LS3/5A crossover part

[mcintosh amp cloner]

Hi

I just logged back into DiyAudio after 7 years when I suddenly realised I had an account on here and this forum might be helpful!

I bumped into it today from Google!

I am self building LS3/5A with Kef woofer B100, Kef tweeter T27 which are available around £100 - £150 for both or can buy Kef Chorale or Kef Celeste with the parts included around same price used on ebay and they are originally used in LS3/5A.

The cabinets i might self build using wood and glue or might purchase available from China on ebay new condition around £150 includeds all the velcrow, speaker covers, wood veener, gold speaker connectors, damping foam etc to make it look 100% like LS3/5A.

Now the crossover I can build using diy curcuit board, capacitors, resistors but there is parts on curcuit diagram I am not familiar with can someone tell me the parts I put in 'SP' areas i'm assuming its transformers which I am not very familiar with.

Can someone tell me the exact thing to type on ebay to find it.

I understand the SP areas that say HF in, LF in, B100, T27 (obviously).

So a LS3/5A build around £350 even though they sell £1500 - £2,500 on ebay. Fan boys all paying for the brand name BBC and the history.

Circuit diagram attached.

Shall I make a video to put the build on youtube?

Anyone want to donate a Kef Chorale / Kef Celeste? Lolz.

 

[mcintosh amp cloner]

The SP's are only in the tweeter section, if its a transformer exactly what is its function?

Can I by pass this part by connecting the SP's together?

I'm assuming they are transformers because a google image search of LS3/5A crossovers show transformers on them.

 

[Andersonix]

"SP= SOLDER PIN"

You're looking at a tweeter attenuation L-pad.

Transformers, you say? They wouldn't be inductors L1, L2, L3 etc.? You're not going to go hurt yourself now are you...?

 

[mcintosh amp cloner]

What do I put at SP - solder pins?

Which solder pins do I connect to where?

 

[levistubby]

I seem to remember that there are different versions of Kef B200 and T27. Only the correct versions will produce the intended end result in an LS3/5A copy.

 

[chrisb]

yes, a storied past that design

 

[scottjoplin]

Falcon acoustics will probably be able to help you

 

[mcintosh amp cloner]

Yes there are different versions will double check them before purchasing seen one say SP100 on it.

At the end of the day the versions will have pretty much no visible difference and sound difference will probably be too hard to notice. As long as the main sound is there.

I have a feeling LS3/5A probably sound very average to start with.

I had Kef Concerto with both T27 & B100 and it did not sound anything speacial.

In fact the huge port next to the bass driver is the most stupidest thing I ever seen, whats the point of having a big cabinet when a massive hole next to the woofer let all the air escape.

Thats exactly how the bass sounded like the air was escaping.

 

[mcintosh amp cloner]

Recieved email from Falcon Acoustics early today he said 11 ohm version does not have transforners just usual inductors as labeled on the diagram.

I asked him what exactly do I do with the SP - solder pins but no response yet. Its not transformers like i thought and if I leave them empty the positive side from amplifier will not connect to tweeter positive side so no sound as can see in the diagram.

I am now assuming SP's connect with one another.....

 

[Andersonix]

...to create the desired tweeter attenuation

 

[scottjoplin]

You're not going to go hurt yourself now are you...?

I'm more concerned for the T27

 

[mcintosh amp cloner]

Andersonix - Thank you for that but I dont know what that is.

It does look like some tweeter control.

So when I make the cross overs do I just end the current journey at the SP points like a dead end road?

 

[mcintosh amp cloner]

I'm more concerned for the T27

Thank you for your concerns.

See my other thread, completed 2 Bang & Olufsen Beovox Restorations today.

 

[rayma]

the versions will have pretty much no visible difference and sound difference will probably
be too hard to notice. As long as the main sound is there. I have a feeling LS3/5A probably
sound very average to start with.

It appears that you are building this speaker to sell, based on looking like the original and not on sound quality.
If so, this thread should be in Vendor Forums, and you should state you are soliciting advice for a business.

 

[mcintosh amp cloner]

Falcon acoustics have informed me it is a resistor ladder i am considering by passing the whole lot and miss out the resistors in that section. The 15 ohm version of LS3/5A do not have this bit.

 

[mcintosh amp cloner]

In fact I just got my self a brilliant idea.

I got the 15 ohm LS3/5A crossover diagram it is plain and simple will just build that one.