Regarding the Crybaby inductors measuring close to the Fasels, Dunlop manufactures the Fasel inductors themselves and they started using them in their wahs years ago from what little research I did before I built my Shamwah. My donor unit was a 535Q and it's inductor was one of those metal enclosed inductors. I never thought to test the resistance at least with my multimeter.
So: I need to learn a bit more is what I'm finding. Seems like inductors will tend to be frequency-dependent, yeah? So the TC-1 probably tests at one frequency, and the LC at another. Or is it voltage dependent? Shit, I gotta get a better handle on this.
I know that inductance in AC signals tends to have the opposite effect of capacitence: inductance results in voltage leading current. The magnetic properties induced resist the flow of current when current is passed through the inductor. Beyond that I'm fuckin lost.
It is defined as an impedance, rather than as a resistance
Inductors are very similar to capacitors, in that they're opposites, for the most part.
Fuck you, that makes sense.
Caps store energy as an electric field.
A capacitor initially appears like an open circuit when power is first applied.
As voltage rapidly increases across a cap's terminals, current to and from those terminals decreases.
With AC, the electric field will charge and discharge. The timing of this is governed by the resistance of the circuit times the capacitence.
This is the RC time constant.
Inductors store energy in magnetic field.
And inductor Initially appears like a short circuit as power is applied.
As current flow rapidly increases across the inductor's terminals, voltage drop across those terminals rapidly decreases.
With AC, the magnetic field will charge and discharge.
The timing of this is governed by the resistance of the circuit times the inductance.
This is the RL time constant.
So...what does that all mean? It means that capacitors resist changes in voltage, and inductors resist changes in current.
Cool. So those are some of the basics.
Now I gotta read more.
*Edit: ok. Now I've read more*
Capacitors exhibit capacitive reactance, which will increase in resistance as frequency *decreases*, as capacitors resist changes in voltage.
Inductors exhibit indictive reactance, which will increase in resistance with as frequency *increases*, as an inductor resists changes in current.
The capacitor will have more time to recover, that is to charge and discharge it's stored voltage with lower frequencies, which impedes the transmission of lower frequencies.
Still trying to wrap my head around Inductive reactance, honestly. It sounds like it essentially is able to smooth out higher frequencies into a more "stable" waveform because they resist changes in current flow. The fiber points of how of the magnetic field that does this works eudes me though.
Maybe reading up on inductance of electric motor windings will connect a few dots?
Things like why the inductance of the windings naturally smooth out the stepped output of a VFD.
Here's some text books if you must
Maybe reading up on inductance of electric motor windings will connect a few dots?
Things like why the inductance of the windings naturally smooth out the stepped output of a VFD.
Here's some text books if you must
Yup. This is my speed. Commercial HVAC mechanic, after all.
But AC induction motors have an important difference: a rotor with an induced magnetic charge.
As the magnetized rotor passes over the poles, it creates back electromotive force. Back EMF isnt generated in a simple inductor, so decoupling the two ideas has been a bit of what I've been working on for the past few days in my free time.
Learning process. Hey, I went to college for psychology and switched when I realized that you could hit a machine with a wrench when it didn't behave the way you want it to without having any tense conversations with law enforcement afterwards.
I have tested most of the common wah inductors against generic Chinese 1:1 isolation transformers and found that they read much closer than you would think. But more importantly they often sounded better to my ear with only the highest end ones not losing to the cheap transformer.
I’ve also tested random NOS chokes and variable inductors against wah ones, and random old transformers to their modern counterpart. Results here are more mixed / to taste.
Did all this several years ago and wrote it down, I’ll have to dig it up and post it maybe revisit it now with better equipment
Honestly, though, my purposes here are more inclined towards objective findings - measurements - rather than what sounds good on a subjective level.
Though right now I'm just focused on inductance and resistance measurements.
The transformers I've tested thus far tend to have greater resistance measurements than the inductors. I'm also curious as to how the differences in materials effects things here: RG Keen's article on wah pedals makes mention of the wahs of old having inductors with potentially impure cores that may have held a magnetic field.
The theory went that, after some time with current passing through the inductor, the core would become partially magnetized. This magnetized core would act against the magnetic field induced by the inductor, which would cause some asymmetrical clipping when the inductor was driven hard.
It seems to me that a cheap transformer may use a more impure ferrite or even an iron core. That would certainly be more susceptible to permanent magnetization.
Cleaned up the spreadsheet, added another inductor from a 1992 crybaby, and edited my original post with new notes.
Also: if there's anything in here that I'm missing, additional measurements that would be useful, etc: please speak up. My main goal here is to cut through the bullshit and marketing that surrounds these. Any insight from our more learned forum members would be greatly appreciated.
Though I gotta say: just from looking at these, I'm pretty much on the "eh, use whatever" side of things.
Sure...it might shift frequencies around some. The "boutique" halos might get ya in a range that feels better to your ear. The yellow fasel or the EVH could have their own character that folks will gravitate towards.
But it's hard for me to see how many of the others would *really* be all that different from each other...and that there is enough variation between even the same *kind* of inductor that whatever changes one picks up on is, most likely, going to be due to *that*.
So yeah, I'd say if anybody is on the fence: the SBP ME-6 is a clear winner here for those that want a "modern" wah. For the cost, I doubt there's enough difference when we take inherent variability into the equation. Shoot, one could buy three for the price of a single fasel and pick the one they like best.
On another note I've ordered some ferrite toroids and 28awg transformer wire. Gonna try winding my own. Cause I'm nuts.
This is a treasure trove of info. I wish I understood more. I got my Shamwah back out tonight to fiddle with it. I had socketed a couple things on the board. I ended up trying to use some values I saw for the Clyde McCoy, but I think one of the things I needed to change wasn't socketed. I used an external b100k to replace the stock b50k trimmer.
Now I have a hankering to build another one and it's got me looking on ebay and reverb for old Crybabys.
Then we can go and fuck it up with our crazy ideas and impressions:
LIKE IM ABOUT TO DO RIGHT NOW!
I fucked around with some of these a few days ago. My impressions:
Whipple < Sabbadius Soul
Red Fasel #1 < ME-6
The big surprise here: I noticed something rather off-putting about the fasel: It seemed to crush all the sweep into a very narrow range of my potentiometer. Too drastic, too quick, not enough sweep to play with.
Granted, this could be due partially to the chase tone pot's taper and the interaction between those two components. I'll likely be resting out a few different pots too as I move along in my wah testing journey.
The ME-6 is great. No complaints. The Whipple is quite nice, but it has a bit of a flavor to it that strikes me as being a bit thinner and qackier than I tend to prefer.
The Sabbadius Soul is, so far, my favorite. It's got a kind of chewy character that I really like, while sounding a bit more, for lack of a better term, "modern" than the Whipple.
Bit keep in mind, with the exception of the fasel, I'd be hard pressed to accurately guess any of these out of a blind lineup. The differences are subtle and, in the grand scheme of things, only matter as much as one is willing to obsess over exceedingly small details.
Which, honestly, is my game.
I'm thinking I'm gonna update the chart with measurements at 4kHz possibly 120Hz too. I skipped those in the interest of getting this thing made quickly, but now I'm curious to revisit it.
Alright: here's another little sub-point in my research:
What the hell is up with all the different types? Pot core? Toroid core? Stack of Dimes? Halo? Cup core? The fuck!
Well, here's the rub: it's just a bit of ferromagnetic or ferromagnetic (don't ask, I don't know) material that's got some wire wrapped around it.
Seriously. That's it. For our purposes, we're either using iron (for many mini transformers) or Ferrite (for the majority of wah pedal inductors.
The core shape and material will influence the final measured inductance, and will play a significant role in how many turns of wire are required to achieve a certain inductance. All this can be figured out with math that is *way* beyond my two-dimensional pay grade.
So, I'm gonna laystickman it out as best I can.
Many of these terms are, essentially, colloquial. Magic words that make aging lawyers that play guitar think "man, back in my day I shoulda coulda woulda been the shit" when they plop down their cash for an old boomerang, or a Clyde picture wah, or whatever.
In truth, many of these don't really mean anything. As far as I can tell, "Halo" and "Stack of Dimes" are both *essentially* pot cores, just different shapes and geometries.
Pot core ferrite:
Then, there are toroid cores. These are little donut looking things. Toroids are yada blah enclosed magnetic *jerk off motion*, the upshot of which is that you can achieve the highest inductance with the least wraps of wire, and thus the lowest DC resistance, with this design:
Cup Core? I have to admit this one is a little bit of a mystery to me. Cup core ferrites certainly exist, but I have no idea how one makes an inductor out of one, nor how they differ from rod core ferrites.
I suppose one wraps around the outside. But information on this type is limited on Google (thanks, Dunlop, for marketing the yellow fasel this way)
And then, there's the E-type. This is the general transformer shape, and it looks like a capital E.
It *seems like* this is another sub-category that includes the likes of the ME-6, which has a different geometry but is distinct in that it has large exposed areas of the wind, as opposed to the pot core which only tends to have one or two narrow ports.
Which, by the way, the ME-6 uses an RM-6 ferrite core:
Each offers its own way of constructing an inductor: wire wraps around a suitable material. I'd be willing to bet the majority of the Dunlops are toroid core...I even suspect that the yellow fasel is a toroid, given it's low DC resistance.
Again, it doesn't *really* matter all that much. But I started this thread because I was curious, and there just seems to be *no* real, non-hype based information on these components.
There are other ways of making an inductor. Rod cores, plates, etc. But the basic pot core, toroid, and e type ferrites are what you're gonna find in 98% of what's out there.
