch is key to the end result. Consequently, a guitarist’s wah sound can be highly individualistic just like his/her vibrato, phrasing, or bending. There are not many other effects pedals that can claim the same.

Far from just '70s porn soundtracks, a wah pedal can actually can be played in a lot of different ways. You can use it to morph tonal colors during your solos. You can do slow sweeps to impart a sense of motion onto chords or repetitive phrases. You can do uncanny vocal effects ala Steve Vai’s playing on the intro to Yankee Rose. You can leave the pedal in a fixed position to generate throaty, nasally, or piercing tones, like on Money For Nothing, Ziggy Stardust, or any number of Michael Schenker solos. And of course, you can and should, punctuate funk rhythms with a wah from time to time. Go on, admit it, it's fun to nurture your inner Shaft.

Who's the black private dick
That's a sex machine to all the chicks?
Ya damn right

One Man's Trash

Because wahs are played like an instrument, what makes a wah pedal “good” is even more subjective than normal. Obviously there’s the general tonality of a particular wah, the quality of which is already highly subjective. But there’s also the sweep range, the response curve, and the bandwidth (or “Q”) – all of these factors interact with the way you physically control the pedal. So what works really well with somebody else’s wah technique may not work so well with yours. It also makes the “wah comparison” videos on YouTube very inconclusive in my opinion. A lousy player can make a perfectly good wah sound like crap. You really have to physically play through a wah to know how well it’s going to work for you, even more so than with other pedals. As a result, I take peoples’ opinions about wah pedals with a healthy grain of salt.

Under The Hood

The electronic design of the original wah pedal is really simple. Like stupid simple. Just an inductor, a couple of transistors, a handful of resistors and capacitors, and a potentiometer. These dozen or so components are used to create a bandpass filter. The filter frequency has a resonant peak and is controlled by the potentiometer which is turned using the rocker pedal. Manufacturers have introduced some different designs over the years, but most modern wahs are still based on this original design with maybe some minor improvements for greater control, versatility, reliability, or consistency.

A lot of mojo has been built up around the inductor in a wah circuit. And the various types of inductors used over the history of the wah do in fact have markedly different sounds. But placing so much stock on the inductor alone is a bit of an oversimplification (as guitar tone lore tends to be). The other components have a significant effect on the sound and response too. The potentiometer will change the range, feel, and response of the sweep. The transistors impact the general tone. The resistors and their natural tolerances and age-related drift will affect the signal level, bandwidth, and frequency response. Like all guitar electronics, a wah pedal is a system of interdependent components that work together to produce the final result.

In my experience, Wah pedals break down a lot (the electronics do anyway). I tend to treat my gear well and I’m on my fourth wah pedal. Not because I’m fickle, but because the first three broke down! The act of using a wah pedal wears parts out and their design leads to really common problems (scratchy or broken pots, worn switches, etc.). The problems can be repaired and I repaired my last one at least 3 times that I can recall. But a wah is one of the few pedals that will almost certainly need to be repaired or replaced if you use it regularly, even if you’re really careful with it. The exception to this is the rocker pedal enclosure, which is quite robust and tends to have a much longer service life than the electronics. As a result, old malfunctioning wah pedals are frequent candidates for DIY circuit surgery and Frankenstein experiments. And that’s exactly what I intend to do with the old wah pedal that I replaced.

New Tricks

My past two wahs were garden variety Vox V847 pedals, which are basic, no-frills wahs that have essentially the same design as the original Clyde McCoy wahs (albeit with updated electronic components). I like the Vox wah. It’s dirt simple, it sounds good, and it’s not expensive. My biggest complaint is that it doesn’t come with true bypass switching so I installed it on both of my past Voxes.

But for my latest wah, I decided to embrace 50 years of presumed progress and get one with a few modern improvements. In particular, I liked the idea of having more control over the basic sound. I ended up choosing the Dunlop CAE MC-404. I liked the way it sounded, it had the right features, and it had some supposedly upgraded parts for reliability so maybe it will last a bit longer before needing repair.

The CAE's defining feature is the ability to select between two different inductors using a switch on the side of the pedal. The yellow inductor (the electronic component on the circuit board is actually yellow in color) is the "vintage" voiced inductor and is brighter in tone. The red inductor is supposed to be more "modern" sounding, which actually means it has more emphasis on low and low-mid frequencies as you sweep the pedal. In practice, I find the yellow one works well with clean and mid-gain tones and is voiced spot-on for classic '60s and '70s types of sounds. It is totally Shaft-approved. Can ya dig it? The red inductor is warmer and throatier sounding. Its sweep range is lower than the yellow inductor, so it has a nice growly sound in the pedal's heel-down position and works well with higher-gain tones. It gets your money for nothing and your chicks for free.

The CAE wah has a few other features as well. There's a switchable boost circuit with an external gain control. The boost can only be activated while the wah is on, which is an unfortunate limitation, but it sounds good. On the inside of the pedal are a couple of trim pots that control the Q (i.e. the bandpass filter's bandwidth) for each inductor, allowing you to personalize both wah voicings. That's a very nice feature, although it would be even better if the controls were on the outside of the pedal. There's another internal trim pot which controls the input gain of the wah circuit (this is separate from the boost feature I described earlier and is active whether the boost is on or off). Its usable range is limited because it will overdrive the circuit and even cause whistling feedback if you turn it up too much. I think it's best used to set the pedal at unity gain when the wah is activated and the boost is turned off, which is pretty close to how it's set up out-of-the-box. There are also LED status indicators for effect on/off, boost on/off, and the selected inductor, as well as a standard 9V negative-tip power jack. I've actually never had a wah pedal with LED status indicators and power input jack, which are table stakes on just about any other kind of effect pedal. They are very welcome features on a wah.

I dig the sound of this pedal. Before I auditioned it, I figured that I'd probably prefer one inductor over  the other and end up never actually switching between them. But I actually find myself switching between them a fair amount. If I want classic Hendrix, SRV, Isaac Hayes style wah, then yellow is the way to go. But the red inductor is really useful for "cocked wah" sounds and it works really well for high-gain sounds in my opinion. It's cool when you don't want the wacka-wacka sound and you want to do something a bit different.

So, there it is, just about everything I know about wah pedals, except for advice on how to actually play them. That will have to be a post, and probably a video, for another day.