Wah Inductors. No hype. Just measurements.
- Thread starter Stickman393
- Start date
Stickman393
Well-known member
That's generally been the case with stock mounts for me too; I've collected a few that work well in certain situations, but for the most part moving forward I'll be making mine with custom mounts.
The mounts for these, especially the pot cores, can get real pricy real quick. I'm having to get creative with the way I do my own.
I've just completed winding three new cores with my new roll of Litz wire. I gotta say...it's much easier to work with than the stuff I was using before. More flexible, less likely to break. Its thicker, so it lays down easier, but I'm still getting like 40 ohms from a completed nominal 525mH coil.
The experiment here was to track my progress in programming the coil winder. #1 was *way* off and resulted in a coil that was heavily scatter wound. So....lemonade, bitches. #2 was less scatter wound, #3 had minimal to no scatter winds.
I'll be assembling them today and doing a comparison. There are still variables here that I can't quite account for: clamping force is still a beyond my current abilities to measure, and there will be some natural variation in the cores. But, in theory, scatter winding will have two impacts: a decrease in parasitic capacitance, and a decrease in inductance.
Will I be able to observe that? Dunno. Too many unaccounted for variables. Plus, I'm just a guitar player banging rocks together. Who is also a literal stick man.
The mounts for these, especially the pot cores, can get real pricy real quick. I'm having to get creative with the way I do my own.
I've just completed winding three new cores with my new roll of Litz wire. I gotta say...it's much easier to work with than the stuff I was using before. More flexible, less likely to break. Its thicker, so it lays down easier, but I'm still getting like 40 ohms from a completed nominal 525mH coil.
The experiment here was to track my progress in programming the coil winder. #1 was *way* off and resulted in a coil that was heavily scatter wound. So....lemonade, bitches. #2 was less scatter wound, #3 had minimal to no scatter winds.
I'll be assembling them today and doing a comparison. There are still variables here that I can't quite account for: clamping force is still a beyond my current abilities to measure, and there will be some natural variation in the cores. But, in theory, scatter winding will have two impacts: a decrease in parasitic capacitance, and a decrease in inductance.
Will I be able to observe that? Dunno. Too many unaccounted for variables. Plus, I'm just a guitar player banging rocks together. Who is also a literal stick man.
So, will a thicker wire need less winds to get it to the required mh?
For example, i found one online tutorial to build an inductor using a wah inductor kit (pot core n48, bobbin etc) using 38awg wire and it needed about 500 winds approx to get to around 500mh.
Would thicker wire need less winds or more?
Stickman393
Well-known member
In my experience...well, it all depends.
Inductance is proportional to the square of the number of turns. This is how I've made small adjustments while winding my own cores, but there are other factors to consider as well.
The clamping pressure with which the cores are held together will impact your final measured value. How well the cores align will also have a huge impact.
I believe the ferrite variety that they sell with those kits is the N48. If that's the case, 500 winds is probably about right. Doesn't matter if it's 38, 40, etc.
But...in my experience, the way the core is wound also matters. Several factors interplay here: scatter winding appears to lead to a core with a lower Q and decreased inductance (though...hard to say on that last bit, as these cores tend to have about a 20% tolerance, and the differences I've observed are well within that range). Which makes sense: scatter winding positions the wraps further away from each other, where their individual magnetic fields don't have as much strength.
But...in the case of perfectly straight and aligned coils: having those wires in close proximity to each other also means that their individual electrical fields will have a greater impact between winds, creating parasitic capacitance, which also shows up as a lower measured inductance value. But I've found this to impact the end result less than scatter winding.
Thinner wire will have more resistance over its length. My favorite inductors have had DCR values of around 30-60 ohms...toroids tend to be around the 10-20 range in my experience.
Resistance will influence Q. Greater resistance=lower Q, and vice versa. Some manufacturers will put resistors in series with the inductor to bring down Q...this is the case with the Ernie ball wah, a pedal that absolutely did not need its Q to be tamed. This is also how the 535Q controls Q.
Now...you might be thinking...wait! Isn't the Increasing "vocal mod" performed by increasing resistance?
Well...sure. But that's a parallel path around the inductor. Increase the resistance there, and you force more current through the inductors path. Resistors don't really have a Q factor: they can only influence the Q factor of reactive components like inductors or capacitors.
Granted, treat the above information for what it is: the musings of a dude who is performing extremely unscientific experiments and barely understanding the stuff that he reads about those things that an electrician once told me he didn't believe in. Ahhhh...oh! Electrons. That's right.
Inductance is proportional to the square of the number of turns. This is how I've made small adjustments while winding my own cores, but there are other factors to consider as well.
The clamping pressure with which the cores are held together will impact your final measured value. How well the cores align will also have a huge impact.
I believe the ferrite variety that they sell with those kits is the N48. If that's the case, 500 winds is probably about right. Doesn't matter if it's 38, 40, etc.
But...in my experience, the way the core is wound also matters. Several factors interplay here: scatter winding appears to lead to a core with a lower Q and decreased inductance (though...hard to say on that last bit, as these cores tend to have about a 20% tolerance, and the differences I've observed are well within that range). Which makes sense: scatter winding positions the wraps further away from each other, where their individual magnetic fields don't have as much strength.
But...in the case of perfectly straight and aligned coils: having those wires in close proximity to each other also means that their individual electrical fields will have a greater impact between winds, creating parasitic capacitance, which also shows up as a lower measured inductance value. But I've found this to impact the end result less than scatter winding.
Thinner wire will have more resistance over its length. My favorite inductors have had DCR values of around 30-60 ohms...toroids tend to be around the 10-20 range in my experience.
Resistance will influence Q. Greater resistance=lower Q, and vice versa. Some manufacturers will put resistors in series with the inductor to bring down Q...this is the case with the Ernie ball wah, a pedal that absolutely did not need its Q to be tamed. This is also how the 535Q controls Q.
Now...you might be thinking...wait! Isn't the Increasing "vocal mod" performed by increasing resistance?
Well...sure. But that's a parallel path around the inductor. Increase the resistance there, and you force more current through the inductors path. Resistors don't really have a Q factor: they can only influence the Q factor of reactive components like inductors or capacitors.
Granted, treat the above information for what it is: the musings of a dude who is performing extremely unscientific experiments and barely understanding the stuff that he reads about those things that an electrician once told me he didn't believe in. Ahhhh...oh! Electrons. That's right.
Stickman393
Well-known member
Also: I'd say that yellow fasel is absolutely salvageable. Just need to get a bit of magnet wire, twist the end together with the one there, solder, insulate (nylon/kapton/polyamide tape is nice and thin and would do the trick), then wrap around the post, solder, and you're good.
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