hi guys
although i have wound the inductors for my xt25/pl18 project myself with some nice thick enamelled copper from wires.co.uk, i am about to embark on a 3 way floorstander for my dad which has a quite complicated crossover (the sp38 from troels gravesen, am waiting for him to finish and fine tune them and report back on his website, they look as if they should be really good) and really dont fancy winding all the inductors myself.
I was wondering where all the UK based diy'ers get their air cored inductors from? the ones i have found seem to have a dc resisitance that is was to high.
cheers,
matt.
although i have wound the inductors for my xt25/pl18 project myself with some nice thick enamelled copper from wires.co.uk, i am about to embark on a 3 way floorstander for my dad which has a quite complicated crossover (the sp38 from troels gravesen, am waiting for him to finish and fine tune them and report back on his website, they look as if they should be really good) and really dont fancy winding all the inductors myself.
I was wondering where all the UK based diy'ers get their air cored inductors from? the ones i have found seem to have a dc resisitance that is was to high.
cheers,
matt.
Naff all selection in the UK I'm afraid.
Sure you can get air cored from places like Wilmslow, Falcon and a few others but they are merly adequate.
Personally, and when the project calls for it, I import Goertz/Alphacore Copper foil inductors from Speakercity in the US. Or sometimes from Solen. Not cheap but certainly better than the stuff over here.
Sure you can get air cored from places like Wilmslow, Falcon and a few others but they are merly adequate.
Personally, and when the project calls for it, I import Goertz/Alphacore Copper foil inductors from Speakercity in the US. Or sometimes from Solen. Not cheap but certainly better than the stuff over here.
hi again- looks like the sp38 3 way speaker from troels gravesen may well be going ahead, but still no luck on finding decent inductors over here.
I see so many members with a little union jack under their nick on these boards- surely some of you must have bought inductors from somewhere over here?
cheers again, matt w.
I see so many members with a little union jack under their nick on these boards- surely some of you must have bought inductors from somewhere over here?
cheers again, matt w.
Puggie, thanks for that resin tip. What causes buzzing?
I just roll mine up on an aluminum can, slip the cable ties on after the desired # of turns, then crush the can to get it off. Plastic bottles work the same way for smaller diameters. It may be low tech but it seems to work well without being too time consuming.
I just roll mine up on an aluminum can, slip the cable ties on after the desired # of turns, then crush the can to get it off. Plastic bottles work the same way for smaller diameters. It may be low tech but it seems to work well without being too time consuming.
yeah i have used a simailar technique to wind the large inductors for my current project, and it absolutely killed my fingers! 
i used one of the online calculators to work out the number of turns, but am not 100% sure how accurate they are. Also i found it very hard to keep track of the number of turns on each inductor as i was winding them. mine are both the same size, and weigh the same amount so i assume they are pretty well matched. I cant hear any difference between the 2 speakers, although at the mo i am not in a position to do proper freqency sweeps and record results.
What is the best way of measuring them to make sure they are correct? put them in series with a cap of known value and find the resonant freqency?
are the values particularly critical to get 100% spot on?
comments appreciated.
i used one of the online calculators to work out the number of turns, but am not 100% sure how accurate they are. Also i found it very hard to keep track of the number of turns on each inductor as i was winding them. mine are both the same size, and weigh the same amount so i assume they are pretty well matched. I cant hear any difference between the 2 speakers, although at the mo i am not in a position to do proper freqency sweeps and record results.
What is the best way of measuring them to make sure they are correct? put them in series with a cap of known value and find the resonant freqency?
are the values particularly critical to get 100% spot on?
comments appreciated.
no, they havent ben measured yet due to they project being put on hold for a few months while i finish off uni, the amount of coursework i have at the moment is rediculous. But the crossovers are in a separate box at the bottom of my hifi rack so i can get at the components very easily- being my first project i knew they would probably need tweaking. The speakers are nowhere near being finished, and both need painting too.
what is a decent LCR meter and how much £ am i looking at? I have looked on the CPC website, the ones they have dont seem to be very accurate.
the potential divider method seems pretty simple, ill try it when im back at home.
cheers.
what is a decent LCR meter and how much £ am i looking at? I have looked on the CPC website, the ones they have dont seem to be very accurate.
the potential divider method seems pretty simple, ill try it when im back at home.
cheers.
Buzzing is caused because a coil with current passing through it is akin to an electromagnet, with AC you are re magnetizing it alternate ways regularly, the magnetism causes toe coils to attract and not attract eachother which can cause movement and noise (not a lot mind but if you ever notice it, it will annoy the hell out of you!). Fibreglassing resin just holds them all together nicely.
Same probs here, nothing outside Falcon and Wilmslow. I was fortunate enough to pick up some decent copper foil inductors trawling through the tiny markets in Tokyo last year, but that's not exactly a regular opportunity!
I would echo the earlier advice of using a US source (also look at PartsExpress and Madisound). While searching for a supplier of Mundorf M-Cap Supremes I came across this German supplier who also do foil and other inductors. Prices seem pretty good and for small quantities should work out cheaper overall with the lower postage costs. Sure, the site's all in German, but when I emailed them I got a very helpful reply in english. I didn't order through them in the end as I couldn't justify buying the Mundorfs, however it's nice to know of these alternate suppliers.
Another useful international supplier is Leda Resources based in Singapore, they have a rather bespoke selection of goodies.
The lack of an LCR meter, and the cash to buy one, has kept me away from winding my own. That and the headaches trying to convert inductance equations into something that would work out bobbin diameters for perfect-lay inductors (4:1:1 basically). Without the LCR I'd never be able to check if my equations had worked! I think they cost upwards of about £60, but I haven't looked in a few years. Despite knowing that speaker building will be a lifelong addiction, I'm perfectly happy to work up a crossover with some cheapy coils then order a nice low DCR foil-coil (hmmm, wonder if I can patent that) from across the water.
I would echo the earlier advice of using a US source (also look at PartsExpress and Madisound). While searching for a supplier of Mundorf M-Cap Supremes I came across this German supplier who also do foil and other inductors. Prices seem pretty good and for small quantities should work out cheaper overall with the lower postage costs. Sure, the site's all in German, but when I emailed them I got a very helpful reply in english.
I didn't order through them in the end as I couldn't justify buying the Mundorfs, however it's nice to know of these alternate suppliers.Another useful international supplier is Leda Resources based in Singapore, they have a rather bespoke selection of goodies.
The lack of an LCR meter, and the cash to buy one, has kept me away from winding my own. That and the headaches trying to convert inductance equations into something that would work out bobbin diameters for perfect-lay inductors (4:1:1 basically). Without the LCR I'd never be able to check if my equations had worked! I think they cost upwards of about £60, but I haven't looked in a few years. Despite knowing that speaker building will be a lifelong addiction, I'm perfectly happy to work up a crossover with some cheapy coils then order a nice low DCR foil-coil (hmmm, wonder if I can patent that
) from across the water.Hi folks, the best source of inductors in the UK is probably audiocom. They stock the Intertechnik range, which includes aircore and irondust core that I've used myself (and found very decent) and also I think some litz wound and foil jobbies that I would use if I was more loaded. Try www.audiocom-uk.com.
I would agree the wilmslow range of coils is an utter joke.
HTH.
I would agree the wilmslow range of coils is an utter joke.
HTH.
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.