|Left had example is 1968 ( one of a pair). Right hand example is 1970 model ( one of pair)|
|With original failed T27 tweeters|
I purchased both pairs from a nearby charity shop where they looked a bit forgotten. Their styling is rather dated, or possibly retro 70s depending on your viewpoint. What makes them particularly interesting is that they were one of the first speakers to use the combination of the Kef T27 tweeter and B110 mid-range/woofer. This same combination was subsequently used in the Legendary LS3/5a speaker, which i also own a pair of. I was interested to see how they compared.
Of the two pairs, the earlier 1968 pair were slightly better made. The cabinets of both are chipboard, not the ply of the ls3/5a. The 1968 unit had black grilles and a better veneer. The 1970 unit had hessian grilles and a cheaper looking veneer, though again this may be down to the tastes of that era.
With two sons of college age i decided these speakers would work well for bedroom systems, especially as they don't look expensive .
On playing both pairs i found that the tweeters were blown in the earlier pair and this was confirmed when i removed them and put a multimeter in continuity mode across the wire tabs. Both open circuit.
I decided to move the tweeters from the later pair into the earlier ones, as they were in better condition and were visually more appealing.
The 68 pair sounded very nice. Not much bass and none of the LS3/5a bass-hump but a good sound. I polished the cabinets and put these aside as the pair now working in original condition.
|Note : tweeter already removed, nut crushed under woofer|
Worse, in removing one bass unit the spiked nut which the bolt from the front engages with, started to tuen, and in the end some of the chipboard around the hole broke away.
With good advice from the always helpful diyaudio forum, especially member system7, i glued a plywood brace behind the broken hole and built it up with plastic wood. A good sand, then a quick spray of black paint and the speaker mounting recess looked as good as before. I got a new through bolt and its crown shaped nut which has spikes which pull and Dig into the wood from the back.
Next what to do about the tweeters. T27 are no longer made and command high prices. However Falcon acoustics sell a Morel CAT298 tweeter which is a drop in replacement even down to the screw hole positions, so i ordered a pair of these.
The B110 drivers had no indication of polarity, and while i had taken pictures during the strip down , i was a bit confused about their polarity. Once again diyaudio came to the rescue and i used a 1.5v AA battery , touching the two driver wires to it. I could see the polarity by way caused the speaker to push out rather than pull in.
|Using an AA battery to determine driver polarity|
|Original caps and blue alcap replacements|
|Left hand unit is one of the 1968 pair with T27. Right hand example is one of the 1970 pair both of which got new Morel cat298 replacement drivers|