PLEASE understand that this ad is for the REBUILD ONLY of the ferro fluid of a single KEF tweeter and not for the actual tweeters themselves. Pictures are for reference only! If you buy and expect tweeters, you will pay for the relist fees. Please understand.
The T33 was used in simply dozens of Kef speakers. Most notably the "1-oh" series. The 102, 103, 104, 105 and 107 series. many of the coda models, etc. NOTE!!!! If you own the T33A version (sp1074), tweeters in say the 103.2's you DO NOT need this service!!!! No fluid in that version.
After purchasing a pair of Meridian M30's and being disappointed in the sound I remembered as being more/less amazing in 1988, I began to research why. apparently the ferrofluid in the original kef T-33's notoriously dries out leaving all of these amazing tweets quite handicapped by today's standards. I began looking for replacements but realized quickly that most any NOS T33 was still the same age as mine and would certainly have ferrofluid in near as bad of condition. I have been an accomplished audio tech since around 1986 so I decided to research the potential repair of these tweeters. After obtaining the hard to find (and expensive) ferrofluid and diving in, I was able to very successfully remove the actual tweeter, its diaphragm, thoroughly clean the voice coil former, the magnet's gap, replace the ferrofulid, re-align, and successfully re-install the faceplate. The difference in sound was mind-boggling! The tweeters degrade so GRADUALLY over time you don't really notice until things are simply awful.
It is a tedious process but I have decided there must be hundreds of thousands of customers in need of this service given soooo many kef 33's in the field. Feel free to send them to me and they will return in amazing condition. I am still stunned at the difference it has made in my meridians.
I MUST be very, very clear that I do not repair blown or damaged diaphragms. This is strictly for those with T33's that just no longer have good midrange or overall volume and need new ferrofulid. All T-33's have this issue as all are well over 10 years old at this point. As of August of 2012 I found my first non-repairable tweeter sent to us. It was part of a pair and the mate was as easy as pie. The second tweet's voice coil former literally separated from its diaphragm due to either a bad adhesive job originally, slight overheating, or just a really bad hardening of the ferro fluid in its gap. Regardless, in these VERY rare instances I still must be clear that we cannot cover this issue. I trust you all understand. We have had a great number of you request a kit for reinstallation so we now have the 4 pcs. of heat shrink and appropriate amount of cardas silver/copper solder available for you guys upon request for $6 per kit. Just be sure and mention to me when ordering or add to your paypal payments, etc.
We now have a procedure for removal, shipping and reinstall available for you guys below.....
1-Removal. Most all T-33 types were provided by kef with their wires soldered directly on their terminals which makes for a bit of a challenge here. If you are proficient with soldering and de-soldering various audio terminals, you should be in good shape as we will simply be cutting the wires and re-soldering them together (unless you wish to be super anal retentive and demand to replace as original). If you do so, you do so at your own risk. The tiny voice coil wire which is soldered to the other side of the “hard to access” terminals, is VERY easy to damage with too much heat, physical stress, etc. Trust us here….if you do not have great experience soldering terminals, do not attempt the original terminals at all! Part of the issue here is the magnet’s desire to pull your soldering iron’s tip into its strong field whilst you are trying to work! You will simply want to release the tweeter by removing its 4 outer-most screws. Then, cut the 2 wire as far from the tweeter as you can while feeling comfortable re-soldering the existing wire when they have been returned to you. Various KEF models will vary tremendously how much slack you might find speaker to speaker. Be careful here! You may also want to attach some large tape of a pull-string, etc. to ensure the leads do not disappear down into your cabinet too far if released. This can be very difficult if you forget. Again, some models have almost no slack while others offer a mile. Be careful!
2 -If you are sending the pair (which you should do no matter), the two tweets can be placed face to face and the domes will not touch. However, I like to place a couple of small pc’s of thin cardboard between them around the edges with a few strips about 3” by .5” (7.5cm by 12mm) just to prevent the faceplates from rubbing together in shipment. Then tightly bind the pair of tweeters by “wrapping” them with packing tape all the way around by a few layers. If shipping only one tweeter, feel free to attach a small plastic cup from say a restaurant that serves ketchup etc. to the front of the tweet and secure with packing tape. Or, of course, you can cut a hard pc. Of cardboard the same size as the tweeter’s face and then wrap with packing tape as well around the magnet. Wrap the package further with some bubble-pak and then ship to us with as much additional safety as you see fit. We recommend a few inches all the way around in bubble-pak and then at least 4 more inches of packing peanuts all the way around.
3 -Reinstallation- You will simply be stripping back about 1” of the original KEF pvc insulation about 1” on both ends. Most KEF’s used blue and brown for their colors. Just be sure to match these carefully. Be sure to slip on a pc. Of 1.5” heat shrink tubing before twisting the two leads together if you are insulating by heat shrink. One can use electrician’s tape but I do not recommend. Please use your solder of choice with a nice pencil iron preferably 20-45 watts with a nice quality silver solder or decent quality 60/40 solder as that is what Kef used. We recommend cardas solder or some decent silver content solder for the higher end models. Solder kits with the 4 heat shrink pcs. And cardas solder are available for a nominal fee. Once neatly twisted and soldered back together, slide the heat shrink boot over your new solder joint and carefully heat the shrink with a heat gun, lighter, etc. until it has adequately shrunk the insulation down to the wire. Once complete, simply line the tweeter up by ensuring the kef logo is in its correct location and reinstall the tweeter flush to the baffle. Gradually tighten the 4 outer screws and be ready to be blown away at the sound of your old kef tweeters now that they sound original again.
Thanks for choosing this service. If your tweeters are in good condition and can be rebuilt without issue, you will be amazed at the improvement. My best, Tim
I've always loved the sound of my KEF 104/2 speakers: full bodied, yet clear and without coloration. Too bad the KEF T33 tweeters (type SP1191,
4 Ohm version) won't last. The ferrofluid inside the T33 dries out over the years, resulting in a reduced high frequency output. Unfortunately, one of mine also went belly up (the dried out ferrofluid also reduces the cooling capacity, making the tweeters extra vulnerable). I tried to replace them, but alas, the T33 is simply not available anymore.
A lot of people on the web suggest Morel MDT29, 4 Ohm tweeters as a replacement. I ordered a pair of these on ebay, where they were advertised as being a "drop in replacement". As it turned out, they were
not: I had to get a Dremel and modify the cabinets to make them fit. At first, I was satisfied with the sound, but in my memory, the original
T33 sounded better, spicier and fresher. It turned out that on female voices, the Morels showed a strange coloration on sibilants.
So, when I got my hands on a pair of second hand KEF T33 tweeters, I sent them to Luminous audio for restoration. Luminous audio did a marvelous job, and within a few weeks, the tweeters were back in place, fully restored. As I write, the sparkle is back again, harpsichord sounds alive and airy, and gone is the coloration on female sibilants.
To whom it may concern: get your T33's restored by Luminous audio, and stay away from the Morels!
Thank you for going to the trouble of making this service available. What a difference! Amazing how they deteriorate over time, until one day you suddenly realize that they really sound pretty darn bad. I remember now how they used to sound and how the tweeters actually color the mid range as well; pretty sure I'm hearing some stuff that used to be there but had disappeared until now.
Hi Tim, It’s Steve,
Guess what?.... I'm keeping my amp. That’s how much difference I notice with the rebuilt T-33’s.
My point about all this is I'm not wealthy, but I been around HIEND since 1974 with my Marantz 4270. My Kef 104.2s are now amazing again. My "ears don’t lie.” It’s true. Those t-33 rebuilds restored them to the glorious speaker they are. Anyway, my opinion is these will now hold their own against anything out there.
Steve from Florida
My KEFs are re-assembled now and they sound like a dream again. It was worth all the trouble, not only with the tweeters, but also with repairing the woofer donuts and upgrading the cross over filters. A major operation and a mega result.
So MANY THANKS for your involvement here Tim. I wish you all the best, including success with your Luminous business!
Hi Tim, It's been about a month since I reinstalled my KEF 107 tweeters. I wanted to live with them for a while before writing my findings. The first thing I noticed was that the top end seemed a bit more extended, but what I really noticed and appreciated most was when an instrument stopped playing you can hear much more of the decaying of the sound. As an example, when you hear the sound of a cymbal, it should fade off gradually. Before I had my tweeters repaired the sound would start to fade and then it would just stop because of the hardened ferro fluid. Now the sound just fades away naturally as it was meant to. The sound is so much more alive and much better balanced than it was before servicing. Thanks again for providing this invaluable service.
“Well worth the upgrade! Before having the ferro fluid changed, my KEF 103/3's were boring to listen to. "Lifeless" and with vocals that had high frequencies and mids separated in space. Also suffered with "side-squirts". Now, however, the vocals are point sources, livelier, without the s-s and more like how I remember them. Better sound stage. Great news all round and well with the upgrade price. Tim is very helpful and the repair service was faster than I expected. Removal and installation was simple and Tim's notes are very useful in helping you remove and reinstall the tweeters. Thanks again Tim! Best Regards, Jan”