KEF 104.2 tweeter

[jan.didden]

Hi,

As part of a sale I got a pair of KEF Reference 104.2 speakers. Basically sound except that the tweeters seem to have lost their output.
I found several sources saying that after many years the ferrofluid in those tweeters dries out and the voice coil starts to stick.

So it seems I have a choice of replacing the tweeter (there are non-KEF replacements) or renewing the ferrofluid.

Anybody here who has done this for this particular tweeter?

Jan

 

[mlloyd1]

Hi Jan,

I've had a pair since buying them new in mid 1980s.
Replaced the tweeters in both from a recommendation in post 7 of this thread: kef 104/2.

mlloyd1

 

[mlloyd1]

I just checked, looks like they still carry them:
MW Audio MT-1191: 1 inch Dome Tweeter for KEF 104/2 Speaker | Midwest Speaker Repair
I had to wait for mine when I ordered them - they had run out and had to wait on a new batch to be manufactured.

mlloyd1

 

[sorenb]

I have replaced the ferrofluid, I got from some eBay seller.
Disassemble the tweeter are pretty easy.
I cleanout the gap using filter-paper ...takes about 10-15 pieces to remove the old oil
and used some q-tips wetted with some isopropanol to clean the coils

finally used a syring to apply 0.1ml ferrofluid, before re-assemble the tweeters

You might find more info here: Home Page hifiloudspeakers.info

 

[Paddy Garcia]

I second the recommendation to clean out and refill the ferrofluid. It's not hard - I've done 3 pairs now after studying the various videos. IMO the original tweeter is probably 50% of the magic of the 104/2.

I think I've got a spare couple of vials of fluid, PM if you want them.

 

[Henkjan]

Hi,

As part of a sale I got a pair of KEF Reference 104.2 speakers. Basically sound except that the tweeters seem to have lost their output.
I found several sources saying that after many years the ferrofluid in those tweeters dries out and the voice coil starts to stick.

So it seems I have a choice of replacing the tweeter (there are non-KEF replacements) or renewing the ferrofluid.

Anybody here who has done this for this particular tweeter?

Jan

Hi Jan,
Just wondering if and how you progressed with the 104/2's?

asking for a friend 😀
Restauratie KEF Reference 104/2 - forum.zelfbouwaudio.nl

 

[jan.didden]

Henk-Jan, die zijn al weer een tijdje weg. Ik weet niet wat die persoon er verder mee heeft gedaan.

Jan

 

[Henkjan]

OK, bedankt anyway.

 

[system7]

Translated... they have been gone for a while. I don't know what else that person did with it. 😀

Not hard to swap out dried up ferrofluid:

Replace ferrofluid in tweeter - a B&W tweeter as an example

You can even remove it altogether as a quick test. Careful when you lift off the voicecoil. Just go easy on the volume.

 

[diyiggy]

The FF on this speaker is a very light one on the indice and just there for a little help on the cooling side. If you have not the ref take any one but putting vet few : less than the half height.


Or you have this, very close enough if not best, according what you like with music . I find the T33 of the Kef 104/2 I already refurbished once to be forgiving so musical.


I have found this speaker to make music with the acurate strong amp and room size w/o the cube.


if you want a new tweeter, I find this one close enough : Boutique Haut-parleurs & Audio DIY

 

[Henkjan]

George already did replace the ferro fluid, but still the tweeters did not measure right. he's now trying the Audax TW025A2, word has it it is a drop-in

 

[diyiggy]

... less good imho. Thete is also the Morel 294 at Meniscus iirc but less good too.

One has to measure the impedance of the new tweeter around 3k to adapt the tweeter filter...the 7.5 uf and after...
The Peereless seems a good compromise since the 25tg is non sold anymore.

 

[Henkjan]

attached measured response of both tweets with ff removed (green, black) and with ff (red). does not look like what it should be

 

[Henkjan]

.... the Audax TW025A2, word has it it is a drop-in

... less good imho.

less good in what aspect?

 

[diyiggy]

measure above 10 K hz is totally another driver than the T33B in the Audax, Morel seems closer but some have experienced better hearting quality in the kef 104 ref with the Peereless DX I linked and its cheaper brother alternative still in the catalog.


now the FF was very light ferro damped so newer may act too much. Also maybe the recoating In the one I refurbished the two original dome had aged differently : one was harder at the finger than the other mellow one ?!

 

[Geosto]

Hi nice to see this thread.😀
Bedankt Henkjan voor de voorzet.😎
I now have ordered the Audax TW025A2.
The reason for this is that i hope that this unit will be a bit more hold back.
At this moment i have the T33 without the ferro fluit in place and the sound quite aggressive, tuning up the volume is not pleasant this way.
Below you see how the speakers look like at this moment.

When the Audax tweeters are installed i will give you an update of the sound.

 

[markbakk]

Dutch forum merger or takeover in the make? 😀

 

[diyiggy]

oh no a car seller bought that former good looking loudspeakers, they are awfull with this industrial gray : re sent them to the painting cabin with true white or black gloss 😉

 

[Geosto]

Yes it was a good looking speaker😕

The gray is a matter of taste of course.
I need to polish the gray so it will be gloss.

 

[diyiggy]

Indeed, the new gloss is much nicer than this picture. Have you the front grill, I read they are mandatory for a better soundstage. these spekers literally disseaper ! Not bad for a design of the early 80s 🙂