KEF 107 Recent restoration

ttan98

Member
2006-04-04 11:24 am
Melb
Yes it would be interesting to see how replacement with high quality modern components would change the sound .....maybe someone has else has done so.

When i undertook this restoration project one of my goals was to keep the Kefs as original as possible. The restored Kefs sound amazing and should not require further restoration or repair for a long time. If at some point in the future, additional repairs are required and I cannot source original components then i will utilize modern components. So until then I will enjoy them in their near original state.
you will have many years of enjoyment of these speakers. I found our ears combined with the pursuit of an upgrade, you will find you will be "tired" of the sound. The ears are very smart they will very quickly learn the sound reproduction of these speakers, if you are not the upgrade type of guy will be happy with them for many years to come otherwise upgrade may be in the pipeline.
Enjoy a very an excellent pair of speakers at a "bargain" price.
 
I see ATBI capacitor in LF crossover...which looks very similar to ACLAP bipolars...ohw did you decide to use that one ? Its bit confusing as F&T makes ATBI capacitors and on that particular one I see ALCAP ATBI which is confusing to me. I have recapped my Xover with F&T ATBI in less important and ClarityCap PX polys in more important positions.
You still enjoying these beauties?
 

diyiggy

Member
2019-01-16 12:22 am
they all make two sort of bipolar lythics : rough and smooth foil. Smooth foil are bigger at iso capacitance but have better ESR and more linear in the audio frequency range till the highs. At Alcap, those are called LL for Low Loss, which is at FT caps: ATBIG. ATBI being for rough foil if my memory serves me well.

So you could swap LL for polypro. In the meantime polypro has way better ESR, i.e. resitance and it can affect the spl level, in some speaker you will not notice it in some others you may for the best or the worse...

Which is important in the Ref Kef serie is to respect first the capacitance values : 5%, 2%, 10% : the tolerance is marked on the filter datasheet. For the ESR it should be also important in the case you see also no resistor value as the cap ESR is maybe a part of the wanted attenuation for the desired loudspeaker power response.
Best is to try in real life if polypro change is an improvement or not, ears are sensible enough.

FT caps often measure very precisily, more than Mundorfs they also make. It is an ok swap from the Alcap that get difficult to source. Falcon Acoustic has not sourced the old kef Alcap particular values not seen elsewhere for a while.
 

rbg1

Member
2021-12-08 12:04 am
I see ATBI capacitor in LF crossover...which looks very similar to ACLAP bipolars...ohw did you decide to use that one ? Its bit confusing as F&T makes ATBI capacitors and on that particular one I see ALCAP ATBI which is confusing to me. I have recapped my Xover with F&T ATBI in less important and ClarityCap PX polys in more important positions.
You still enjoying these beauties?
Yes, absolutly enjoying the Kefs... I listen to them at least weekly and every month or so have my buddies come over to my place to spin some vinyl and have a few beers.
With respect to replacing the caps in the mid and low xovers i went with the ALCAPS given they were the oriiginal supplier for the speakers and that i could source the capacitor sets from falconacoustics.co.uk. I purchased them in Nov/Dec 2021.
 
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