Wah Inductors. No hype. Just measurements.

Stickman393

Stickman393

Well-known member
Alright folks, I've been collecting wah inductors as I've been working towards a few different expression pedal projects.

So, curiosity. How do all these compare? I might put together a little trial wah pedal and cycle a bunch of these one-by-one, but I'm not particularly inclined to believe that my ears can really do all that much to tell the difference. But...I do have a TC-1, and that'll give some objective idea of how each of these compare in this extremely limited realm of "hey, resistance/inductace info?"

So take the following for what it's worth:

The numbers in parenthesis are from my Fluke 87+ and my honeytek LC meter.

Dunlop Yellow Fasel (cup core): 14.7 ohms/24.26mH (13.9 ohms/620mH)

Dunlop Red Fasel (toroid): 17.5 ohms/565.2mH (17 ohms/583mH)

Dunlop Crybaby GCB-95 (late 90's through early 00s) (Black plastic cylinder with white dot): 15.1 ohms/24.85 mH (14.6ohms/690mH)

Dunlop Crybaby GCB-95 (modern?) (black plastic cylinder with white paint dot): 17.8ohms/599.4mH (17.4 ohms/645mH)

Dunlop Hendrix crybaby (late 90s though early 00s) (black plastic cylinder with green paint dot): 14.1 ohms/14.03mH (13. 7ohms/564mH)

Dunlop Crybaby GCB-95 80's (Mexico): 12 ohms/76.78mH (11.8ohms/343mH)

Mammoth/SBP ME-6: 30.7 ohms/730.3mH (29.4 ohms/622mH)

Ruby Tubes tall plastic: 57.7 ohms/592mH (56.2 ohms/579mH)

Whipple Halo: 28.8 ohms/580.7mH (27.8ohms/522uH)

Sabbadius Soul Halo: 30.3 ohms/ 597.8mH (29.5 ohms/510mH)

Dunlop Crybaby 535 (Brass screw, exposed toroid): 17.8 ohms/582mH

Dunlop Crybaby 535q 18Vdc (metal can. shielded): 18.3 ohms/593.3mH

Dunlop EVH inductor: 14.8 ohms/15.83mH (14.4 ohms/666mH)**************************** fuck yea

Transformers!

TM-011-R:
Primary: 124.8ohms/2181mH
P Center tap: 62.3ohms/255.7
Secondary: 47.3ohms/357.1MH
S center tap: out of range

Tm018-R:
Primary: out of range (shows up as diodes)
P center tap: 271.4ohms/6059mH
(Secondary identical)

TM022-R
Primary: out of range (shows up as diodes)
P center tap: 276.8 ohms/5335mH
Secondary: 147.3ohms/3359mH
S center tap: 75.5/504.5mH

Hammond 142B:
Primary: out of range (diodes)
P Center tap: 389.8ohms/8415mH
Secondary: 215.4ohms/6448mH
S Center tap: 104.2ohms/885.8mH
 
Last edited:
This is cool. It would be nice to compare to some commonly available transformers that are sometimes used instead of inductors.
 
I've got about a grip of those.

I did a couple of quick tests, but I found that mine they tended towards higher resistance, and *much* higher inductance.

*Edit* added to original post.
 
Last edited:
I always wondered what the actual specs were on a lot of these inductors like the different red and yellow Dunlop ones since I've never seen them come out state what they were. Not that I actually understand how the resistance or henries effect the wah sound, but it would be nice to be able to compare them. I built a Shamwah! in my 595Q Crybaby enclosure and ended up reusing the inductor that came with it because I didn't know if or what the difference would be.
 
I hear you. I've been reading and re-treading RG Keen's article on wah pedals in an attempt to really *get it*. But my brain is made of sticks.

I know a little about Inductance and capacitence as an HVAC tech. Mostly in how they affect power factor.

Something that interests me is a note that RG KEEN has in reference to magnetization of the inductor core, and how it could possibly cause the inductor to clip asymmetrically.

If one was to run a bit of current through one of the transformers listed, one could easily create a bit of magnetic offset.

The 42TM022 would be ideal for that. Use the secondary center tap for the inductor. Run 9vdc through a 390r or 470r resistor and a 1k or larger trimpot to the primary to center windings. Kinda want to give that a shot, TBH.
 
For those who are interested in the 42TM series, boom. There's the datasheet.

This is largely in line with my measurements. It'd be nice if I had a better LCR meter, but my TC-1 will do for now.
 
*record scratch*

Hey. So I pulled another black plastic cylinder crybaby inductor out of another crybaby pedal.

This guy measured, in fact, at 17.8ohms and 599.4mH

So: there definitely seems to be variation on these little jobbies depending on the year the pedal was made.

I have no clue when this guy was made. It's worth mentioning that there that the low and high mH variations are not easily distinguishable.
 
Stickman393 said:
*record scratch*

Hey. So I pulled another black plastic cylinder crybaby inductor out of another crybaby pedal.

This guy measured, in fact, at 17.8ohms and 599.4mH

So: there definitely seems to be variation on these little jobbies depending on the year the pedal was made.

I have no clue when this guy was made. It's worth mentioning that there that the low and high mH variations are not easily distinguishable.
Click to expand...
I guess they must have found a way to get the same filter response with a lower value inductor? This is a bit over my head for me but I guess playing with R and C and whatever opamp stage would do it?
 
giovanni said:
I guess they must have found a way to get the same filter response with a lower value inductor? This is a bit over my head for me but I guess playing with R and C and whatever opamp stage would do it?
Click to expand...
In the ballpark will work since you're sweeping the filter anyway. Inductor variation along with pot variation is probably the source of many opinions on different wahs. Each one probably has a little difference in sweep and Q as a result.
 
My theory:

It's possible that the "fasel" inductors are simply the same as their two *modern* black cylinder inductors.

Why would they make two identical inductors, with only cosmetic differences? Probably so they can sell fasels to folks that don't know any better. I dunno. Or convince folks to switch to the classic? I dunno.

This is the same company that had the nerve to call a new line the "crybaby classic", fuck with the circuit, switch to all SMD, and just plop a fasel and a non-sealed potentiometer into it.

Wild.

But...Take a look at the red fasel and the most recent crybaby inductor I measured. Pretty damn close. Well within what I imagine tolerance for a part like this would be, especially when we take the uncertainty introduced by the TC-1. This black plastic variant has a white paint spot on it.

Then, check out the yellow fasel and the crybaby inductor. Huh. Super close. This black plastic variant has a green paint spot on it.

Granted: the one that measured in the 25mH range has a white paint dot on it too.

(Why do I have so many different inductors? I've been buying up all the cheap broken crybabies online. Sorry guys)
 
Last edited:
Stickman393 said:
My theory:

It's possible that the "fasel" inductors are simply the same as their two *modern* black cylinder inductors.

Why would they make two identical inductors, with only cosmetic differences? Probably so they can sell fasels to folks that don't know any better. I dunno. Or convince folks to switch to the classic? I dunno.

This is the same company that had the nerve to call a new line the "crybaby classic", fuck with the circuit, switch to all SMD, and just plop a fasel and a non-sealed potentiometer into it.

Wild.

But...Take a look at the red fasel and the most recent crybaby inductor I measured. Pretty damn close. Well within what I imagine tolerance for a part like this would be, especially when we take the uncertainty introduced by the TC-1. This black plastic variant has a white paint spot on it.

Then, check out the yellow fasel and the Hendrix crybaby inductor. Huh. Super close. This black plastic variant has a green paint spot on it.

Granted: the one that measured in the 25mH range has a white paint dot on it too.

(Why do I have so many different inductors? I've been buying up all the cheap broken crybabies online. Sorry guys)
Click to expand...
I wonder what the EVH inductor measures at. Seems to frequently be the cheapest option of the Dunlop ones through replacement parts sellers
 
Added the EVH inductor.

I discovered that I have another capacitance meter that also measures inductance. It's a cheapie as well: a Honeytek A6243L.

That said: fucking hell. What?

It kinda turns my assumptions about these things upside down. Some of these measurements are *way* far off.

I might end up having to get a decent LCR meter after all: not sure I can trust *either* of these.
 
Stickman393 said:
I might end up having to get a decent LCR meter after all: not sure I can trust *either* of these.
Click to expand...
I mean. You don't have to.
I'm kinda surprised you don't have a high dollar fluke that can do the job.
Or get an Analog Discovery and measure them in circuit
 
Nah dude, I'm cheap as hell.

That fluke is my work multimeter. I'd never plop down that kind of coin for a multimeter. Cause I constantly try to get away with the cheapest option that can...like...sorta reasonably work for my immediate need but because I'm really, really bad at planning and somehow end up constantly broke.
 
You must log in or register to reply here.
Back
Top