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Celeste iv rebuild

 
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Ripcurler
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Joined: 06 Sep 2016
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PostPosted: Sat Sep 17, 2016 4:55 pm    Post subject: Celeste iv rebuild Reply with quote

I'm hoping someone can help me. I have a pristine pair of Celeste iv except the voice coils on both tweeters are open circuit. Careful disassembly and inspection with a loupe shows that the wire is broken on the voice coil itself. The tweeters look identical to the t33-a sp1074 but have a plain white kef label with the numbers 2782. I can't find any info on these anywhere. Assuming that they are the t33 - are replacements diaphragms still available?
If not would the Audax TW025A0 (is there a better match) disassemble and fit the original faceplate?

Any help would be greatly appreciated
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speakerguru
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PostPosted: Sun Sep 18, 2016 5:44 pm    Post subject: Reply with quote

I'm pretty sure the first cloth sock covered Celeste and Concorde (III?) offerings from KEF used the Audax 1" soft dome tweeter. It proved to be unreliable, often going open circuit. I seem to recall the Celeste and Concorde IV used a Panasonic tweeter instead.
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Ripcurler
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PostPosted: Sun Sep 18, 2016 6:03 pm    Post subject: Reply with quote

Do you mean that the tweeters were built by audax to the kef design? I have taken some photos of the tweeters - they look very much like the t33 sp1074. I think the audax had a circular front panel

Last edited by Ripcurler on Tue Sep 20, 2016 7:13 pm; edited 1 time in total
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speakerguru
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PostPosted: Tue Sep 20, 2016 9:47 am    Post subject: Reply with quote

Your link just takes me to the Photo Box front page, not your album, so I can't see the pictures. Do I need to have an account to view?
Anyway, I meant the regular round plate Audax. I did not remember KEF having started out using T33s in that model but I'll take your word for it.

History: the Celeste had to be built to hit the 100/pair price point in the shops. This meant buying in the tweeters, having a paper cone B200s made to KEF spec by ELAC (then in North London) and not having veneered cabinets.
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audiolabtower
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PostPosted: Tue Sep 20, 2016 10:27 am    Post subject: Reply with quote

https://www.photobox.co.uk/album/4417045026

is the reconstructed link, but I still can't expand the pics for a closer look.
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Ripcurler
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PostPosted: Tue Sep 20, 2016 7:10 pm    Post subject: Reply with quote

Sorry about the link. I have created a photobucket account so hopefully that will be better.... new link below

http://s38.photobucket.com/user/stuartnwatson/library/KEF%20T33
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Ripcurler
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PostPosted: Tue Sep 20, 2016 7:26 pm    Post subject: Reply with quote

The B200 bass drivers are the paper coned SP1070, three point fixings and mechanically isolated from the sealed cabinet. Here is a picture of the bass driver http://s38.photobucket.com/user/stuartnwatson/library/B200%20SP1070
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speakerguru
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PostPosted: Wed Sep 21, 2016 8:42 am    Post subject: Reply with quote

Photobucket links work.

That is a KEF T33; probably the SP1074 8 Ohm nominal impedance, 6.6 Ohms d.c. resistance. I'm beginning to forget SP numbers!

Sorry I can help with XO component values. You definitely need to replace the electrolytic capacitors which should all be bipolar types.
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Ripcurler
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PostPosted: Mon Oct 03, 2016 9:03 pm    Post subject: Reply with quote

The voice coils in these T33s are not fluid cooled. The new diaphragms have arrived - would you advise using ferro fluid in the rebuild?
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speakerguru
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PostPosted: Wed Oct 05, 2016 7:46 am    Post subject: Reply with quote

Ripcurler wrote:
The voice coils in these T33s are not fluid cooled. The new diaphragms have arrived - would you advise using ferro fluid in the rebuild?

in theory yes, but check with the supplier that the adhesives used in the vc assemblies is compatible with the ferrofluid.
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