Kef 104 Crossover help.

[Mattias l]

Hi again Mattias,

I am not surprised that you are confused, and you are correct in saying that you are not good at this.
I think you have been lead by too many opinions about differences in sound between brands of capacitors being able to improve the sound of loudspeaker systems for which another matter has to be addressed to actually cause a real improvement.
Kef addressed the other matter when trying to improve the original 104, and their result is the 104ab.

If you like the sound of the original 104, then copy EXACTLY the capacitances that are in the Specification
for it, OR, as close as you can buy to those.
Closest available now is 4.3uF and 5.0uF, or 5.1uF in some brands.
Those will work.

Buy in +/- 5% Tolerance- that will get you close enough.

I recommend that you do not use 4.7uF unless you intall the 56 ohm resistor I described.
If you use the 56 ohm Parallel connected resistor, then use 4.7uF and 5.6uF in the treble filter, and 5uF in the bass filter.
This will give you an improvement in midrange coherence over the old 104 design and towards the 104ab design.
This will cause a more significant audible result than any expensive capacitor priced higher than ClarityCap PX series.

I recommend that you do NOT use 4.7uF + 0.33uF in Parallel to create the 5uF cap.
This is a complicated topic, and may confuse you more.

Save the remainder of your money to use for better inductors later,
for after you have listened with the new capacitors installed,
and decided about the switched/tapped bass-mid inductor position.

That is the best "middle ground" I can think of.

Thanks mate for helping me out.

I ordered 2 of the 4.3uF Claritycap ESA Range polypropylene Tolerance:..+/- 3% and 4 of the 5.0uF Claritycap mfd PX Range polypopylene Tolerance:..+/- 5%


/Mattias

 

[alan-1-b]

audible differences

Hi Mattias,

good, you have chosen something which will give results close to the original 104,
though new technology capacitors will never sound like the old capacitors.

I am surprised that you want only to try to keep the original 104 sound,
and not do a modification to allow more accurate reproduction of the audio signal,
but that is for you to decide.

After you have installed the capacitors, and listened for a few days,
please do post here what you have heard with the new capacitors in comparison to the sound with the old capacitors.
That will be interesting to know - the differences you and your girlfriend hear.

 

[Mattias l]

Hi Mattias,

good, you have chosen something which will give results close to the original 104,
though new technology capacitors will never sound like the old capacitors.

I am surprised that you want only to try to keep the original 104 sound,
and not do a modification to allow more accurate reproduction of the audio signal,
but that is for you to decide.

After you have installed the capacitors, and listened for a few days,
please do post here what you have heard with the new capacitors in comparison to the sound with the old capacitors.
That will be interesting to know - the differences you and your girlfriend hear.

Maybe I will do a modification later I just wanted to get the speaker in better shape before were moving to OZ, they are the only speaker we have now since I've sold my Focal Twin 6 Be, I've stained them red and I will paint the front silk black, the original colour was in really bad condition.

/Mattias

 

[alan-1-b]

sold that Focal !

Hi Mattias,

you sold Focal Twin 6 Be !

Is that the Active/bi-amp model ?
If so, I suppose you are thinking the mains supply electricity in Australia may be a different Voltage than your Focals have transformers fitted for.
That Focal model is sold in Australia, but perhaps with a different mains transformer fitted.

Do you think the Kef 104 is almost as good as the Focal Twin 6 Be ?


I have a cousin in Australia, currently in Sydney, NSW.
What city in Australia are you moving to ?

 

[Mattias l]

Hi Mattias,

you sold Focal Twin 6 Be !

Is that the Active/bi-amp model ?
If so, I suppose you are thinking the mains supply electricity in Australia may be a different Voltage than your Focals have transformers fitted for.
That Focal model is sold in Australia, but perhaps with a different mains transformer fitted.

Do you think the Kef 104 is almost as good as the Focal Twin 6 Be ?


I have a cousin in Australia, currently in Sydney, NSW.
What city in Australia are you moving to ?

Yes I've sold them and it was the active/bi-amp model.

I don't think I can compare Kef 104 with the focals, with a tube pre-amp they sounded so nice, clean and big, with a non tube amplifier they can sound a little bit cold.

We are moving to Queensland and the Gold Coast.

/Mattias

 

[Mattias l]

All the capasitors have arrived now, the 4.3uF Claritycap ESA were huge

I have decided not to change the crossover so I will try to fit the capasitors on Kef's original crossover, I have bought this cable for internal wire: PTFE silver plated copper wire 19/0.2 Hifi Collective

I've used red wooden stain on the speakers and I've put 4 layers of high gloss boat varnish on them with good result, the front is silk matt black.

I hope I get some time of work this weekend so I can start putting all things together.

/Mattias

 

[frperdurabo]

I'm not sure if I should post this here, or start a new thread.

I'm thinking of rebuilding the crossover in my Kef Corellis. I like them, overall, but the t27 has an edge to it on certain music. Would replacing the high-pass section of the Corelli crossover with the one from the 104ab be a good idea? I realize the Corelli has a different version of the B200.

 

[alan-1-b]

where to look for KEF information

I think the 104ab crossover's tweeter filter will not likely solve the problem you are hearing.
New polypropylene capacitors may alleviate if the fault is the old caps are leaking or now dried to lower than their specified capacitance.

For information about the different Kef models and their crossovers I recommend that you go to:

Home Page hifiloudspeakers.info

In that web-site is a Forum also, and I recommend you ask your question there.

***************

Hi Mattias,

well, you will have to squeeze that huge cap in !

Post what the sound is like after you have listened for a while to the changes.

 

[Richiebuoy]

Well, now you have to decide whether spending a lot of money to get some exact value, overpriced capacitor to replace the caps in a 30 year old speaker (probably still good caps, by the way)



David S.

I thought the general belief was that caps only have a life span of 10 - 15 years before they start going down hill ?

I ahve just bought a pair of replacement 104ab cap. kits from Falcon Acoustics but now wonder if I should bother fitting them, my speakers sound fine to me but I dont really know how they should actually sound....

I have a pair of 104's and 104ab's and the ab's are much better, more open and more detail with less colouration.

 

[alan-1-b]

types of capacitors

What type of capacitors are in the Falcon kit ?

It is Electrolytic caps that have finite lifetime.
Well made plastic film caps will last almost forever - longer than we will live !

Falcon sell both electros and metalized polypropylene caps, thus you could have either.
What is printed on each of them ?


Thankyou for commenting on audible differences between 104 and 104ab.

 

[Richiebuoy]

Its these here KEF 104aB REPLACEMENT CAPACITOR SET

I went for the low loss 2% option. Let me know what you think.

On the same subject, folk on the Kef forum (maybe biased) believe that a well sorted pair of 104ab's will blow away any modern speaker sub £1000. Given that in 1970 they cost roughly half the price of a family car then maybe there is some truth in this. I my case they were much better than my modern M.A's.

 

[Mattias l]

I think the 104ab crossover's tweeter filter will not likely solve the problem you are hearing.
New polypropylene capacitors may alleviate if the fault is the old caps are leaking or now dried to lower than their specified capacitance.

For information about the different Kef models and their crossovers I recommend that you go to:

Home Page hifiloudspeakers.info

In that web-site is a Forum also, and I recommend you ask your question there.

***************

Hi Mattias,

well, you will have to squeeze that huge cap in !

Post what the sound is like after you have listened for a while to the changes.

I've just assembled one speaker now and did a quick listening test and I just say WOW so much clearer, warmer and more exact, will do the other now

/Mattias

 

[alan-1-b]

The capacitors, & to Mattias

Its these here KEF 104aB REPLACEMENT CAPACITOR SET

I went for the low loss 2% option. Let me know what you think.

On the same subject, folk on the Kef forum (maybe biased) believe that a well sorted pair of 104ab's will blow away any modern speaker sub £1000. Given that in 1970 they cost roughly half the price of a family car then maybe there is some truth in this. I my case they were much better than my modern M.A's.

Richiebuoy,

in that set the blue ALCAPs are Electrolytic capacitors.
Only the black Solen/SCR is a metalized polypropylene cap.

I recommend you cancel that order, or if you have received it do not use them but send back and request Falcon send you the Solen/SCR alternates of the 4 ALCAPS.
They do stock them.
The Solen/SCR will cost more, but have very long life {longer than our life}, and do not have the audible smear problem caused by the Dielectric Absorption of all electrolytic capacitors.

Did anyone in the KEF Forum post anything about the types of capacitors ?


***************

Hi Mattias,

good to hear that you like the result.
Next tell us after you have both speakers finished and have listened for a few days,
because some impressions about the sound will not become apparent till after you have listened for more than 1 session.

 

[Mattias l]

Richiebuoy,

in that set the blue ALCAPs are Electrolytic capacitors.
Only the black Solen/SCR is a metalized polypropylene cap.

I recommend you cancel that order, or if you have received it do not use them but send back and request Falcon send you the Solen/SCR alternates of the 4 ALCAPS.
They do stock them.
The Solen/SCR will cost more, but have very long life {longer than our life}, and do not have the audible smear problem caused by the Dielectric Absorption of all electrolytic capacitors.

Did anyone in the KEF Forum post anything about the types of capacitors ?


***************

Hi Mattias,

good to hear that you like the result.
Next tell us after you have both speakers finished and have listened for a few days,
because some impressions about the sound will not become apparent till after you have listened for more than 1 session.

I have listened to them a couple of hours today before I had to go to work and they sound more open and warmer as time passes on, I was suprised after some time of listening that I actually forgot to listen after improvements, I just listened to the music and changed songs and records, it was fun to listen to the speakers They sound a little bit simular to

I still have the speaker binding post to assamble (thay are on the way) and then I'm done with them.

They sound a littlet bit similar to the Focal's I had but warmer, they lack a little bit in bass but are more pleasant to listen to

It was a real good upgrade and it didn't change the speakers chracter but made them sound batter with the same warm sound, It will be interesting to try them with a better amp and cd-player, I can live long with this speakers.

/Mattias

 

[Richiebuoy]

Thanks Alan, I'll get in touch with Falcon.

 

[psoul]

Thanks Alan, I'll get in touch with Falcon.

curious to know if u switch to falcon better capacitors replacement and how they are?
best
ale

 

[thisisstuc50]

Thanks mate for helping me out.

I ordered 2 of the 4.3uF Claritycap ESA Range polypropylene Tolerance:..+/- 3% and 4 of the 5.0uF Claritycap mfd PX Range polypopylene Tolerance:..+/- 5%


/Mattias

Hello Mattias

I have just purchased a kef 104 and am looking to do a recap of the crossovers

Thank you for posting the 6 caps that you ordered.

I wonder if you could tell me where you placed them in the circuit.

I've attached an image of my crossover for reference

If you could just say the 4.3uf in the middle... or the left... or the right... and then the other 2 in the other positions that would be great

Perhaps even draw on the photo I send

Thank you in advance

Kind regards

Stuart

 

[thisisstuc50]

D'oh

I see now that its written on the side!

Our of interest, what v did you go for on each capacitor?

I can only find either 250v and 630v

Thanks