Short Review of US Coils
Background
I have quite a complex crossover network I am putting together.
I had some specific DCR requirements that had to be met.
A couple of members recommended US COILS. They have lots of different types of coils in all difference wire gauages so suit your needs.
Types
I ordered a variety of inductors to suit my needs. Most of these are their EQ air coils which they tout as "perfect lay". One of them is the XQ if I remember correctly. The iron core are their IQX.
Review
The good: The iron core inductors look very nice
The bad: These are by far the ugliest brand new inductors I have ever seen. The winding looks like crap. I planned to put this crossover on my wall but might hide it under my desk now. I have used super cheap inductors in professional builds that look 10x better than this. I will post up the pictures.
I am quite dissappointed in the quality. I will be testing the inductance of these in the next few days at our lab. If they measure out dead on I will forgive the aesthetics but I am not seeing how an inductor wound this way is going to measure out properly.
I will post up with measurements when I have them.
Let me know your experience with US Coils. Did your inductors look like this?
Background
I have quite a complex crossover network I am putting together.
I had some specific DCR requirements that had to be met.
A couple of members recommended US COILS. They have lots of different types of coils in all difference wire gauages so suit your needs.
Types
I ordered a variety of inductors to suit my needs. Most of these are their EQ air coils which they tout as "perfect lay". One of them is the XQ if I remember correctly. The iron core are their IQX.
Review
The good: The iron core inductors look very nice
The bad: These are by far the ugliest brand new inductors I have ever seen. The winding looks like crap. I planned to put this crossover on my wall but might hide it under my desk now. I have used super cheap inductors in professional builds that look 10x better than this. I will post up the pictures.
I am quite dissappointed in the quality. I will be testing the inductance of these in the next few days at our lab. If they measure out dead on I will forgive the aesthetics but I am not seeing how an inductor wound this way is going to measure out properly.
I will post up with measurements when I have them.
Let me know your experience with US Coils. Did your inductors look like this?
Attachments
They don't look as nicely wound as the stuff I get from parts express, but I would imagine that most people are not expecting to see them so it shouldn't matter unless they measure inconsistently. I'm interested in your results because I have nearly ordered from them a few times. If you don't mind, please let me know if they measure accurate to spec and consistently. I would loathe getting two coils that are supposed to be identical but have different DCR or mH.
I dunno, they look like speaker crossover inductors to me. Not quite as nice as Solen Perfect Lay, about the same as Madisound house branded. If I were to design crossovers for display, would probably spring for Jantzen Cross Coils or Litz wire coils. Now, you want some UGLY inductors, you should see my tapped inductors that I purchased years ago from North Creek. Fugly! But, they test dead on and are great for prototyping.
Dan
Dan
Will do. I'll grab the LCR meter from the lab and run it tomorrow. As I said, I can forgive the looks if they measure properly.
You can always wind your own...
Oh, and this is blue enamel, not one of the common 4 colors; natural, brown, red, and green.
Oh, and this is blue enamel, not one of the common 4 colors; natural, brown, red, and green.
Had I known they were going to look like this, I would have. I considered it but decided to be lazy.You can always wind your own...
Next time, I'll engineer up a 3d printable winding jig and use one of the random motors I have laying around to power it
Hello
Agree I have seen better cosmetics as other have said from the same sources. As long as they meet your tolerances for DCR and Inductance it should be fine. Then be glad you have a source you can depend on to suite your needs
Rob 🙂
Agree I have seen better cosmetics as other have said from the same sources. As long as they meet your tolerances for DCR and Inductance it should be fine. Then be glad you have a source you can depend on to suite your needs
Rob 🙂
What are you using to wind it? I'm thinking a straight drive motor then a guide eye on a worm gear to move the guide back and forth
Somewhere in my old textbooks is the formula for making one of these
I'd ship ya one of mine but they weigh a ton. I have 6 little motors left over from a project. They have a ton of torque and would wind a coil like a child could wind a ball of yarn
If you like, send them to me and I will run 'em through my Bode-100 Vector Network Analyzer. Get all the specs.
I have measurements.
Long story short:
They measure really well. The worst I saw was off by 2%. Most are within 0.5-1%. This is amazing for an inductor.
However, my LCR meter also reads DCR. I ran this on the secondary but didn't have time to run it on the primary measurements. I read double what is stated on the US Coils site. The iron core were like 50% more. Not great. Then again, I have never taken a DCR measurement and I ran it at 1000hz so I don't know what the standard is. This could very likely be bad data.
I can forgive the ugliness to have inductors within 0.5-2% tolerance
I also took some measurements of resistors and caps. All of those were within 1-2%. Resistors were basically dead on.
I had a 200uf electro so I ran that too. Off by 5uf at 100 hz. Dead on at 100 hz. I suppose this is why people use them in the woofer circuit and not the highs.
A benefit to all of this is that I had 4 of certain components. I can match them and split them into pairs. Make sure I use one high measuring component and one low measuring component in either side. This reduces the differences between the two sides which should help with staging and imaging at least a little bit. I don't see a reason not to do this.
Lastly, I have A TON of wire in my shop. We do machines, automation equipment, military weapons, robots, if it has electricity then we build the prototype of it. I have very fancy test lead wire. Fine strand, tin plated, designed for multimeters. I have all kinds of wire. I measured the fancy stuff and I measured the cheap stuff. I won't post all the results but the cheap MTW wire I buy from Southwire measured the best. It is straight copper. It has the lowest resistance and lowest inductance of the whole lot. Strange, but I won't ignore data. MTW wire it is from now on.
Long story short:
They measure really well. The worst I saw was off by 2%. Most are within 0.5-1%. This is amazing for an inductor.
However, my LCR meter also reads DCR. I ran this on the secondary but didn't have time to run it on the primary measurements. I read double what is stated on the US Coils site. The iron core were like 50% more. Not great. Then again, I have never taken a DCR measurement and I ran it at 1000hz so I don't know what the standard is. This could very likely be bad data.
I can forgive the ugliness to have inductors within 0.5-2% tolerance
I also took some measurements of resistors and caps. All of those were within 1-2%. Resistors were basically dead on.
I had a 200uf electro so I ran that too. Off by 5uf at 100 hz. Dead on at 100 hz. I suppose this is why people use them in the woofer circuit and not the highs.
A benefit to all of this is that I had 4 of certain components. I can match them and split them into pairs. Make sure I use one high measuring component and one low measuring component in either side. This reduces the differences between the two sides which should help with staging and imaging at least a little bit. I don't see a reason not to do this.
Lastly, I have A TON of wire in my shop. We do machines, automation equipment, military weapons, robots, if it has electricity then we build the prototype of it. I have very fancy test lead wire. Fine strand, tin plated, designed for multimeters. I have all kinds of wire. I measured the fancy stuff and I measured the cheap stuff. I won't post all the results but the cheap MTW wire I buy from Southwire measured the best. It is straight copper. It has the lowest resistance and lowest inductance of the whole lot. Strange, but I won't ignore data. MTW wire it is from now on.
Attachments
Jantzen Audio says this on their website:
"For air cored inductors it does not matter what voltage and frequency parameters you use to measure a coil.
For ferro-magnetic cored coils we recommend using the audio industry standard of measuring at 1 volt / 1 kHz."
You might check if your LCR meter was set to 1V rather than .6V or .3V.
Art
English is not my first language so maybe I just don't get it. But are you saying that you are doing a DCR measurement at 1kHz? That doesn't work. It's either DCR or impedance at 1kHz which will be the same with a non inductive resistor but differ with an inductor.
Official data on inductor dcr are accurate, and you can't rely on dcr values measured with LCR meter.
Basic multimeter will confirm it. 1mH coil has about 24m of 16 awg wire. 1 m reads 0.013R.