Kef Corelli SP1051 - possible fix and servicing.

[Edward]

Oh I have plenty of sealant! The good lady keeps hassling me to remedy something - but you know how it is - always something more important to do.

[spendorman]

Yes. Looks like somebody has had a tinker with them.

The furry component I believe is a wirewound resistor and will probably measure OK despite the looks, although you can change it without harm.

The bass drivers should carry the SP1063 label. Judging by the brushed on Plastiflex cone doping, those look rather like the SP1014 from the Chorale. I could be wrong, but I believe the SP1063 had a sprayed on thinner coat. I don't think there's much between them in characteristics though.

The tweeters look a bit tired, but may sound OK.

I thought that the SP1063 differs from the SP1014 by having an aluminium voice coil as opposed to the copper one of the SP1014.

[Macca]

No the main drivers are SP1063 with a date of 110276 whereas the wonky T27 tweeter has a date in 1974 so clearly have been changed.

Maybe not, KEF probably had thousands of drivers sat in stock back then, sometimes for years before they were built into a speaker.

[Edward]

All looks OK apart from this:

x 0.69 mfd (50v) 2 x MA684k 630v

I'm not sure what you've been given there.

The value is 0.6uF. I used 0.56uF which is close enough. I have plenty of spares.

That schematic is wrong by the way.

been researching why I was given a capacitor with seemingly strange markings. But all is clear when I look at this reference.

So basically 684k means 0.68uF with 10% tolerance. (68*10,000 / million = 0.68uF with 10% tolerance).

[walpurgis]

Oh well. You have a couple of 0.56uF on the way, which are quite small, so may be easier to mount.

[Edward]

Indeed - the ones I purchased are significantly larger than originals. No doubt due to the high 630v rating when 50v was all it needed.

Once I have yours (many thanks btw) I will sit down and work out best way forward on the caps - and resistor.

I'm assuming the inductors will not have perished - all my reading indicates that these typically are the last to perish.

[walpurgis]

The inductors should be OK unless somebody has put ludicrous power through them, but the drivers would blow first anyway. I've never found a dud inductor in old speakers, not even sixty year old ones. It can happen though.

[Lawrence001]

Some of the Kefs I've recapped use low loss caps on the treble, do any of your caps have LL on them or similar? Some people recommend changing these to polyprops but opinion is divided as the lower ESR could increase output. Ie smoother but too bright, or swings and roundabouts.

Sent from my BLN-L21 using Tapatalk

[Edward]

Some of the Kefs I've recapped use low loss caps on the treble, do any of your caps have LL on them or similar? Some people recommend changing these to polyprops but opinion is divided as the lower ESR could increase output. Ie smoother but too bright, or swings and roundabouts.

Sent from my BLN-L21 using Tapatalk

Nope nothing like that. Just bog standard caps so far as I can see.

Cricklewood essentially had only two types Alcap and Ansar. The Ansar caps were £5 each and upwards and given that this project is only for fun and learning I went with the cheaper Alcaps. Still the caps cost me slightly more than twice what the speakers costs me. Hopefully things will work out in which case I will do a light sanding and then Danish oil.

I'm away tomorrow so realistically it will be earliest Monday when I do the work.

[Lawrence001]

They will definitely benefit from a recap the only question is by how much. Usually it's night and day and you realise that when people describe vintage speakers as warm and cuddly they are really describing the effect of the dried out caps.

PS I've installed music monkey, deleted AVG which was driving me nuts, switched off all the autostart bloatware that's built up on my laptop and I'm ripping to flac in about 4-5 mins now

Sent from my BLN-L21 using Tapatalk