KEF CS1A Build.

[DarrenHW]

It’s been a while since I last posted anything of substance, but after a considerable hiatus I’m turning my attention back to the system. As some of you may remember I picked up a pair of KEF Kit 3’s a mere 5 years ago (https://theartofsound.net/forum/showthread.php?38015-KEF-Concerto-any-good) and the time has eventually come for the project to continue.

As eluded to in the title, I plan on using the T27 & B110 in a CS1A build and incorporating a “helper” either using the B139’s or a sub. I’m in the process of putting a parts list together and would like some opinions / advice as to capacitor choice.

The tweeter network specs 3.3uF (C4) & 7uF (C5) Electrolytic with 0.33 (C3) Polyester bypass. My question is whether I should follow this or whether better results would be achieved by replacing C4 & C5 with polys? If this would be preferable, then am I right in thinking this would also negate the need for C3 as a bypass?

All thoughts gratefully received.


LINK TO SCHEMATIC https://theartofsound.net/forum/attachment.php?attachmentid=14707&d=1431426950

[Marco]

Dazza, you have a PM!:cool:

Marco.

[DarrenHW]

I've decided to stick with the XO the way Kef designed it, electrolytics and all.

Order placed, 3 week lead time on the coils :(

[Made in 1968]

Aint Falcon got owt regarding the X Over

[DarrenHW]

More than likely, but I'm not the biggest fan of Falcon's "we'll get back to you if we can be arsed" business model.

Rolling my own means I can use a size of board that works for me and allow for better coil spacing and positioning, it's all part of the fun.

[Made in 1968]

Aye ive had that particular service before.

[lilolee]

Those KEF XOvers were built to a price. I would have taken the opportunity to upgrade the caps to something nicer such as https://www.hificollective.co.uk/components/m_cap.html

I did this a few years ago and it helped open up the sound.

[DarrenHW]

Agreed.

My order is with HFC, Mundorf E-Caps, Jantzen iron core inductors for the mid and an air core for the tweeter.

The Alcaps really put me off, to my ears the Mundorfs are much nicer and the price difference is negligible.

[Made in 1968]

Im a big detractor in changing Original inductors in vintage gear

[DarrenHW]

I don't have the original inductors, so that ruled out using them. All values are as spec'd, I just opted for an air core for the tweeter as the price difference was tiny. It can only be a good thing, right???

[Made in 1968]

Well if its not a complete Classic speaker i guess there is not harm in new X Overs.

Yeh Air Cores are generally chosen for High & Ferrite for mid/Low..

[DarrenHW]

I'm glad we agree :)

[lilolee]

Yeah, didn't change my inductors, but I understood that Air Core Inductors didn't saturate so easilly and were therefore more linear. Does this translates into a better sound?

[Made in 1968]

Never hammered any speakers enough to notice any saturation..