Kef 104/2 restoration

[gkt]

Hi to everyone,

I am presently trying to restore my Kef 104/2 speakers... Foam donuts completely shot. Tweeters T33s waiting for a ferrofluid replacement. I am just struggling to know some more about the capacitors.. I would like to replace them all, is it normal for two identical valued capacitors to be different physical sizes??

Thanks for any light that could be shone my way...?

Gary.

[struth]

Caps have different voltages and are of differing types. Best to replace like for like. Electrolytic s have +&- .. film types for instance dont and can be fitted either way .
There are a couple of threads recently if you look about of guys redoing these very speakers

[gkt]

Caps have different voltages and are of differing types. Best to replace like for like. Electrolytic s have +&- .. film types for instance dont and can be fitted either way .
There are a couple of threads recently if you look about of guys redoing these very speakers

Hi Grant thanks so much for your reply:)

I have 4 x 100uf 50v capacitors but 2 of them are coloured a lighter blue and are also larger in physical size.. this is throwing me!? I am about to order replacement sets but i think I would just like to understand before I order.

Thanks again.

Gary.

[struth]

Sizes can vary a bit and colour is no indicator. Get the best you can afford and you wont go far wrong. Hifi collective do great stuff... there's also rs and Farnell. .. cheaper stuff can be found on ebay. Depends what you want to do really.. The dear ones may be pricy but good. Vishay etc

[gkt]

Sizes can vary a bit and colour is no indicator. Get the best you can afford and you wont go far wrong. Hifi collective do great stuff... there's also rs and Farnell. .. cheaper stuff can be found on ebay. Depends what you want to do really.. The dear ones may be pricy but good. Vishay etc

Ok great thanks for your help! ;)

[Audio Advent]

One awkward thing to note about the Kef Reference range from the 80s and 90s is that the components were measured for their actual values and matched between the cross-overs. e.g. if the components have a tolerence of +/-10% both would be matched to say +/-0.5% tolerence or so..

I say awkward because this then throws up the dilemma of whether you will be better off with new and potentially better quality components or if you will end up with a less accurate and less well matched pair of crossovers with whatever sonic consequences that may have.

Possible that the different capacitors measure a certain value and hence the different ones chosen (or they could have been replaced before).

I've read of people replacing the T33 with either a morel tweeter (something with a 33 in the model number) or a scanspeak 93000/95000/97000. Both appear to be T33 replacements judging by their basic design qualities like resonance and crossover point and impedance curves, but they do differ in sensitivity. The scanspeak ones definately have the same bolt points but have a very short horn which doesn't fit inside the kef baffle so it needs to be widened. So, they can be options too as a potential upgrade.

[walpurgis]

Hello Gary. Welcome to AOS.

Tell us more. What music do you listen to and what is the rest of your system?

There are sections here covering all aspects of Hi-Fi. Try starting a thread in the Blank Canvas area where everybody will see it and ask your speaker questions, I'm sure you'll get plenty of response.

Projects are popular and you can post in the Drawing Board section with photos etc., if you want to show us what you're doing.


Enjoy the forum,
Geoff.

[gkt]

Hi Geoff,

Thank you... I shall try and find the Blank canvas page..??! will list system in a short while...;)

[gkt]

Thanks for all your help.. I do appreciate it!!;)

[Juha]

I restored Kef 104/2 crossovers some time ago.
Did a complete recap.

Falconacoustics (http://www.falconacoustics.co.uk/) was able to supply high quality 2% and 3% tolerance matched
hand picked caps. The nominal tolerance of these Alcap caps is 10%. By measuring each cap
I got caps that are a very close match to how KEF used to do it.
A set of 34 caps for two speakers cost about £100.

Falconacoustics is the only supplier that has all required Alcaps available.
Some lower MFD values are available from other sources, but not the high MFD ones.

There is no way to start rolling different cap brands here. I mean each crossover has 16 caps!

Here is a list of 104/2 mark 1 caps:

MFD Voltage Type Description
3.3 50 LL Blue Alcap
4.2 50 LL Blue Alcap
4.2 50 LL Blue Alcap
7 50 LL Blue Alcap
10 100 Blue Alcap
16 100 Blue Alcap
25 100 Blue Alcap
30 50 Black ELCAP
50 150 Black ELCAP
100 50 Blue Alcap
100 50 Blue Alcap
100 50 Blue Alcap
100 50 Blue Alcap
240 50 Blue Alcap
450 50 Blue Alcap
600 50 Blue Alcap

http://hoone.com/kefxover.jpg

[Juha]

This is the tweeter for Kef 104/2.
104/2 has very difficult physical tweeter fastening.
This replaces the Kef T33A.

Morel MDT29-4 (4 ohm) Textile dome tweeter (https://www.madisoundspeakerstore.com/morel-soft-dome-tweeters/morel-mdt29-4-4-ohm-textile-dome-tweeter/)

[gkt]

Nice!! Thank you ;)

[gkt]

All this information wow!! Cheers.....:)

[Eagle owl]

Hello and welcome Gary.

Geoff. :wave:

[gkt]

Hello and welcome Gary.

Geoff. :wave:

Thanks for a warm welcome ;);) It's all new to me!:scratch: