That voice coil looks cooked... all that discolouration is where it got HOT. Voice coils are usually an even number of layers so it gets wound from top to bottom and back again.
dave
dave
jkeny said:
Somewhere, be it a peripheral ring where you see the discoloration or evenly changing that gap just so, it has expanded for sure. Hence the rub.
Oh, I agree salas,
That'swhy I can't use the coils as-is but will have to unwind (carefully) and rewind (carefully) onto new former.
Any sources for Nomex former? (I think I'll put this as my signature for a while)
That'swhy I can't use the coils as-is but will have to unwind (carefully) and rewind (carefully) onto new former.
Any sources for Nomex former? (I think I'll put this as my signature for a while)
China is where they get em now days. They normally get many different standard cylinder sizes, or completely wound coils on special volume orders.
That is for the speaker industry.
You can meet it in motor phase insulation and transformers. Do you know an electric motor or transformer guy nearby?
But there are bulk sources of raw aramid sheets, acrylics, too. You dont need that much. If you cant find a little from some constructor using it...
Just google for composites, nomex. Like
here
That is for the speaker industry.
You can meet it in motor phase insulation and transformers. Do you know an electric motor or transformer guy nearby?
But there are bulk sources of raw aramid sheets, acrylics, too. You dont need that much. If you cant find a little from some constructor using it...
Just google for composites, nomex. Like
here
BTW, I started a thread on this over at the LS3/5a Yahoo Groups forum & got some good advice also there - I haven't checked it yet but the coil might not have expanded but simply heated up & bubbled the former on the inside causing the rubbing.
If so the I could get away with lightly sanding the inside of the former to cure it. As my daughter would say "Happy Days"
http://tech.groups.yahoo.com/group/ls35a/message/21867
If so the I could get away with lightly sanding the inside of the former to cure it. As my daughter would say "Happy Days"
http://tech.groups.yahoo.com/group/ls35a/message/21867
Don't take the wrong way but it seems to me you're sinking deeper and deeper in dodoo. At this point paying the $700 and send them to a pro starts to look like a real deal to me. Actually you may need a genius artist more than a pro to put it back together in such a way it will produce sound anywhere near the original.
The bluish looking coil looks fried probably if you put it back it will heat up locally and bend, and after a while will start to rub again.
good luck!
The bluish looking coil looks fried probably if you put it back it will heat up locally and bend, and after a while will start to rub again.
good luck!
Thanks Salas,
Exactly my thinking!
Grataku,
Have you repaired/builtmany speakers? You didn't read the thread,I think - the coils test fine,no shorts! There also is no company that actually repairs these speakers now - RA technology has decommissioned their equipment for a relocation & will be 3 months before they're taking on new jobs. I wouldn't trust most general recone companies with this work so I'm doing it myself.
Exactly my thinking!
Grataku,
Have you repaired/builtmany speakers? You didn't read the thread,I think - the coils test fine,no shorts! There also is no company that actually repairs these speakers now - RA technology has decommissioned their equipment for a relocation & will be 3 months before they're taking on new jobs. I wouldn't trust most general recone companies with this work so I'm doing it myself.
It's amazing how people still love these LS3/5A speakers. I've met a few people here that just keep them forever.
Anyway, I have two B110 drivers in a DIY system that I haven't used for probably 20 years I guess. But I am also looking for a few hard to find Jordan drivers, the JX51, JX62, and an early version of the JX92. If you can find a pair of any of these that are in good condition, we could probably trade. The last time I saw a pair on Ebay, the would not deliver international.
Anyway, I have two B110 drivers in a DIY system that I haven't used for probably 20 years I guess. But I am also looking for a few hard to find Jordan drivers, the JX51, JX62, and an early version of the JX92. If you can find a pair of any of these that are in good condition, we could probably trade. The last time I saw a pair on Ebay, the would not deliver international.
Yep Soongsc,
Here's probably why - a friend built my JX92S drivers into a box design I chose & it turned out great, a little bigger than the Rogers boxes with great clarity & bass. From memory these sound not too dissimilar to the LS3/5As - great midrange & integration (they're single driver so no question here). Of course I would need the Rogers to A/B with to tease out the differences. So a 30+ year old speaker sounding (nearly?) as good as a modern aluminium cone driver is some achievement!
Why are you after an early version of the JX92 drivers as opposed to the existing model?
Here's probably why - a friend built my JX92S drivers into a box design I chose & it turned out great, a little bigger than the Rogers boxes with great clarity & bass. From memory these sound not too dissimilar to the LS3/5As - great midrange & integration (they're single driver so no question here). Of course I would need the Rogers to A/B with to tease out the differences. So a 30+ year old speaker sounding (nearly?) as good as a modern aluminium cone driver is some achievement!
Why are you after an early version of the JX92 drivers as opposed to the existing model?
Well, I already have the current JX92. I am interested in seeing how drivers like this evolve with time since these are designed by the same person devoted to metal cone drivers.
old thread , new experience
Well , finally after many moons passed I was able to borrow a pair of Rogers Ls3/5a (15 Ohms). I was convinced that I will be wasting time with them as I didn't like Harbeth line of speakers in audition at friendly dealer (monitor 40i and older 7th) I was wrong . I love those small boxes in my 10'x10 bedroom.I don't need anything better than this. What a nice pair of speakers!!
Regards, L
Well , finally after many moons passed I was able to borrow a pair of Rogers Ls3/5a (15 Ohms). I was convinced that I will be wasting time with them as I didn't like Harbeth line of speakers in audition at friendly dealer (monitor 40i and older 7th) I was wrong . I love those small boxes in my 10'x10 bedroom.I don't need anything better than this. What a nice pair of speakers!!
Regards, L
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Your room and placement is closer to what they were made for than a hi-fi showroom.😉 Happy listening. You got yourself a classic.
Yes, besides a bigger speaker cannot produce more bass in the small room ! I like the small harbeths and they deserve the best source and amp equipment possible.
I believe Kapton replaced Nomex as a voice coil former in the BBC LS5/8 because it can withstand a higher temperature, and Kapton tape is easily available.
I await your results with interest. I have a pair of LS3/5a, and although I'm not using them at the moment, I wouldn't dream of parting with them, not even for silly money. That must be why they go for silly money.
I await your results with interest. I have a pair of LS3/5a, and although I'm not using them at the moment, I wouldn't dream of parting with them, not even for silly money. That must be why they go for silly money.
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