KEF 104/2

[Juha]

I have wanted to try some large format speakers from B&W or KEF for some time.

Had a chance to buy KEF 104/2 pair recently. These are single wire pre 1990 models.
Tweeters had been upgraded to Morel MDT29.

http://hoone.com/kef.jpg

The sound is effortless. Jazz and acoustic music bring out the musicality of KEF 104/2.
They are neutral. The sound is not flashy or somehow hyped.

KEF 104/2 is not very popular on AOS. Could it be that its complicated mechanical construction
with five speaker elements, metal rod between two woofers and 16 caps on the crossover put off
restorers. Or maybe it was expensive 25 years ago that there not many available.

[agk]

I can't speak for others but no negative vibes from me. Great speakers doing great things in what looks to be a great setup.

[istari_knight]

I had a pair of Reference 2's for a bit. Really impressive speakers but a PITA to restore as you say.

IIRC the tweeters in 104/2's commonly suffer from dried up ferrofluid which can cause them to "stick" but it can be removed or even replaced if you're careful.

[The Barbarian]

I know someone who has some all four of the units have rotted away

[YNWaN]

One of the best speakers Kef have ever made IMO. They were expensive when new and were an ambitious and complex build - would be very expensive today.

[The Barbarian]

The kid i know paid £500 the pair. The Brass Plaques on the rear aint a cheap thing to produce..

[Juha]

To buy these speakers I had to first take the ferry from Tallinn to Helsinki. Then drive 500 km. Then back to Tallinn on the ferry.
But it was all worth it. This was was a bargain at £300.

I was going to recap the crossovers. Then found out that that would involve a total of 32 capacitors.
And according to internet stories KEF had matched all components carefully.

Here is a cross section of KEF 104/2 (This is the later after 1990 model)

http://hoone.com/kef1.jpg

[YNWaN]

32 caps is a lot and, depending on the replacements, could be gigantically expensive. I still think it is worth investigating though - having a look at what has actually been used.

[The Barbarian]

Can't be as expensive as totally rebuilding a pair of Ferrograph 'S1' they uses around 8 Inductors, 10 caps but four are 100uF the price of those in Polyprops is vary expensive let alone large in diameter.

[agk]

Can't be many tube loaded hifi speaks about. Usually a car thing iirc.

[Beobloke]

I can't speak for others but no negative vibes from me. Great speakers doing great things in what looks to be a great setup.

None from me either. Great pair of speakers and those look very smart.

[Sovereign]

Lovely looking set up.
I run a building company, we carried out a fair bit of work at the KEF factory in Maidstone, very interesting experience seeing the factory, production and SHED loads of KEF speakers old and new.

[audio39]

To this day I think of the 104/2 as one of the best speakers ever mass produced.

Last year a gent here in Canada refurbished a biwire pair...and I mean refurbished to the nth degree. They looked amazing and I struggled not to make them mine, they wound up selling for $1900 CDN with custom made metal plinth/feet for each speaker.

The 104/2 are very worthy of a full refurb.

Enjoy.

[hoopsontoast]

Yep I agree, great speakers. I would have kept mine had the bass not been a bit too fruity for my room.

Very underated I think, slip under a lot of peoples radar.

[petrat]

Lovely speakers, those are!
Tallinn is a lovely city, too ... or it was when I visited 12 years ago.

[Juha]

Thank you all for your friendly comments.

I am still enjoying my KEF 104/2 speakers.
I found out how to make them sound even better.

I was using the wrong speaker cables!
Started testing cables and found out that speaker cables did make a difference at least on these speakers.
They were sounding just a little bit too dark and dull.
The bad cables were called the Qed Balanced Design speaker cable.

The cables that opened up the sound with Nakamichi Amplifier 1 are
Mogami Neglex 2513 also called "Blue Rocket"
(cable disclosure: bought from a car boot sale 5 years ago at £5)

[Juha]

Recapping Kef 104/2

After some hesitation I decided a crossover recap had to be done.
The crossover is buried deep in the complicated speaker.

2 hours of reading web instructions and pictures. 1 hour of work to open one speaker.

The Kef build quality is fantastic. The woodwork is first rate. All fixings are top quality.
Doing this brings back the old quality at low price idea. How much would these cost today??

Here is the crossover. Never seen anything like it. Size about sheet of A4 paper, weight 2.5 kilos.

http://hoone.com/kefxover.jpg

I measured the caps in situ. Seems like higher values are badly off. Like 300 mfd is now 158 mfd.
Many low valued measured ok. Going to replace all of them anyway.

It has 16 Alcap caps. For reference, here is the list of caps for one 104/2 mark 1 (1984)

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

[KONDO]

The kid i know paid £500 the pair. The Brass Plaques on the rear aint a cheap thing to produce.. hi that was on the Raymond cooke limited edition ones, had them in black, and the older teak ones, should never have sold le ones, great speakers

[Juha]

KEF 104/2 Recap is Now Done

Falconacoustics (http://falconacoustics.co.uk) was able to supply high quality 2% and 3% tolerance matched
handpicked 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.

Each speaker took a whole day.
To get to the crossover the whole speaker has to be dismantled.
This is 40 bolts to be opened.
The crossover de-soldering, cleaning and soldering new parts was 2 hours / speaker.
I did this slowly to obtain good shiny solder joints.

After the crossover was ready all scuff marks and small dents on the wood finish were taken care of.
Liberon Finishing Oil polish was also done.

When refastening all 40 bolts I used small quantities of general purpose oil. This helped tremendously.
The bolts went on much smoother.

Was the sound any good?

Yes, yes, yes.
The KEF's were always a bit dark sounding before.
This is now totally cured.

Would I now recommend a recap? Yes, but the complicated construction of 104/2
and some bits that need careful handling must be considered.

[struth]

Theres a set of those xovers on ebay at moment