Wah Inductors
It seems a little unusual to have an article on just one part that goes into a wah-wah pedal. In fact, there are circuit designs for wah-wah pedals that don't use an inductor. The reason so many wah-wah pedals have an inductor is because of the design and success of the first wah-wah pedal manufacturer: Thomas Organ Company, and by extension Vox. Thomas Organ employed the inventor of the Wah-wah, when he invented it: Brad Plunkett. We have also included this as its own separate page as we have engaged ourselves to the craft of winding some of our own wah-wah inductors. We didn't do this because we have "secret sauce". If there is any "secret sauce", we do our best to demystify it below. The reason we're winding our own inductors is:
- For our own rental wah-wah pedals
- Because we will be selling coil-tapped inductors that will allow a pedal builder to access more than one kind of tone without installing multiple inductors on the same PCB.
History
Brad took his design for the wah-wah pedal from a tone control that was part of another piece of equipment. It's believed this unmentioned piece was a keyboard amp. The wah-wah pedal, like most great inventions, came about completely as the result of an accident. In 1966, the owner of Thomas Organ, Joe Benaron, wanted to lower the cost of the Vox Super Beatle amp(and probably others).
On certain Vox amplifiers, including the Super Beatle, was a switch called the "MRB". This "MRB" switch stood for "Mid Range Boost". As you can imagine, it boosted the midrange frequencies. However, the cost of this switch was about $4.00 in 1966-1967.
Plunkett's task was to make the amps more profitable for Thomas Organ by lowering the cost on the amps. By redesigning the amp circuit to use a $0.20 potentiometer instead of a $4.00 switch (presuming the buying public would accept such a change), the amp would become more profitable...
One morning, in the span of about 4 hours, Plunkett had built a new variation of the previously-mentioned tone control into a sweepable tone control. After some experimentation in the office with this new control, it took on a life of its own. An unused treadle housing for a foot-swept volume control organ pedal was repurposed, and the first ever wah-wah pedal was born. Needless to say, this innovation captured the imagination of the people at Thomas Organ / Vox and it was released as a standalone product. Jim Dunlop actually made a YouTube feature about the Crybaby wah-wah pedal that we love called "Crybaby: The Pedal That Rocked The World". It will also randomly pop up from time to time, without notice to YouTube, and will be similarly withdrawn from YouTube without notice. The link provided may or may not work.
Thermionic Inductors
When most people think of an inductor as a component that gets wired into a wah-wah circuit, it's considered something of a black box. You want a different sound in your wah-wah? Replace your current inductor (the "Plain Jane Dunlop", for example) with another (the "Dunlop Red Fasel"). And this will change the sound. And yet it might not get you the sound you're looking for...
We have, ourselves, gone down the rabbit hole, and quite unintentionally. Being fascinated by wah-wahs and wanting to build a better one than can be bought at Guitar Center or Sweetwater, we bought multiple wah-wah inductors with the goal of making "a better sounding wah-wah".
Track to a few years later, and we learned that "winding your own" wah-wah inductor isn't much more effort than winding your own electric guitar pickup. "No kidding? Not different than a pickup? Really? Winding a pickup mostly consists of a few thousands turns of very thin enameled wire..."
And that sent us down the wind-it-yourself inductor rabbit hole.
We have spent multiple hours to try to understand what it takes to identify and assemble the correct pieces in order for someone to wind their own wah-wah inductors. An inductor consists of top and bottom ferrite core halves, a coil former, yoke, assembly, and adjusting screw. Not all inductors come with a screw. The screw isn't to hold the inductor together, it serves to act as an insert to move up and down and adjust the gap between the two ferrite core halves. A wah inductor needs a gap, as it is necessary for the inductance of the part. If the gap is too small, the core will saturate and inductance will drop, and if the gap is too large, inductance is harder to create. With the coil-based, non-toroidal inductors that we're building there seem to be only 3 types that go into wah-wahs. "Stack of Dimes", "Halo", and the "ME-6". Toroidal inductors make up the preponderance of the inductors from Dunlop, including red and yellow "Fasels".
So we're winding some of our own inductors. We're going to wind each of the "flavors" of coil-based inductors. Here's what our investigations lead to with respect to ordering the parts. We found that Mouser seems to have the most breadth and depth of inductor parts. So here are the components codes to look up the various pieces so as to be able to wind your own inductor.
NOTE The parts listed below will allow anyone to build their own inductor. The parts are grouped according to the inductor that one might wish to assemble.
HOWEVER Mouser doesn't always have all quantities of all components available at all times. The components listed below were included because at the time this page was updated with the component information, these components were available as individual pieces and didn't require bulk (1000+ pieces) order. Depending on when you're reading this entry, that information may be out of date and you may need to rummage through the Mouser site (or other sites like Digikey or RS-Online), so as to be able to order the correct parts in the appropriate quantities.
ADDITIONAL NOTE There is a legitimate case for manually removing ferrite core material to enlarge an inductor gap rather than using a screw to close a larger gap. The "Fair-Rite" options, included below, are less expensive, but the gap of the Fair-Rite pieces available from Mouser is unknown. We have done our best to pick the tightest gap so that material could be removed. As previously stated, such an inductor should need no inductance tuning screw as tuning will presumably be done by ferrite removal via a piece of sandpaper.
Stack of Dimes / 1408
| Manufacturer | Part Number | Inductor Assembly Piece |
|---|---|---|
| TDK | B65549E0004X023 | Inductance Tuning Screw |
| TDK | B65545B0009X000 | Yoke (Harness) & 4-Lug Terminal Carrier |
| TDK | B65542B0000T001 | Coil Former |
| TDK | B65541T0250A048 | Ferrite Coil halves (0.10 mm gap) w/ threaded insert |
| Fair-Rite | 5678140921 | "Fair-Rite" branded Ferrite Coil - no insert - tight gap |
Halo / 1811
| Manufacturer | Part Number | Inductor Assembly Piece |
|---|---|---|
| TDK | B65659F0001X023 | Inductance Tuning Screw |
| TDK | B65655B0009X000 | Yoke (Harness) & 4-Lug Terminal Carrier |
| TDK | B65542B0000T001 | Coil Former |
| TDK | B65651D0000R048 | Ferrite Coil halves zero gap - sand paper to tune |
| TDK | B65651T0400A048 | Ferrite Coil halves (0.10 mm gap) w/ threaded insert |
| TDK | B65651T0250A048 | Ferrite Coil halves (0.20 mm gap) w/ threaded insert |
| Fair-Rite | 5695181221 | "Fair-Rite" branded Ferrite Coil - no insert - tight gap |
"Wedge" / RM-6
| Manufacturer | Part Number | Inductor Assembly Piece |
|---|---|---|
| TDK | B65659F0001X023 | Inductance Tuning Screw |
| TDK | B65808B2203X000 | Clamp (harness), 1-piece (two needed!) |
| TDK | B65808N1004D001 | Coil Former with 4-pin Lug |
| TDK | B65807J0400A048 | Ferrite Coil halves zero gap - sand paper to tune |
| TDK | B65807N0250A048 | Ferrite Coil halves (0.12 mm gap) w/ threaded insert |
Impact
Most musical electronics professionals who've looked into the wah-wah pedal agree that the inductor, in and of itself, is not the most important piece of circuitry. It's clear from outside experimentation that adjusting other, more mundane pieces of the circuit can also have a large effect on a wah wah pedal's tone. However, since the inductor continues to capture the imagination of people around the music world as the "silver bullet" in a wah-wah pedal, we've decided to offer the "wah inductor" its own page.
Various Inductors
Dunlop
- Red Fasel Toroidal Core
- Yellow Fasel Cup Core
- Dunlop Halo
- Dunlop EVH
- Dunlop "Standard" Black
Joe Gagan
- Joe Gagan's Tone Tank
- Joe Gagan's 60s purple tone tank
- Joe Gagan's red tone tank
Arteffect.co
- Arteffect Halo
- Arteffect stack-of-dimes
- Arteffect stack-of-halos
MammothElectronics.com
- Mammoth Electronics ME-6
Dandyjob.com
- Dandyjob.com "Whipple" Halo
Fulltone.com
- Fulltone Silver Can Inductor
Miscellaeneous Inductors
- TDK 5103 "cube"
- Castledine Halo
- ArielFX Halo
- Chasetone.com "Stack of Dimes"
- Stuff to note and update
- Dunlop "Standard" black cylinder - not seen a price, comes installed in base model dunlop wahwahs, can be gotten on eBay
- Dunlop "Yellow" cup-core - Price varies, seen low of $12.00 on tubesandmore.com, high of $20.00 from Dunlop
- Dunlop "Red" toroidal core - Price varies, seen low of $12.00 on tubesandmore.com, high of $20.00 from Dunlop
- Dunlop EVH "black signature" inductor - Price varies, seen low of $19.00 on Dunlop, high of $35.00 from eBay
- Whipple Halo Inductor - $27.00 dandyjob.com / eBay
- Arteffect.co Stack-of-Dimes inductor - $29.00, must await shipping from Israel
- Arteffect.co Halo Inductor - $31.00, must await shipping from Israel
- Arteffect.co Stack-of-halos - $25.00, must await shipping from Israel
- Joe Gagan's "Original El-Rad Tone Tank" - $22.77 on eBay. Joe Gagan has FB page, but no business website
- Joe Gagan's "Red Tone Tank" - $22.95 on eBay. Joe Gagan has FB page, but no business website
- Joe Gagan's "Purple 60s Vox Tone Tank" - $27.77 on eBay. Joe Gagan has FB page, but no business website
- TDK - 5103 inductor - Doesn't seem like it's available anymore except to be cannibalized from old electronic equipment - doesn't have a good reputation for musicality, but per Joe Gagan, the TDK 5103 came in two flavors - low impedance and high impedance with the low impedance inductor reported by Joe as sounding fantastic.
- Mammoth Electronics "ME-6" Inductor - $8.00 / Mammoth Electronics
- Fulltone "Silver Can" inductor - $49.00 / Fulltone.com
- Chasetone.com stack-of-dimes $17.99 / eBay
Sites that Offer Wah Stuff
- arteffect.co: home-spun inductors. Also sells pots.
- JimDunlop.com: Saved the Crybaby Wah-Wah from oblivion.
- eBay.com: Search for "Joe Gagan", "Chasetone", "Dandyjob", or "Whipple" for more specialized stuff.
- area51tubeaudiodesigns.com: No idea why the site is "Tube Audio" when it's all wah-wah. Sells switches, pots, custom wah wahs
- realmccoycustom.com: Geoffrey Teese "RMC" boutique wah wah. Other models as well.
- chasetone.com: Wahs and other pedals, but no inductors. Chasetone has only sold self-wound inductors on eBay (we have one).
- www.wah-wah.co.uk: Castledine Electronics. We think we'd like a "Wizard" pedal by Castledine too...
- chicagoiron.com: Sells clones of the no-longer-available Parachute Wah Wah by TycoBrahe. Tony Iommi loves them.
- Additional Sources
