Celestion Ditton 551's

I've recently bought a pair of 1970's vintage 3-way Celestion Ditton 551 speakers off ebay (£50). They weigh 25kg each, and have 12 inch drivers. Does anyone have any knowledge of this model?

I am also in the process of buying a Quad 405-2 amp for these (£150), and need a pre amp. I have been told a Quad 44 would be a good match, but these seem to go for £200+. Can anyone recommend other pre-amps for this set-up, or give any other advice? Thanks Rob

 

I've got a pair of 442's - which were the little/big brother /successor to the 551's - although they're now in storage.

The bass on my 442's was stunning - according to the little leaflet I've got here describing the 551, 442 and 662, 330mm/13" bass driver in a sealed box (which to my ears was always superior to a vented box. Your 551 is specified as 290mm (11.4") and is vented box so YMMV.

Over the years I found the treble harsh, especially (I suspect) with the loss of the little perforated covers over the tweeters, and that's the major reason why they were retired.

Stereo imaging struggles because of the design of the front baffle. The front baffle is rebated slightly behind the front edges of the cabinet, which I don't believe helps treble dispersion, and in any case imaging (well, almost everything) was dramatically improved (to my ears) by removing the grilles - thick pieces of chipboard that made the rebating way worse.

If I was looking for matching equipment, i don't think I'd be looking at the Quad 405. (but then I don't think I'd ever look at the Quad 405). Although I've never heard one, the Quad was the amp that started the pain of DBTs back in the 70's. You can read about it at Stereophile

I think you need a smooth amplifier for these speakers - I suspect the 405 won't fit the bill - or new tweeters. As it happens (completely unconnected with the Stereophile article) I used to have (okay, I still have, but in need of repair) a Lecson AC1 AP3 combination. The lecson power amps were beautifully smooth and effortless. back in the 70's virtually every amp was rolled off at 20kHz, so I'd start by trying a something with a softer 70's sound - a good old NAD would get you started. Where you go from there is up to you. If I think back, I think the point at which I started disliking the treble was when I purchased a Meridian 101MC as a moving coil preamp which replaced my Lecson AC1, but was never a nice treble.

At the back of my mind I want to rebuild the 442's - even if only as a pair of bass units, but I suspect this will never happen. And why did I have a pair of 442's? because I won them in a competition in a hifi mag - HiFi for Pleasure IIRC.

PM me with your address and I'll send a photcopy of the leaflet.

 

These two issues can be related, due to edge diffraction, which would be exacerbated by the rebated front baffle. You could try surrounding the tweeter with 1/4'' thick (natural) felt in an ellipsoid or diamond shape - if you can find some. Otherwise there is always Russ Andrews* 'Focus Rings'.

*Apologies for using such language!

 

Totally agreed. Overall I believe better can be achieved by building the speaker correctly in the first place - especially a narrow baffled treble (and midrange - come back Kef 104, all is forgiven...)

Try moving a TV forwards & backwards between a pair of stereo speakers - has a dramatic effect on stereo imaging