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C55 SP2134

 
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polskajay
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Joined: 01 May 2014
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PostPosted: Thu May 01, 2014 10:36 pm    Post subject: C55 SP2134 Reply with quote

I picked up 2 pair of working C55s from local craigslist for under $100 (for BOTH pair). I'm reasonably handy with a soldering iron and decided I was going to upgrade the caps with nice Dayton caps and see if I could tell much diff between the pairs. Unfortunately, I messed up the PCB board and it won't conduct to the tweeter. So I bought a perforated board from RS and was going to rebuild it with new caps. Despite exhaustive searches, multiple search terms, I cannot, CANNOT, find any info on this crossover. Not whether it's 2nd, 3rd order... and definitely NOT a schematic. I am unfamiliar with the PCB and tried unsuccessfully to break it down. Can anyone help? Schematic would be amazing or even a resource. And, I DID write KEF twice and have gotten NO response. Thanks very much in advance AND thanks for letting me be a part of the forum. Jay
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proffski
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PostPosted: Fri May 02, 2014 8:09 am    Post subject: Re: C55 SP2134 Reply with quote

I cannot imagine the crossover being all that complicated.
Have you considered looking at the board in the other loudspeker and tracing that? It should be simple enough...
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speakerguru
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PostPosted: Sat May 03, 2014 10:00 am    Post subject: Re: C55 SP2134 Reply with quote

polskajay wrote:
I'm reasonably handy with a soldering iron .... Unfortunately, I messed up the PCB board and it won't conduct to the tweeter...


Clearly not handy enough Wink. Like proffski says look at the other one, trace and copy it....or did you not tell the whole story? Did you mess up both and there is no other one to look at?
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polskajay
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PostPosted: Sat Oct 11, 2014 10:56 pm    Post subject: sp2134 Reply with quote

No, only one is messed up. As the message says, I am NOT familiar with PCB boards and attempted to trace it out unsuccessfully. Additionally, I'm NOT an electrical engineer. I tried using my meter to trace continuity but have read various things regarding continuity and capacitors (as in, you can't?). Here are pics of the crossover. If you can help, I'd be very grateful. If you're just going to post more useless crap, please do as your mom taught you and don't say anything (if you can't say anything nice). It seems reasonably obvious that if I could simply trace it, I would have. I have photos of the front and back of the intact crossover.
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proffski
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PostPosted: Sat Oct 11, 2014 11:02 pm    Post subject: Re: KEF SP2134 Reply with quote

That was uncalled for, have you been drinking? I think an apology to SpeakerGuru is forthcoming.
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Last edited by proffski on Sun Oct 12, 2014 1:48 pm; edited 1 time in total
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polskajay
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PostPosted: Sat Oct 11, 2014 11:33 pm    Post subject: 2134 Reply with quote

No, actually it was completely called for. And I don't drink. I simply asked for help. I admitted what I don't know. Instead of ANY of you helping, you mocked me. Your forum has been about as useful as the complete lack of response from KEF has been.

I don't do this for a living. I simply tinker with old equipment and I'm new at that! Forgive me for trying to learn something from those with more knowledge than me. And, yes I agree that this forum isn't the place for arguments so I'll go back to wondering what the use of joining it was. Thanks for nothing. Peace.
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proffski
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PostPosted: Sat Oct 11, 2014 11:42 pm    Post subject: Re: 2134 Reply with quote

We are all more than happy to help each other here, always allowing some leeway for misunderstandings. Which may have ocured here, sadly your attitude has made me put the barriers up.
I'm not proud of this, but aggression is something not welcome here. I'll retain all forthcoming help and advice till an apology materialises. Matter closed, good luck with your classic transducers.
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willem-57
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PostPosted: Sun Oct 12, 2014 10:20 am    Post subject: Reply with quote

strange guy! Shocked

Last edited by willem-57 on Mon Oct 13, 2014 7:55 am; edited 1 time in total
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proffski
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PostPosted: Sun Oct 12, 2014 11:30 am    Post subject: Reply with quote

Confused
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audiolabtower
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PostPosted: Sun Oct 12, 2014 12:57 pm    Post subject: Reply with quote

Mr Jay, in the words of the proverbial Liverpudlians... Calm down! Calm down!

The C55 was a passive radiator, so the crossover was just between the woofer and uniQ tweeter. I found somewhat of a pic here
http://www.audiokarma.org/forums/attachment.php?attachmentid=144716&d=1238894939

Don't know anything about them but shall guess a lot. If you assume a 3rd order crossover to the tweeter there should be 2 smaller capacitors in series from the input to the tweeter, and the junction between them a small inductor to ground. There may also be a small value resistor in there somewhere in series to equalise the levels.

If we assume a 2nd order crossover to the woofer, a larger inductor in series to the woofer with a larger capacitor to ground. If the bass section is a 3rd order, then a second large inductor in series, it looks like there are 2 large inductors with tie wraps around them? If there are any more small components they might be a resistor capacitor series connected across one or both of the drive units to help simplify the design, but it doesn't look as if there enough solder pads for many more bits. SpeakerGuru might know if an "aB" section was used for the tweeter by this time, which would complicate the capacitors around the tweeter section somewhat.
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proffski
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PostPosted: Sun Oct 12, 2014 1:39 pm    Post subject: Reply with quote

Agreed, another picture here: http://i178.photobucket.com/albums/w266/halo71/download20110104009.jpg

And here: http://www.audiovintage.fr/leforum/download/file.php?id=9756
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Last edited by proffski on Sun Oct 12, 2014 1:59 pm; edited 1 time in total
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audiolabtower
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PostPosted: Sun Oct 12, 2014 7:20 pm    Post subject: Reply with quote

Good find, Prof, there are more tie wraps to see there - maybe 4 inductors?
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proffski
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PostPosted: Sun Oct 12, 2014 7:23 pm    Post subject: Reply with quote

Tricky, you could well be right. Shame nobody as yet has chosen to photograph and publish the component side!
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willem-57
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PostPosted: Mon Oct 13, 2014 7:38 am    Post subject: Reply with quote

Found one, i think, from old ebay ad. Sadly it's very small.
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