Kef Corelli speakers

[Richard]

Hi all,

Setting up a second system and enjoying the JR149s powered by the old Quad 33/303 earlier this year set me looking at other speakers I missed all those years ago.

As mentioned, the good lady had Corellis when we met and being of a similar age and using Kef drivers (the Corellis not her ) they had come up in search threads quite a few times.

I love the sound of the JRs at low volume and the T27 tweeter in particular has great resolution. So when a pair of Corellis came up 10 miles away a few weeks ago I bought them if only for old times sake.

Like the JRs they too are from 1979 and use the T27 but this time in a cabinet twice the volume and with the larger B200 mid/bass driver so hopes were for a little more bass weight.

They were one owner in decent condition so I planned similar work to the JR149s; remove the drivers and crossovers, check them, rebuild, clean and oil the cabinets keeping them as original as possible.

Light rust on the driver screws suggested damp but it was superficial and cleaned off with no other damp problems or the dreaded water rings on the tops. Another bonus was finding the grilles were perfect so nothing to do there either other than hoover them! Nice to find the driver date labels all matching for 1979 and the crossovers original though the capacitors don't usually hold up after 40 years.

A meter on the terminals showed one good as expected around 7R but gave erratic high readings on the other. No scraping sounds though so onwards and upwards...

[vinylspinner]

Nice speakers, had a set back in the day, traded them in against the Kef 104ab, they had the T27 tweeter too, if I recall.

Nigel

[Richard]

Hi Nigel, ah, 104AB are a classic! Do you remember how they sounded compared with the Corelli? I'd like a pair some time but they're a bit big for where they need to go in this room and I think the bass may be too much against the wall. I heard them in the past on stands out from the wall and thought them very nice indeed.

Kef never seem to have mentioned it but later Corellis also had the AB crossover. I don't know when they changed but certainly by mine in early 1979. Checking the old caps on mine showed several reading very high, 3x on a couple of them, so I changed them all. I checked the inductors, drew out the circuit, and did one at a time as I couldn't find the AB version on the web, only the earlier one.

Along the way I found the nuts holding the tags on the input terminal were only finger tight. Cleaning and tightening them fixed the erratic terminal resistance reading and both now check at 7R5.

There are larger values in this crossover than the JR149 so this time I went for the Vishay polyesters for the tweeter feeds and Mundorf Ecaps for the rest. Alcap replacements are in short supply and the Mundorfs have good specs so I went for Plain (which are Low Loss using plain electrode foils) and Raw, which are the more compact etched foil for the 30uF position, in the same way as Kef used LL and standard Elcaps.

[Richard]

And so on to re-assembly. The cabinets are solid and heavy affairs contrary to their svelt looks. They are thick c. 15mm chipboard with a full brace inside. There's heavy bitumen damping on the walls and they're fully lined with thick foam. I gave them a gentle clean and a couple of coats of Danish oil which brought them to life.

The stands were a lucky find off eBay being 15" high and the exact top plate size for the Corellis; an inch smaller in each dimension. What or who made them I don't know but they're certainly strong and heavy. I fitted screw plastic feet which made them quick to set up in the same place as the JR149s and had a listen. (The room is 12ft wide, the tweeters are 2m apart and 3m from my ears.)

Lovely, full bodied but very detailed sound. Excellent on voice, clearly showing different presenters at different times of the day on different miking. Great on classical music but equally good on pop and rock. I suppose a good speaker is a good speaker and they don't need the music to hide any shortfalls or colourations.

After 3 weeks I'm still very pleased, they're similar to the JR149s but deeper bass and generally more dynamic sounding at high or low levels. One thing I particularly like about these two speakers is that they can be played at modest domestic volume and still be a satisfying listen. I haven't even tried the tone correction on the amp. The amp just loves these speakers as it is. Most likely they are higher impedance and an easier load than my Tannoy XT8F. The 303 works well enough with the Tannoys but other amps work better. With the Corellis the 303 just sounds so good I've not tried them with any other amp yet.

[colin.hepburn]

Hi Richard/All
Are you still looking for the Alcap replacements Caps?
I see crickwood electronics are listing values from 1uf to 470uf at 50/100 volts the 25/30uf are Jackson brand

Maybe Matthew may wish to snap up some for his supplies as well
PS seems the Jacksons are a better cap than the alcaps not getting into that argument

https://www.cricklewoodelectronics.c...vers-etc..html
And some
here https://www.falconacoustics.co.uk/al...-50v-100v.html
Hope this helps

Colin

[Richard]

Thanks Colin. I tried Cricklewood and Falcon but there are only random values left in Alcaps, so I went with Mundorf Ecaps for the larger values and Vishay polyesters for the tweeters, and am very pleased with the result.

For anyone doing the job it's worth knowing there were 2 qualities of Black/Red Elcaps; standard and Low Loss. The standard are not marked as such and the LL are marked simply LL and are much larger. 5 out of 6 in the Carelli are LL.

In the later Alcaps the blue ones are standard and the black ones are LL.

In the Mundorf Ecaps the Raw are standard and the Plain are LL.

[Yellow]

HI,

My first "hi-fi" speakers were KEF Cantor's, and the drivers look very similar. I recall the Cantors had a very shallow depth, which goes completely against the 'modern trend' grain.

Nice speakers overall though. Wish I still had them, but my Grandad bought them probably in the late 70s, so they would be a bit tired by now I guess!

Neil.

[Richard]

Hi Neil, yes indeed the specs are similar, the Cantors have shallower boxes as you say, similar size baffle but half the cabinet depth and volume.

The impedance is very amp friendly which suits valve amps or the likes of cap-coupled Quad 303 which don’t like low loads. Sound is surprisingly good and mine are on most days - playing now!

Condition is important of course but the crossovers are easily re-capped and the drivers are long-lived as the B200 has a neoprene rubber surround which doesn’t rot and the tweeters are not ferrofluid so no problems there.

[sbellradio]

There's quite a bit of information on the Corelli dotted around this forum:

http://hifiloudspeakers.info/speakertalk/index.php

[Richard]

Thanks Steve, I've not seen that site, looks very interesting