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KEF 103.2 crossover upgrades

Well this looks like an interesting project. I have a pair of 103.2 here that could use some attention. The cabinets are beautiful but the sound is lifeless. I was going to sell them off, but after reading this thread I'm interested in reviving them. I'm confident they can shine with the right parts.

Check out the work the guy in Bulgaria did:

https://www.ebay.com/itm/KEF-reference-103-2-refurbished-and-rebuild/264975808175

I tried to read both his cap list and the info in the pics but neither one was much help. He shows 8 caps in his parts list, but there's 10 films and 6 polarized in the pics, so I'm not going to rely on his list. If any of you guys have a cap value list you can post I'd really appreciate it. I'm going to place an order for Mundorf caps as soon as I can figure out which values I need.
 
Boba MosFET said:
If any of you guys have a cap value list you can post I'd really appreciate it. I'm going to place an order for Mundorf caps as soon as I can figure out which values I need.
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The schematic is posted on page 1 of this thread. Just order the values from that. Or check what your crossover has, and order those.
 
leesonic said:
The schematic is posted on page 1 of this thread. Just order the values from that. Or check what your crossover has, and order those.
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I noticed there were two different 103.2 boards represented in this thread, do both boards carry the same values?
 
Boba MosFET said:
I noticed there were two different 103.2 boards represented in this thread, do both boards carry the same values?
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That's why you should always check what your crossover has. It's the same for amplifiers and stuff, often there are values that differ from the manufacturers schematics.
 
leesonic said:
That's why you should always check what your crossover has. It's the same for amplifiers and stuff, often there are values that differ from the manufacturers schematics.
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I agree, and after my first few mistakes I've learned to do that. I really was just looking to see if any capacitor values changed between the two boards; i.e. did KEF change caps for later boards, or were the later boards simply better design and/or materials?
 
After a delay I'm ready to move on my cap order. I have the following to choose from:

ClarityCap PX
ClarityCap ESA
Mundorf MKP

I can get all the poly caps from any one of those three vendors with the exception of the 7uF, which is going to get scabbed together out of either 6.8 + 0.22 or 3.3 + 2.7 +1, so I'd like to hear from anyone who favors any of those three or has any objection to them.
 
Hi @Boba MosFET how did you get on with your recap?

I've got two sets of these 103.2s and absolutely love them! I had one set originally and quickly bought a second as a spare. The bass is nice and tight and overall a nice warm sound. They don't sound as dynamic and bright on the top end as some modern speakers but I do enjoy listening to music on these, they always seem to make me want to crank the volume up.

Anyway after reading @leesonic fantastic thread on a recap with erse film caps it got me thinking if I was actually hearing the best out of these speakers. Particularly with regards to the mid and top end. I've only had them both for around 5yrs and since they are now approx 40yrs old, I thought I might try the same recap.

Initially I took the crossovers to my local electrical engineer (who is fantastic by the way) and he checked the original alcaps and found them all to be in spec (10% tolerance). He fixed a couple of bad tracks that had corroded and some caps on the protection circuit which had leaked.

So I've now tasked him with the project of making me two new crossover boards with film caps as per leesonics suggestion and minus the protection circuit.

I'm thinking of going with clarity cap csa as they seem from what I have read to be of good price/performance value. I'm also thinking of going with the same measurement caps as Leesonic as with modern 5% tolerance caps I'll prob be closer to the spec than the current 10% lytics. I know the sound will change but I'm hoping for the better.

Be good to hear how you got on.

Oh I've attatched a couple of measurements my engineer took of the crossovers once he checked them over and it was great to see how well matched they were even after 40yrs! The crossover point seems to be around 1.4khz as can be seen from second pic.
IMG-20210501-WA0003.jpg IMG-20210501-WA0002.jpg
 
Hi Amo, I've gotten no closer to doing this upgrade so far. I've been too distracted by all kinds of deals I keep finding, and projects that friends set on me. I've upgraded a few amps and preamps and I'm only now getting set to do the KEF rebuild. I think mine sound excellent but the bass out of them is very limited. I'm going to go with the Erse caps, which I didn't want to do because I've read bad reviews of their construction quality on the Klipsch site, but they're the only company I can get some of these values from. I'm going to replace the Alcap 300uF with a new axial electrolytic and convert everything else over to PulseX film caps. That should be better than doing nothing, and better than just going with all electrolytic. I'm going to complete one crossover and try to do an A/B test between a new crossover and the original parts by panning left-right on my system.

I really wanted to use the ClarityCaps but the supplies of those are drying up right now. I wish you luck in finding them in the values you want.
 
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Boba MosFET said:
I'm going to go with the Erse caps, which I didn't want to do because I've read bad reviews of their construction quality on the Klipsch site, but they're the only company I can get some of these values from.
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Never ever ever had any problems with Erse caps, except for the problems with shipping delays over Christmas. I think I would take any opinions on the Klipsch site with a huge pinch of salt. It certainly doesn't follow the "all audio no attitude" values of this site.
 
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leesonic said:
Never ever every had any problems with Erse caps, except for the problems with shipping delays over Christmas. I think I would take any opinions on the Klipsch site with a huge pinch of salt. It certainly doesn't follow the "all audio no attitude" values of this site.
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I know, and it was from you that I first heard about Erse so thats why I considered them at all. I'm sure they'll sound "good", but it was one discussion in particular that got me wondering:

https://community.klipsch.com/index.php?/topic/178770-erse-pulse-x-capacitors/

See, on one side of my brain there's that analytical guy who has been led down one path or another and had to learn to avoid snake oil. On the other, there's that guy who worked in an audio store and had been confronted with all sorts of snake oil (Tweek, TipToes, cork mats, oxygen isolated wire, too many other things to name) and sat in a room full of skeptical guys and found some of them worked. Some were absolutely ridiculous (remember the green CD markers?) but some really shut us up (the wire). I've been both amazed and embarrassed by finding out one way or another if something was real or not. I learned about confirmation bias and I'm acutely sensitive to it now.

To put a finer point on it: I looked at Erse because I respect your opinion. I looked askance at Erse because I read a thread posted by a guy who tore down their PulseX caps and posted pictures of it (unfortunately the pics aren't up any longer), and he also tore down their marketing noise. If what he says about their claims is true, then they really screwed up a good product by putting a marketing snow job on top of those film caps.

Nevertheless, I'm buying the parts because you recommended them, marketing-speak be damned. :D
 
Boba MosFET said:
To put a finer point on it: I looked at Erse because I respect your opinion.
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Why, thank you!

Erse caps are good value for money in my opinion. Now, if somebody contacted me and said they wanted Solen caps instead of Erse, then I would still do the job, but I would charge them more because the caps are more expensive. When I did my Polk RTA-15TLs, I used Solen caps because that was what was recommended over on the Polk forum (see my comments about about the Klipsch forum above). As it was, I incurred some wrath over there because I didn't use the exact same boutique resistors as was mentioned in the thread. You'll see some 103 crossovers on this thread that I restored using Dayton caps. This was because the package from Erse was stuck at a USPS facility, and I didn't want the owner of the speakers to wait any longer.
 
Very nice @hpyle. That rosewood finish looks plush. I've just ordered Jantzen standard caps and jantzen cross caps too. Hoping to get mine done on the weekend. What values did you use?
 
Amo said:
What values did you use?
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I tried to keep to the original values, pretty much. My cap meter shows the Solens came in all slightly under spec. For the 300u input electrolytics, I just added a small bypass (based on no real evidence of benefit). I assume that the protection electrolytics aren't critical at all, but replaced with same-value.

4.2u (treble): solen 3.9 + jantzen 0.33 parallel
7u (treble): jantzen 6.8 + jantzen 0.22 parallel
2.2u (treble zobel): solen
10u (bass zobel): solen
10u (bass): solen
 
One thing to watch: after soldering these bigger caps on the board and hot-gluing everything in place, it was really fiddly to reach the supporting bolt in the cabinet. You may want to leave lots of space around the center of the board.
 
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hpyle said:
One thing to watch: after soldering these bigger caps on the board and hot-gluing everything in place, it was really fiddly to reach the supporting bolt in the cabinet. You may want to leave lots of space around the center of the board.
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My parts showed up today, so I started building my boards. That lockdown stud was a piece of cake on the first board, but I'm still fiddling with the second one.

Since Erse doesn't have a 7uF film cap, I had to make do with a 4.3uF and a 2.7uF. On my first board I put the 2.7 in first and leaned it towards the outside edge of the board before soldering it in place and then putting the 4.3uF on top of it. That gave me room to get the nut onto the stud. But when I got into the second board I whipped through it so fast that I forgot to put the 2.7uF on the bottom, instead I put the larger cap in there first. Now there's no room to get that nut spinning onto the stud.

I'll have to pull the board again and glue the nut to the board. Then I can spin the stud from the bottom of the box using a large Philips driver (look under the black foam plug, you'll see the head of the stud, its actually a Philips embedded in the box).

These weren't too hard to build, but I'm taking my time so I don't scratch the finish. My speakers are pretty clean and have no scratches, and I don't want to give them any.

I found that one board had a leaking polar electrolytic cap, one of the 100uF 10V in the protection circuit. On the other board, it looked like a few of the non-polars were leaking or about to. They had a dusty look to some of the ends. Most of them were above the specified capacitance, some of them by a lot.

This should be interesting listening once I get these broken in. The speakers were just dead sounding before, so I'm expecting magic with all these new parts. At the very least they should sound as good as they did in our store back in 1983. We'll see.
 
I used my new Peak ESR tester to see what the value drift looked like, if any. The results follow.

Speaker 1: Speaker 2:

spkr1.jpg spkr2.jpg
 
Ok, magic happened. I wholeheartedly endorse Erse caps now. Rich detail, no grit, and instruments sound like they're floating in the air. I'm on a stock Adcom amp and preamp, with HBR music streamed off my server. These caps don't even have 5 hours on them and they're exceeding my expectations. Many thanks to @leesonic for the advice.
 
hpyle said:
I just recapped a pair using Solen and Jantzen film caps, and Nichicon electrolytics in the protection circuit. One channel had no bass due to corroded traces. Now they sound just lovely.

View media item 25335
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Walnut and teak are the common veneers, dark rosewood is pretty rare. Those look like furniture, like a KEF speaker should look, congratulations!
Did you do any refinish work on those? With my 103.2 sounding flawless now, my attention is turning to the cabinets. The veneer on mine is perfect but the protective layer isn't. Lots of minor scuffs, especially on the tops.

@Joe Nardy - you ever think about taking on paying customers for your great refinish work?
 
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