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KEF 104aB B200 SP1039

I don't think any new B200 drivers would sound the same as the old ones which used Plastiflex (polyvinyl acetate) coated Bextrene (styrene-butadiene copolymer) as the cone material. The old B200s have a unique sound that new materials just don't reproduce.

I believe the surround material for the SP1054 used in the Calinda is Neoprene (polychloroprene). I didn't realize that the surround for the SP1039 used in the 104ab was PVC. Unfortunately PVC is more susceptible to degradation than Neoprene.
 
I would have agreed with you about the sound except Falcon has reproduced the B110, B139 and T27 already. It probably helps that the original designer of these drivers, Malcolm Jones who started Falcon is involved. The big question is which B200 will they make. I bet on the SP1039 since there were more of them and they are the ones in trouble. Presumably they'll go with a rubber surround this time.
 
Wow, you are right. I just checked their website. They are making the new B drivers out of coated Bextrene.
 
crdm6 said:
If the surrounds on the 1039 are degrading with time the chance of you finding an "as new" set is pretty low. Perhaps someone somewhere took some brand new ones and sealed them in a container with inert gas. Yeah right! How much would they want for them? Probably more than Falcon will ask.

The only issue with recapping (assuming you already know how to solder) is on some of the PCBs the tracks are huge and suck up the heat. You will need some real heat to do this not a wimpy 20 watt. If necessary you can put a metal clip on the cap lead as a heat sink.
Click to expand...

They are definitely out there. These 1039s all seem to be degrading at different rates with mine being somewhere mid-pack. I have seen some decent examples come up in the past year or two so I’m optimistic - and in no hurry.

Thanks for the soldering tips, I’m very inexperienced but am generally good with my hands. I have a choice of Weller guns - a friend’s 260/200 watt or my 140/100 watt. Pencil style would surely be easier to handle but this is what I have.
 
The thing about buying a used part that is known to fail is that you know it will fail as well.
In my previous life I told people that I could replace the dead video card in their iMac but I would have to use one from another iMac since Apple quit making them. All of them were failing, it was just a question of when. Also it was expensive because you had to disassemble the whole iMac to get to the video card because even though it was in a socket, the socket was on the back of the main board. Genius.

I've never seen the 104aB board but it's probably like my Calinda. They have almost the same circuit,
Out of your choice of guns, I'd say the 100 and be careful. I was thinking more along the lines of 40 to 60 watts. I also would say use some liquid flux when putting the new parts in. You can live without it but it does make for better joints. Last tip be sure to clean off the flux from the joints when you're done. Youtube is your friend for tutorials.

Pretty soon now I'll be doing this to my Reference 102s. More fun.
 
When did the b200’s become rare or expensive? I used to bin them when parting out speakers for the T27 B110 drivers to supply the silly market for ls3 clones. Nobody wanted the b200’s
 
You are in England. We are not.
The availability of ANY type of KEF drivers or systems is inversely proportional to one's distance from England.
To a lesser extent the same thing happens here in the States.
ARs and Rectilinears are common in Massachusetts not so much in Seattle. Likewise there aren't too many classic JBL boxes in New York. The only exception seems to be KLH stuff. It's everywhere.
Things are different now but we're talking 1970s speakers here.
If you have a pile of B200s taking up space, I'll pay the shipping. Send them over.
 
Oh yeah, the LS3/5a thing was crazy. They sound awesome in a broom closet or a BBC van. Not so great in a big American living room. The new thing seems to be a 6.5" or 5.25" woofer in bigger box so there's some bass but they do have volume limitations.
 
Dazaa said:
When did the b200’s become rare or expensive? I used to bin them when parting out speakers for the T27 B110 drivers to supply the silly market for ls3 clones. Nobody wanted the b200’s
Click to expand...
Not all B200 were created equal. Some can be found, others, not so easily. Do a google search for B200 sp1039 and see what you find.
 
The SP1014 variant is very easy to find. Not so the SP1039. I think the SP1022 (big magnet) is the rarest of them all.
All these are quite different drivers with the only common thing being the diameter. The cone material, coating, former material, coil material (copper/aluminum), overhang of coil on magnet gap and magnet size are quite different among these.
 
wow thats news to me, had no idea about the variants of the b200, only the b110. Have to start looking out for SP1039 and 22's now. Funny as just today I bought a pair of old british speakers with sp1039's in.
 
I realize that these may be difficult to obtain in the states. Overseas transport costs would obviously be involved and they would probably be similar to the price of the speakers themselves, if not higher, even.

My comment about availability was relating to availability, globally. Even in the UK, SP1022 are pretty rare and SP1039 don't come up often.
 
Well as Benjib and I have been discussing, the SP1039's have surround issues so there are less and less of them all the time.
They didn't make many SP1022's as its only official KEF model was the Cadenza.
In America in the 1970's probably the best known British speaker was the QUAD just because it was different.
KEFs were here but in very, very small numbers. KEF didn't really register with the public until the press discovered the LS3/5a.
Post #28 above sums up my thinking on LS3's. Meanwhile useful speakers like 104aBs, Calindas and Cantatas languished in obscurity.
 
I had a nice back and forth today via email with Jerry at Falcon. I’m feeling some of that good service I’d heard about. Jerry informed me the original 1039 PVC surrounds are not replaceable, as we suspected. I asked about the B200 variant they might have in development and turns out they are in the prototyping stage. He couldn’t confirm exactly which B200 will make it to market but that it would be a big magnet version, 1039 or 1022/1054.

My capacitors, coincidentally, arrived today so I’m planning the recap job for tomorrow. Got all my tools ready, watched a bunch of soldering videos and I’m feeling ready!
 
Yay! Go Go Go!
Once they're done you can enjoy them while you save your pennies for new B200's
 
Got the caps in. The job was pretty much what I expected. No snags along the way. Sitting comfortably listening now. Happy for the moment. Next job is these tired cabinets :)
 
What's the story on the SP1014 version a friend has a NOS pair?
Anyone have specs for all the variants?

Edit: Just remembered that I have a pair of SP1014 that are the small magnet used in KEF DIY kits.
 
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