Eric Mannon
New Member
Thanks. I got that one figured out. It's part of the protection circuit.
KEF 104/2 restoration and crossover recap
- Thread starter leesonic
- Start date
I just did another pair of crossovers last night for @ApexMonster.
They went from this :
to this :
to this :
They went from this :
to this :
to this :
nj pheonix
Lunatic Member
The originals are electrolytics. Certainly past their prime. Some suggest buying the exact same cap. IIRC the date codes on the new ones were the same as the originals. A strong case can be made to go the route these went.
Lee's done enough crossovers where I respect his judgment
Lee's done enough crossovers where I respect his judgment
BobbyN
Well-Known Member
I get that, but... was there any symptoms as far as sound that told you the caps needed replacing? Or was it strictly the age of the caps?
I've recapped two pair of the 104/2's, and could not hear any difference. I'd do it again though simply due to their age. New fluid in the tweeters did make a difference.
Likewise - replaced the tweeters with MidWest Audio MT-1191 tweeters 10 years ago - night and day. I hadn't realized how bad things had got until I looked at the room correction data on my receiver's effort to improve the sound. This excellent thread is making me think I may need to take further steps.
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)I found those two small orange caps had leaked, i mean physically leaked, and corroded the pcb. I paid $6.50 to DigiKey and bought new caps for both speakers. Then I cleaned up the corrosion on the board. A part of the circuit was reading 2000 Ohms! I used a piece of 1/16" solid copper wire to repair the trace. For the other parts of the trace that had corroded, it was easy to connect the legs of the new capacitors to each other, bypassing the the trace that was 'gone' and I mean gone.
While apart, I did do the ferro fluid replacement and it was a very easy and straight forward process. The fluid, being magnetic got 'sucked' right into the cleaned out slot in the tweeter base.
The reassembled speakers sound fantastic. I was tempted to change out all of the electrolytic caps until I realized what it would cost and the trouble with finding them in the first place. My speakers sound fantastic and I'm not missing anything!
Is it possible that you might be able to shoot me a clear shot of that white paper with all of the caps' listed on it? I'd like to take a shot of locating a source of off of those here in Canada... Much appreciated. Andrew
A friend of mine bought a beautiful pair of walnut 104/2 after hearing how my restored set sounds. Unfortunately, I didn't think to warn him to look in the woofer cavity.
This might be a problem....
He sent that pic after he brought the speakers home that evening. I just asked him if that mark on the bottom half is a piece of the donut material, or if it's a break in the driver surface.
Even if it's not, and we can put new driver material in there, it may not be possible. I understand these woofers cannot be reconed, and there are no new replacements. True?
This might be a problem....
He sent that pic after he brought the speakers home that evening. I just asked him if that mark on the bottom half is a piece of the donut material, or if it's a break in the driver surface.
Even if it's not, and we can put new driver material in there, it may not be possible. I understand these woofers cannot be reconed, and there are no new replacements. True?
That looks like a piece of the donut / middle material.
What he is seeing is "normal" for that speaker. I also have 104.2's and had to remove the drivers and the old material and re-do the donuts. He'll also end up redoing the ferrofluid in the tweeters (contact me on that one, I have loads of it from Ferrotec Inc.) and he'll wish to closely examine the capacitors on the motherboard inside the speakers and decide if he wants to replace capacitors while he has the speakers open.
There is a KEF 104.2 FB site that he'll want to join in order to learn about the tasks ahead of him...
Great speakers once they have been rehabilitated, but definitely not one for folks adverse to detailed rebuilds...
Andrew
Thank you for the info. I'll be handling the crossover work so thats not a problem. What about resources for those of us who aren't FB members?
There are a load of YouTube videos on replacing ferrofluid / reconing the inner donuts on 104.2's
GD70
Lunatic Member
I've restored several sets. In both, there were issues with the bottom woofers like this where foam debris fell into the VC gaps. I tried to clean them out with no luck. With a 30hz test tone there was noise, and distortion with music. They had to be replaced, luckily I found them on fleabay. IF you end up needing to do this, and purchase from fleabay, make sure you request the TOP woofer if available, not the bottom. Good luck.
GD70
Lunatic Member
You were luckier than I was. I did both and no success.
The way I read this is the inner edge of the donuts are glued to the center first, with sockets holding them in place, and then once those cure the drivers are raised up with your pencil and rubber band method so the outer edges can be fixed to the driver cones.
Did I get this right? And I apologize if someone else asked this in the thread, I did a fast read and didn't see the question brought up.