SpeakerTalk

Caliente

Ok, I was hoping to join this site to gather more info regarding my unique Kefs. But due to having a small listening room I have decided to let these go.

Pictures can be found at http://s301.photobucket.com/albums/nn63/Calientezx/Kef

They were produced in 1973 for the BBC but never went into commercial production - only 6 or so were made and these are possibly the only ones still in existence. They were restored by a well known and respected hi-fi fanatic - I obtained them last March, and despite trying various combinations of amp/cables I cannot avoid a degree of boom. I must admit that they give excellent results with modern jazz and world music, but don't cope too well with Led Zeppelin & Van Halen type of thing.

If interested please contact me premsyl@tiscali.co.uk I'm based in Leeds

ColinR · Posted: Mon Jul 06, 2009 9:25 pm Post subject:

I believe there were more than 6 pairs like yours which ended up in the hands of both KEF and BBC employees.

Numbers 5 & 6 are rebuilds, as my least favourite Norwich speaker stripper got there first, luckily ex-KEF man Malcolm Jones of Falcon had the plans, so Peter (another Speakertalk member), who bought just the boxes did an expensive rebuild.

Any chance of a listen Very Happy

?
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This post or any other information supplied to this website or any other by myself is not available for any form of commercial purpose i.e. to hi-fi magazines or as sales and marketing material for sleezeBay or Audiodogging pimps and the like.

Caliente · Posted: Mon Jul 06, 2009 10:34 pm Post subject:

Colin - ah, you seem to know about these

These are sn 3 and 4

Are you aat all interested in looking after them as part of our speaker heritage?

Rob

ColinR · Posted: Mon Jul 06, 2009 10:55 pm Post subject:

I know bits and pieces, but I really would like to examine them more closely as they're so "off the wall" but meant to be hung on one!
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This post or any other information supplied to this website or any other by myself is not available for any form of commercial purpose i.e. to hi-fi magazines or as sales and marketing material for sleezeBay or Audiodogging pimps and the like.

proffski · Posted: Tue Jul 07, 2009 6:56 pm Post subject:

Utterly fascinating, were all the units directly driven or is there an ABR lurking in there somewhere?

Andy.
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I contend that for a nation to try to tax itself into prosperity is like a
man standing in a bucket and trying to lift himself up by the handle.
-Winston Churchill

Caliente · Posted: Tue Jul 07, 2009 6:59 pm Post subject:

proffski · Posted: Tue Jul 07, 2009 7:09 pm Post subject:

Oh come on, take a peek inside, pretty please... Smile

_________________
I contend that for a nation to try to tax itself into prosperity is like a
man standing in a bucket and trying to lift himself up by the handle.
-Winston Churchill

Caliente · Posted: Tue Jul 07, 2009 7:39 pm Post subject:

proffski · Posted: Tue Jul 07, 2009 7:53 pm Post subject:

I cant even afford a wallet!
_________________
I contend that for a nation to try to tax itself into prosperity is like a
man standing in a bucket and trying to lift himself up by the handle.
-Winston Churchill

SaSi · Senior Contributor 200+ Joined: 24 Aug 2008 Posts: 256

My guess is there is one B139 active and two PRs.

ColinR · Posted: Wed Jul 08, 2009 10:07 am Post subject:

Peter's rebuild of 5 & 6 used two SP1044s and a high power SP1333, unfortunately I've no information about the crossover points or series/parallel configurations.
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This post or any other information supplied to this website or any other by myself is not available for any form of commercial purpose i.e. to hi-fi magazines or as sales and marketing material for sleezeBay or Audiodogging pimps and the like.

speakerguru · Posted: Fri Jul 10, 2009 8:27 am Post subject:

1973 is before I joined KEF, so I can't help. I don't recall anyone talking about these, either, probably because they were busy selling LS5/1ACs to the newly formed commercial radio stations and installing the new 'computer' by '75 when I joined.

Looking at your photos, my guess is that they are basically Concertos in a custom box but with 2 PRs replacing the usual vent. PRs are better than vents for avoiding turbulent air flow.

The PRs may well be modified as regards moving mass to suit the box. You need to check out the thickness of the steel tube which links the diaphragm and the rear suspension. For prototype work the tube was sometimes filled with 'Plasticene' to vary the mass.