masonlewisdiesel
Member
I'm on the home stretch!! gonna be a late night
Wah Inductors. No hype. Just measurements.
- Thread starter Stickman393
- Start date
Stickman393
Well-known member
So I'm lagging like fuck on my international shipments. But I'm gonna add in a little extra somethin somethin for yall.
As for now, I've added a few more inductors to my original doc, and I've made this one comparing various potentiometers:
Other notes:
Mission rewah: this guy ain't made no more. Got two of em. The standard and the pro. Gonna trace em out and see what the little dip switches on the inside do. Got a feeling about a couple of 'em.
Looks like the only difference between the "pro" and the standard is the inductor. The "pro" uses a cine-mag crossover inductor with several different taps on it. The only tap that is actually used is the 520mH tap: all the rest are electrically isolated from the circuit. I had read some speculation online that the little internal dip switches on this guy would switch between the taps on the inductor: this is not the case.
The standard model uses a yellow fasel. Which is a great inductor.
The biggest difference between the two? The cine-mag inductor has the highest q I think I've ever measured in the 4k range.
I've also picked up a few off brand wahs to check out: the Tech 21 Killer Wail, made by Onerr, uses a toroid that initially measures pretty "blah", but sounds damned decent in practice. They achieve this by adding a 47 ohm resistor in series with the inductor coil, bumping the "q" resistor and input resistor to 100K, and dropping the resistance off the emitter of Q1 to 220 ohms. Makes for a decent little wah!
I've also picked up an Ibanez WF-10 that is in *shitty* condition. I'm not sure if I'm gonna try to salvage the plastic enclosure or not yet: trying to 3d print the enclosure has been an exercise in failure, I need to invest in a dedicated support filament in order to make this thing work.
Also bought a Twin Peaks cause I wanted to crack it open and see what they did on the inside. All SMD. dammit...
As for now, I've added a few more inductors to my original doc, and I've made this one comparing various potentiometers:
Wah Pots
docs.google.com
Other notes:
Mission rewah: this guy ain't made no more. Got two of em. The standard and the pro. Gonna trace em out and see what the little dip switches on the inside do. Got a feeling about a couple of 'em.
Looks like the only difference between the "pro" and the standard is the inductor. The "pro" uses a cine-mag crossover inductor with several different taps on it. The only tap that is actually used is the 520mH tap: all the rest are electrically isolated from the circuit. I had read some speculation online that the little internal dip switches on this guy would switch between the taps on the inductor: this is not the case.
The standard model uses a yellow fasel. Which is a great inductor.
The biggest difference between the two? The cine-mag inductor has the highest q I think I've ever measured in the 4k range.
I've also picked up a few off brand wahs to check out: the Tech 21 Killer Wail, made by Onerr, uses a toroid that initially measures pretty "blah", but sounds damned decent in practice. They achieve this by adding a 47 ohm resistor in series with the inductor coil, bumping the "q" resistor and input resistor to 100K, and dropping the resistance off the emitter of Q1 to 220 ohms. Makes for a decent little wah!
I've also picked up an Ibanez WF-10 that is in *shitty* condition. I'm not sure if I'm gonna try to salvage the plastic enclosure or not yet: trying to 3d print the enclosure has been an exercise in failure, I need to invest in a dedicated support filament in order to make this thing work.
Also bought a Twin Peaks cause I wanted to crack it open and see what they did on the inside. All SMD. dammit...
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Stickman393
Well-known member
Updates:
I'm dying to build a little wah pot tester. Something that I could, say, stick a pot in, directly tie the shaft of a stepper motor to, and run a program where it spins the pot from min to max and auto-populate an excel sheet with the resistance over its travel.
I had done the previous one by simply turning by hand until each tooth of the gear lined up with the center. It works, but there's a hell of a lot of room for measurement errors, as wah pots tend to have a very specific obtuse-z shaped weep to em, where the majority of the change is in a small portion of the shaft travel.
That'll require acquiring new skills. Not much of a programmer. But I can probably figure it out.
Sad news: fucking, god dammit El Rad. In the process of trying to pull an El Rad 500mH inductor from an EHX crying tone pedal, I learned the hard way that they constructed those with toroids, soldered the ends to basic bus wire leads, popped the assembly in a plastic cup, and filled the contraption with a dielectric dope with a very low melting point. That is to say: upon trying to de-solder the thing a lead popped out of the thing with like, no effort. So, balls.
So, I pulled the toroid out. Couldn't seem to grab the wire that fell off in all the dope. Fucking thing. So, I was hoping to get an el-rad on the sheet...but it's starting to look like I'll need to re-wind that thing by hand if I want to get an idea of what that one's like.
Its a big ol oopsie, cause crying tone pedals and boomerangs use El Rads. Woulda been great to have added that to the list, and those pedals are fuckkking expensive on the vintage market.
Oh well.
I've upgraded my setup: the motor side of my coil winder with some PET-CF17. Much stiffer than my old PETG build. I'll probably swap the stabilizer side as well, but that'll take some doing. Bearings are a PITA to slide onto a shaft.
I've also been experimenting with an 1107 size, ala stack of dimes. Size comparison with a 1811. Both wound about 520mH@1K.
I'm dying to build a little wah pot tester. Something that I could, say, stick a pot in, directly tie the shaft of a stepper motor to, and run a program where it spins the pot from min to max and auto-populate an excel sheet with the resistance over its travel.
I had done the previous one by simply turning by hand until each tooth of the gear lined up with the center. It works, but there's a hell of a lot of room for measurement errors, as wah pots tend to have a very specific obtuse-z shaped weep to em, where the majority of the change is in a small portion of the shaft travel.
That'll require acquiring new skills. Not much of a programmer. But I can probably figure it out.
Sad news: fucking, god dammit El Rad. In the process of trying to pull an El Rad 500mH inductor from an EHX crying tone pedal, I learned the hard way that they constructed those with toroids, soldered the ends to basic bus wire leads, popped the assembly in a plastic cup, and filled the contraption with a dielectric dope with a very low melting point. That is to say: upon trying to de-solder the thing a lead popped out of the thing with like, no effort. So, balls.
So, I pulled the toroid out. Couldn't seem to grab the wire that fell off in all the dope. Fucking thing. So, I was hoping to get an el-rad on the sheet...but it's starting to look like I'll need to re-wind that thing by hand if I want to get an idea of what that one's like.
Its a big ol oopsie, cause crying tone pedals and boomerangs use El Rads. Woulda been great to have added that to the list, and those pedals are fuckkking expensive on the vintage market.
Oh well.
I've upgraded my setup: the motor side of my coil winder with some PET-CF17. Much stiffer than my old PETG build. I'll probably swap the stabilizer side as well, but that'll take some doing. Bearings are a PITA to slide onto a shaft.
I've also been experimenting with an 1107 size, ala stack of dimes. Size comparison with a 1811. Both wound about 520mH@1K.
What if you couples the pot with a larger gear couples to a much smaller gear and plotted the pots to each turn of the smaller gear(which has a handy little handle.
Would be a bit of filament but analog enough to not be toooo tough. Or repurpose a bike gear with a 3d printed gear. I'm sure some of the local nerd have a a spare bike gear made of titanium they could donate to the madness, err..., effort.
Just be careful not to get caught in the machine. Would hate for you to get corrugated.
Would be a bit of filament but analog enough to not be toooo tough. Or repurpose a bike gear with a 3d printed gear. I'm sure some of the local nerd have a a spare bike gear made of titanium they could donate to the madness, err..., effort.
Just be careful not to get caught in the machine. Would hate for you to get corrugated.
Stickman393
Well-known member
I'm uncorrugatable. Lucky for me, corrugation requires a third dimension.
Honestly, a stepper-to-pot setup would be the easier option here. Just requires a 1/8" to 1/4" coupling and a couple bits of L-bracket designed to be mounted parallel to each other.
Stepper motors are about 200 steps a rotation, It would be easy enough to configure that thing with 16x microsteps and achieve a resolution of 3,200...or roughly 0.1125⁰ a step. For a 300⁰ pot, that represents potentially 2,666 potential data points.
Probably overkill.
Truthfully, the easier way to do this would probably be time-based. Take a measurement every half second and configure a full 300⁰ turn to take 1 minute. Synchronize the starts. That sort of thing.
Honestly, a stepper-to-pot setup would be the easier option here. Just requires a 1/8" to 1/4" coupling and a couple bits of L-bracket designed to be mounted parallel to each other.
Stepper motors are about 200 steps a rotation, It would be easy enough to configure that thing with 16x microsteps and achieve a resolution of 3,200...or roughly 0.1125⁰ a step. For a 300⁰ pot, that represents potentially 2,666 potential data points.
Probably overkill.
Truthfully, the easier way to do this would probably be time-based. Take a measurement every half second and configure a full 300⁰ turn to take 1 minute. Synchronize the starts. That sort of thing.
Stickman393
Well-known member
Well folks, I got my first vox, and right away it went under the knife.
VOX wahs have never been appealing to me due to the fact that they're...well...
Here's the rub. Vintage vox wahs we're often made by the same Thomas Organ factories as crybabies, and they were built using the same parts. Thing is: they command a heftier price on the vintage market than the Thomas organ branded wahs. As such, given the increased cost of picking one up and the fact that it likely won't show any real difference over the TO's, I've skipped over those.
When vox wahs came back in the 90s or so, they were made by Dunlop. They retained the old ref F or so circuit board layout with some minor changes to power supply filtering, and Dunlop components. Easy enough to see by pictures, no need to buy one and pull it apart.
Nowadays, most Vox wahs are made in China. They use a combination of SMD and through hole components, and TBH I'm not super interested in many of the more modern mass-produced pedals. And they're still like 50 bucks minimum. Eh. I'm fine.
This one piqued my interest though. The Joe Satriani Big Bad Wah. Dual inductor model, foot switchable. Huh!
So, I took a look. Got one for a song. And I've added an additional page comparing the two inductors in this pedal.
The result? Huh. Pretty similar. The biggest differences are in Q, where the taupe inductor is generally higher, and in measured inductance, where the taupe starts lower and ends higher than the black.
Overall, though? Subtle. Not much difference. These measure quite similarly to many of the Dunlop toroids, so I suspect that they're using toroids in these.
Anywho, I added an extra page to my doc looking at those two.
VOX wahs have never been appealing to me due to the fact that they're...well...
Here's the rub. Vintage vox wahs we're often made by the same Thomas Organ factories as crybabies, and they were built using the same parts. Thing is: they command a heftier price on the vintage market than the Thomas organ branded wahs. As such, given the increased cost of picking one up and the fact that it likely won't show any real difference over the TO's, I've skipped over those.
When vox wahs came back in the 90s or so, they were made by Dunlop. They retained the old ref F or so circuit board layout with some minor changes to power supply filtering, and Dunlop components. Easy enough to see by pictures, no need to buy one and pull it apart.
Nowadays, most Vox wahs are made in China. They use a combination of SMD and through hole components, and TBH I'm not super interested in many of the more modern mass-produced pedals. And they're still like 50 bucks minimum. Eh. I'm fine.
This one piqued my interest though. The Joe Satriani Big Bad Wah. Dual inductor model, foot switchable. Huh!
So, I took a look. Got one for a song. And I've added an additional page comparing the two inductors in this pedal.
The result? Huh. Pretty similar. The biggest differences are in Q, where the taupe inductor is generally higher, and in measured inductance, where the taupe starts lower and ends higher than the black.
Overall, though? Subtle. Not much difference. These measure quite similarly to many of the Dunlop toroids, so I suspect that they're using toroids in these.
Anywho, I added an extra page to my doc looking at those two.
Stickman393
Well-known member
Couple recent additions:
I just got an older JEN Crybaby super. Its got one of the original red Fasel inductors, and the plastic cap was coming off a bit. So, I figured, let's take a look:
Yup, lo and behold, it is a 1408 pot core. Strange one: typical pot cores I see only have two openings. No indication to the grade of the ferrite, no markings whatsoever.
I added that one to my list. High Q, and it ranks amomgst the highest measured inductance values I've checked. And quite different than the white fasel in my first JEN.
Variation? Different materials? Hard to say. Only have a sample size of two.
I also included another recent acquisition: a shin-ei. Transformer-based wah. That one is *remarkably* unique. Its Q is flat across the frequency range, and it starts high and ends low.
I just got an older JEN Crybaby super. Its got one of the original red Fasel inductors, and the plastic cap was coming off a bit. So, I figured, let's take a look:
Yup, lo and behold, it is a 1408 pot core. Strange one: typical pot cores I see only have two openings. No indication to the grade of the ferrite, no markings whatsoever.
I added that one to my list. High Q, and it ranks amomgst the highest measured inductance values I've checked. And quite different than the white fasel in my first JEN.
Variation? Different materials? Hard to say. Only have a sample size of two.
I also included another recent acquisition: a shin-ei. Transformer-based wah. That one is *remarkably* unique. Its Q is flat across the frequency range, and it starts high and ends low.
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Stickman393
Well-known member
Updates:
Snarling Dogs. Got me one of these novelty gas pedal monstrosities. It uses a toroid and it's fucking weird. Low Q, S curved inductance.
The circuit board is laid out for a transformer, not an inductor. I've read that on the earlier pedals they had to swap out a *ton* of those transformers cause of poor shielding and noise. I'm inclined to believe that they didn't give it much thought to be honest, from reading about that particular company.
On the horizon...two I just got today:
One is old. The other is new.
Snarling Dogs. Got me one of these novelty gas pedal monstrosities. It uses a toroid and it's fucking weird. Low Q, S curved inductance.
The circuit board is laid out for a transformer, not an inductor. I've read that on the earlier pedals they had to swap out a *ton* of those transformers cause of poor shielding and noise. I'm inclined to believe that they didn't give it much thought to be honest, from reading about that particular company.
On the horizon...two I just got today:
One is old. The other is new.
drgonzo1969
Well-known member
Sweet! I didn't know vintage Fender Fuzz Wahs came with detachable Star Wars landspeeders inside them. BONUS!!!
jessenator
Well-known member
Stickly-wan Kenobi be like
drgonzo1969
Well-known member
"These are not the toroids your looking for."
GAStan
Active member
On your automatic pot tester, what about using a digital encoder to determine shaft angle? An encoder puts out pulses as it rotates. Stepper motors with feedback use these for the feedback. Using one by itself may be easier to program (I'm not a programmer, just going on the theory of less moving parts). This would still require manually turning the pot but would take out virtually all shaft angle related error.
Stickman393
Well-known member
SOLID idea! In fact, it would probably take less overall work if I was to do away with the automation aspect.
All I would need is a voltage readout and an angle readout. I could input by hand.
Another option, for sure.
GAStan
Active member
Something like this is what i had in mind:
Rotary Encoder
Rotary Encoder
Does anybody know what toroid is inside a fasel wah?
I’ve build pedal kits for a while now but never had a go at my own inductors.
I’ve bought a wah inductor kit from a place in Germany which has a bobbin, n48 pot core, clip and the terminal, similar looking to the “halo” i think.
The fasels look simple enough though - just a toroid, wire, mount and cover.
I’ve found a place in the UK that has a similar mount that “might” work (similar size etc) but am unsure about what toroid to use:
powermagneticsstore.co.uk
Anyone know whats in the fasels?
I’ve build pedal kits for a while now but never had a go at my own inductors.
I’ve bought a wah inductor kit from a place in Germany which has a bobbin, n48 pot core, clip and the terminal, similar looking to the “halo” i think.
The fasels look simple enough though - just a toroid, wire, mount and cover.
I’ve found a place in the UK that has a similar mount that “might” work (similar size etc) but am unsure about what toroid to use:
VTM620-2
VTM620-2 Vertical Toroid Mount (2 Pin) Material: PBT (Black) Solderability: Per MIL-STD-202; Method 208 2 Terminals: For vertical mounted inductors or current sensors. Terminals are shipped in the horizontal position to facilitate toroid lead connection,
Stickman393
Well-known member
Its likely an MnZn ferrite, TDK's n30 or n48 is probably a good place to start. ~14mm diameter. You'll have a tough time tracking down the exact specs, dunlop is gonna keep a tight lock on that info.
That said...toroids are tricky. Its possible to wind one for a wah by hand, but it's a bear. The wires are fine and getting the spacing right is critical.
Dunlop's modern day fasels are going to be machine-wound. There are designs online for toroid winding machines if you have access to a 3d printer, but they're meant for toroids that are more in the 140mm diameter range.
Its a tricky proposal. Honestly: I haven't experimented much with toroids. Never felt the need, truthfully.
While I can't say any of the below for certain, this is the impression I get:
I think it's extremely likely that the transition to toroids for Dunlop was done purely for cost cutting reasons. Pot cores are easy to make, but their assembly and production leaves a lot of openings for QA issues. The halves need to align, the mating surfaces need to be perfectly clean, they need to be clamped with sufficient force and glued, etc.
Toroids, on the other hand, don't suffer from those production issues. They also seem to require a bit less wire, which will save on production costs.
So, I suppose what I'm saying here is that it can be done, but each route requires a bit of work towards honing a process to get a consistent result. Building toroids would be easier, but making a jig or machine to help wind them is going to be more difficult. Pot cores are more difficult to build, but making a machine or jig to wind them is going to be easier.
That said...toroids are tricky. Its possible to wind one for a wah by hand, but it's a bear. The wires are fine and getting the spacing right is critical.
Dunlop's modern day fasels are going to be machine-wound. There are designs online for toroid winding machines if you have access to a 3d printer, but they're meant for toroids that are more in the 140mm diameter range.
Its a tricky proposal. Honestly: I haven't experimented much with toroids. Never felt the need, truthfully.
While I can't say any of the below for certain, this is the impression I get:
I think it's extremely likely that the transition to toroids for Dunlop was done purely for cost cutting reasons. Pot cores are easy to make, but their assembly and production leaves a lot of openings for QA issues. The halves need to align, the mating surfaces need to be perfectly clean, they need to be clamped with sufficient force and glued, etc.
Toroids, on the other hand, don't suffer from those production issues. They also seem to require a bit less wire, which will save on production costs.
So, I suppose what I'm saying here is that it can be done, but each route requires a bit of work towards honing a process to get a consistent result. Building toroids would be easier, but making a jig or machine to help wind them is going to be more difficult. Pot cores are more difficult to build, but making a machine or jig to wind them is going to be easier.
I have a yellow fasel which was dead (i’ve had it a while but couldnt get any readings) - i’ve opened it up today and it’s definately toroid.
Looked like the wire going to one of the pins was broke close to th toroid.
I’ve prized it out of the cup and removed the wires - on my digital calipers it measures 12.7mm x 7.7mm x 6.4mm and looks grey painted but i cant see any codes/writing on it.
I’ve got some 38awg wire so might as well have a go at rewinding it.
Any ideas how many winds it will need?
I was hoping to try unravel the original wire to get an approximate length but it was partially covered in some resin or goop.
The mount and cover are in good condition though.
Took a while to prize it out.
Looked like the wire going to one of the pins was broke close to th toroid.
I’ve prized it out of the cup and removed the wires - on my digital calipers it measures 12.7mm x 7.7mm x 6.4mm and looks grey painted but i cant see any codes/writing on it.
I’ve got some 38awg wire so might as well have a go at rewinding it.
Any ideas how many winds it will need?
I was hoping to try unravel the original wire to get an approximate length but it was partially covered in some resin or goop.
The mount and cover are in good condition though.
Took a while to prize it out.
Stickman393
Well-known member
Honestly: my recommendation would be to take that 38awg you have and...very...carefully...under a magnifying glass with a fine tip....try to extend the ends of the wire.
Its definitely doable. If you can pull it off, it'll be wayyyy easier than re-winding the core. Just be very careful, don't touch the rest of the wires coming off the core with the soldering iron: this is enamel or polymer-coated "magnet" wire...super thinly insulated and very easy to burn through with a soldering iron. If you burn through the insulation on the windings, you'll probably create a short.
Don't worry if you have to undo a wrap or two to do this: thats not gonna make a huge difference at the end of the day. Once you have it extended, you may want to throw dab a little flexible glue on top of the joint you made to re-insulate the wires. Run that to a post, wrap the wire around the post a few times, solder the wire to the post, and you should be good to go.
If you have to re-wind: this is what you'll need to do.
Measure the wire Dunlop used with a pair of high-quality calipers. Find a magnet wire with that same diameter. Then, un-wind the toroid by hand, and count the wraps as you do so. This will be tedious, but it's necessary.
Then, measure the length of the wire you unwrapped, cut a legth of your magnet wire that is about 12" longer.
Then, re-wind the toroid by hand. Leave 6" of excess hanging loose when you start winding (this will eventually be soldered to a post and is the "start" of your inductor) Try to keep constant tension on the windings (not so tight that you break the wire, but it should hug the ferrite core), and try not to overlap windings. Keep relatively even spacing between the windings.
You'll need to do keep count as you wind, and you'll need to wrap the wire the same number of times that you counted when you un-wrapped. You should have another 6" left when you finish. That'll be your "end" and it'll get wrapped and soldered to a second post.
Its definitely doable. If you can pull it off, it'll be wayyyy easier than re-winding the core. Just be very careful, don't touch the rest of the wires coming off the core with the soldering iron: this is enamel or polymer-coated "magnet" wire...super thinly insulated and very easy to burn through with a soldering iron. If you burn through the insulation on the windings, you'll probably create a short.
Don't worry if you have to undo a wrap or two to do this: thats not gonna make a huge difference at the end of the day. Once you have it extended, you may want to throw dab a little flexible glue on top of the joint you made to re-insulate the wires. Run that to a post, wrap the wire around the post a few times, solder the wire to the post, and you should be good to go.
If you have to re-wind: this is what you'll need to do.
Measure the wire Dunlop used with a pair of high-quality calipers. Find a magnet wire with that same diameter. Then, un-wind the toroid by hand, and count the wraps as you do so. This will be tedious, but it's necessary.
Then, measure the length of the wire you unwrapped, cut a legth of your magnet wire that is about 12" longer.
Then, re-wind the toroid by hand. Leave 6" of excess hanging loose when you start winding (this will eventually be soldered to a post and is the "start" of your inductor) Try to keep constant tension on the windings (not so tight that you break the wire, but it should hug the ferrite core), and try not to overlap windings. Keep relatively even spacing between the windings.
You'll need to do keep count as you wind, and you'll need to wrap the wire the same number of times that you counted when you un-wrapped. You should have another 6" left when you finish. That'll be your "end" and it'll get wrapped and soldered to a second post.
Stickman393
Well-known member
Another update:
Holy hell.
Just got a pound of some very, very fine Litz wire in the mail from John @ https://kc9on.com/.
Good dude, cool store, recommended!
I'm in the process of printing up a spool holder for this thing: after that, I'll be winding, assembling, and testing a few 1811Ps.
Do I expect a difference? Fucked if I know. I'm just doing this cause the Friedman Wah used Litz wire in their 1811P, and I wanted to experiment.
Holy hell.
Just got a pound of some very, very fine Litz wire in the mail from John @ https://kc9on.com/.
Good dude, cool store, recommended!
I'm in the process of printing up a spool holder for this thing: after that, I'll be winding, assembling, and testing a few 1811Ps.
Do I expect a difference? Fucked if I know. I'm just doing this cause the Friedman Wah used Litz wire in their 1811P, and I wanted to experiment.
Thanks for the info!
Unfortunately, i damaged the windings removing the toroid - the gloop that secured it was doing a fantastic job holding it in the pot cover so the windings were damaged while i scraped away at it to remove the epoxy or whatever it was.
That said there wasnt a great deal wrapped around it from what i could see so i guess the only option now would be to trial and error using lengths of the pickup wire and measure it then.
Now, i’ve found these toroid mounts - VTM620-2 which are very similar in size to the fasel and the fasel toroid (unwound) sits quite nicely inside, with a clip-on cover to the rear.
Pin spacing is the same, except to mount it upright to a pcb the pins need bending.
Unfortunately, i damaged the windings removing the toroid - the gloop that secured it was doing a fantastic job holding it in the pot cover so the windings were damaged while i scraped away at it to remove the epoxy or whatever it was.
That said there wasnt a great deal wrapped around it from what i could see so i guess the only option now would be to trial and error using lengths of the pickup wire and measure it then.
Now, i’ve found these toroid mounts - VTM620-2 which are very similar in size to the fasel and the fasel toroid (unwound) sits quite nicely inside, with a clip-on cover to the rear.
Pin spacing is the same, except to mount it upright to a pcb the pins need bending.
