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replacement crossovers: is it just Wilmslow now?
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roberte
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PostPosted: Fri Aug 15, 2008 11:47 am    Post subject: replacement crossovers: is it just Wilmslow now? Reply with quote

Now that Falcon are no longer around (I have got that right haven't I?) is it just Wilmslow that I can look to for replacement crossovers for Kefkit3s?
Just short of £120 is quite a lot - albeit for an uprated crossover - given that I'm still dithering about whether these speakers are right for me or not.
They are sounding much better on the end of a Quad 909, but still rather contained sounding.
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ColinR
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PostPosted: Fri Aug 15, 2008 3:08 pm    Post subject: Reply with quote

The recent loss of his wife Valerie has hit Malcolm quite hard, so sadly for most practical purposes Falcon Acoustics is no more.

You could try the boys to whom Malcolm sold the inductor business www.audioloudspeakers.co.uk .

If they're not interested and you can solder I can supply you with the circuit and you can then order the correct parts from whoever you wish and built a point-to-point on a piece of hardboard.
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roberte
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PostPosted: Sun Aug 17, 2008 7:10 pm    Post subject: Reply with quote

The diy approach is not a bad idea - if you don't mind some pretty basic questions along the way.

Is the circuit the original as fitted; when I was looking at Falcon a couple of years back there were various minor mods that had been made over the years.

This particular method of construction is to glue the components onto a piece of board and use their respective wires to do the connecting up - is that right?

I do posses a soldering iron and a multi meter but have never used them for much.
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ColinR
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PostPosted: Sun Aug 17, 2008 8:03 pm    Post subject: Reply with quote

You’ve got the idea behind point-to-point now, which crossover variant do you want?

Be aware the copyright still belongs to KEF and Malcolm Jones so they cannot be made freely available.

Now let’s deal with the kit which I’ll link to another question about upgrading KEF KUBEs.

25 or 35watt soldering iron for crossovers, 15 watt for KUBEs and electronics.

Blade tips for crossovers to get the heat over a wider surface area pointed tips for small electronic components.

Cored solder, a pot of plumbers flux, a stand for the iron, a bit of damp sponge (used composite kitchen scouring pads are good) and some de-soldering cord (or old aerial coax if you’re into recycling), fine sandpaper or wire wool and a very small watchmaker’s screwdriver.

THEN watch this YOU-TUBE video. www.youtube.com/watch?v=I_NU2ruzyc4

For de-soldering substitute the copper braid for the solder in the above video when removing components from crossover or electronic PCBs.

The plumbers flux is used on the joins of the point-to-point once the ends of the wires have been cleaned up with the wire wool or sandpaper, you apply it with the small watchmakers’ screwdriver.

Plumber’s flux is also used as a “dip in sauce” to keep the soldering iron tip clean.

That's all I'm going to say about soldering, to get your "eye in" get a small electonic kit (£4.99-£9.99 build it and then take it apart, then rebuild it!
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roberte
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PostPosted: Mon Aug 18, 2008 9:22 am    Post subject: Reply with quote

When I was in touch with Malcolm it was the 6c that I would have gone for; I can't find the relevant Falcon page any longer so do you know what that would have been? The other suggestion he made was the No6/33 Network Upgrade but that wasn't a drop in replacement.

The iron I have is a 12W point so perhaps a more powerful/wider iron is called for. That video is very helpful by the way.

When de-soldering does the braid wick away the solder?

I had a quick look at the existing crossovers yesterday and the wiring to and from the drivers appears to have almost no slack in it - should I be planning to replace that wiring in any case? Secondly is it worth making the new board the same size as the old one so it fits the hole in the baffle?

Thanks for all the pointers so far.
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ColinR
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PostPosted: Mon Aug 18, 2008 10:11 am    Post subject: Reply with quote

The "6" is essentially the Cambridge R50 without the Coles 4001G and offers a flatter impedance response to the standard SP1004.

12W might be a bit feeble for this job, a cheap 25W would be better.

Quote:
When de-soldering does the braid wick away the solder?


Yes Very Happy .

Quote:
wiring to and from the drivers appears to have almost no slack in it, is it worth making the new board the same size as the old one so


You might have to get some Vero board.

You'll have to contact me via the "front door" colin@hifiloudspeakers.info for the schematic, pictures of the type 6 (not for sale!) and I'll send you some .jpegs.
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roberte
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PostPosted: Mon Aug 18, 2008 1:59 pm    Post subject: Reply with quote

just been looking through your e-mails - big help thanks. Having photos to compare to diagrams makes things much easier.

More questions though - specifications for the diagram:

HP/LL is what?

and is that then followed by dimensions for standard (STD) inductors?

vero board: would be smaller and neater but a bit more fiddly to work on than hardboard?
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ColinR
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PostPosted: Mon Aug 18, 2008 3:07 pm    Post subject: Reply with quote

High Power Low Loss using 0.8mm gauge wire, you'll have to get a 0.71mm gauge on a 12mm core from Audioloudspeakers.

STD using 0.56mm gauge wire on a 9mm core.

Yup!




The terms SP/HP?STD were Malcolm Jones', in general STD 9mm core, HP 12mm core SP even bigger core. The wire gauges changed to increase the number of varients.
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roberte
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PostPosted: Mon Aug 18, 2008 4:06 pm    Post subject: Reply with quote

Reading the specification in conjunction with the Audioloudspeakers pages makes a lot more sense!

The board as supplied looks to use Alcaps - is the quoted tolerance of+/- 10% an issue here (obviously not otherwise they wouldn't have used them!) but in comparison to the closer tolerance Solens or is that a side issue compared to other (potential) benefits of polypropeline?
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ColinR
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PostPosted: Mon Aug 18, 2008 11:30 pm    Post subject: Reply with quote

Quote:
The board as supplied looks to use Alcaps - is the quoted tolerance of+/- 10% an issue here (obviously not otherwise they wouldn't have used them!) but in comparison to the closer tolerance Solens or is that a side issue compared to other (potential) benefits of polypropeline?


It's a matter of cost, like cars a Mini (I used to race them Shocked ) will get you there but an Evo8 (saw the number plate on the back of a Ferrari Very Happy ) will offer a different experience.

So Alcaps will work, but Polystrene will be more expensive and brighter due to a lower ESR, Polycarbonate and Polypropylene will be somewhere in between.
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roberte
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PostPosted: Tue Aug 19, 2008 9:53 am    Post subject: Reply with quote

and possibly last question for now...

resistors: Audioloudspeakers have 7W, 9W and 11W, your 6 appears to have 5W, 10 Ohm - so would 7W 10 Ohm be the closest?

oh, and, inductors again - all ferrite cores though the diagram shows one as not?
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ColinR
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PostPosted: Tue Aug 19, 2008 12:03 pm    Post subject: Reply with quote

Ignore the lack of two lines above the 600uH inductor, it's not an air-core in the KK3 (but it can be in the R50 Rolling Eyes ) and put two lines above it on your schematic.

A 7W resistor will be suitable Smile .
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roberte
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PostPosted: Tue Aug 19, 2008 1:23 pm    Post subject: Reply with quote

whereas the original sp1004 did use a mix of air and ferrite cores?

sp1004
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roberte
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PostPosted: Wed Aug 27, 2008 12:52 pm    Post subject: Reply with quote

Just having a look through the circuit and also trying to arrive at a parts list:

obvious query: if two components are in series it doesn't matter which order they come in? (eg L1, L2 and C2 are in series but could also be L1 - C2 - L2 as they are on your circuit board)

probably obvious query:C3 and C5 are given as 4.5uF and 5uF respectively but on your board are both 4.7uF, is this sort of difference in value irrelevant or should I aim to use values as stated if they are available?


Would it be ok for me to put a complete parts list here and ask you to double check it or would you rather I e-mail it?

Thank you

ps just been through the list and costed it, price per speaker:

appr. £45 with Solens
appr. £20 with Alcaps

at a total of £90 on parts plus making up, £115 from Wilmslow doesn't seem so over the top (assuming they use a Solen equivalent)
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ColinR
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PostPosted: Wed Aug 27, 2008 2:26 pm    Post subject: Reply with quote

Quote:
£115 from Wilmslow doesn't seem so over the top (assuming they use a Solen equivalent)



Laughing Laughing Laughing Laughing Laughing Laughing NO THEY USED ALCAPS
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