KEF 103.2 crossover upgrades

[Deore2010]

I listened to a vintage Japanese three-way acoustics from one music lover: Trio, coral x-iii, sony ss-g55. There was no three-dimensional picture on any acoustics. The sound is good, but flat and smeared. Now I assume that this is due to the inconsistency of the crossovers. This is especially critical on three-way systems.

 

[jnoyes]

Can someone show me how to bypass the protection circuit?

Thanks

 

[leesonic]

Can someone show me how to bypass the protection circuit?

Thanks

Easy or hard?

Easy : bridge the poles of the relay with a piece of wire

Hard : remove the components of the protection circuit, and bridge where the relay poles were

 

[jnoyes]

Bridging is fine, can you show me the where the poles are?

 

[leesonic]

Bridging is fine, can you show me the where the poles are?

The short white wire you see where the relay RL1 used to be is bridging where the poles (contacts) were.

 

[jnoyes]

The short white wire you see where the relay RL1 used to be is bridging where the poles (contacts) were.

Thank you so much!

 

[bad_boo]

Answering the question you posted on my profile, you can disable the protection circuitry by removing the relay and jumping across the contacts with a short length of wire. You can also remove the two thick film modules, and the leaky old caps, and there are probably some resistors too. Check back at my pictures in this thread, things should become clear. One advantage of removing the protection circuit is that you can run the tweeters without going through the 300uF caps for the woofers.

Lee.

Hi Lee,

I just picked up a pair of KEF 103.2, and of the speakers has no relay and some other components. After doing some research I found your comment and I was wondering if that is exactly like my case? as per picture below.
(the other speaker has all components and relay).

Thanks

 

[bad_boo]

I just recap and upgraded the crossovers on my kef 102.3 speakers.
I tried to keep it on budget so I ordered MKP capacitors from aliexpress. Around $30 CAD for all of them. All working well and sounded good, and just waiting sometime this week to give a proper test when I'm alone at home.... but I can say it was a success.


I also followed the values as per this comment below, on this thread. Thanks for that!!!

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

 

[leesonic]

I just did another pair of these crossovers for AK member @MCAUDILL . They had the same corrosion on the PCB that was causing one of the woofers to drop out.



When working on these crossovers, I always pull the relay and clean the contacts.



Here they are completed. Since Erse Audio are pretty much dead to me, I used Dayton Audio film caps from Parts Express, plus their own brand of electrolytics. The protection circuit caps were just some Nichicon PWs that I had in my spares box.



Lee.

 

[StimpyWan]

I just did another pair of these crossovers for AK member @MCAUDILL . They had the same corrosion on the PCB that was causing one of the woofers to drop out.

View attachment 2870797 View attachment 2870798

When working on these crossovers, I always pull the relay and clean the contacts.

View attachment 2870800

Here they are completed. Since Erse Audio are pretty much dead to me, I used Dayton Audio film caps from Parts Express, plus their own brand of electrolytics. The protection circuit caps were just some Nichicon PWs that I had in my spares box.

View attachment 2870801 View attachment 2870802

Lee.

Nice work...!

Also, after the death of the owner, Erse Audio was bought out by it's former employees. As such, Erse Audio lives again, as US Coils. Pretty much all the Erse inductors and capacitors are available again. A good source of parts.

 

[leesonic]

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.

Do as I say, and not as I do. I was just checking back through this thread for some pictures. I have a pair of 101 crossovers to be reworked, and of course, I order the parts before they arrived. Now I need to place another order, $10 worth of parts, and $10 shipping.

 

[BilboBaggins]

Do as I say, and not as I do. I was just checking back through this thread for some pictures. I have a pair of 101 crossovers to be reworked, and of course, I order the parts before they arrived. Now I need to place another order, $10 worth of parts, and $10 shipping.

Murphy has a way of sticking his nose in things, especially when we assume anything. I was thinking the same thing today. My wife is helping her son and his girlfriend move today. Everything went so smoothly in preparing for the move, so I was wondering this morning what is going to go wrong? Sure enough, they get the movers over to the new place and the tenant in their new place refuses to move. Technically he has until midnight tonight, but he had promised he would be out by 3 PM today. So now my wife has to pay for storage of their stuff overnight, and again for moving tomorrow. Sure enough, Murphy stuck his nose in there.

 

[Boba MosFET]

Nice work...!

Also, after the death of the owner, Erse Audio was bought out by it's former employees. As such, Erse Audio lives again, as US Coils. Pretty much all the Erse inductors and capacitors are available again. A good source of parts.

I don't think thats what happened.

After you posted the US Coils info I checked that site out. They showed PulseX caps proudly, with the logo I was familiar with. The prices were very close to the old Erse Audio site. I figured I'd be good to take on some more speaker projects. As recently as 10 days ago the Erse/PulseX info was still there. But I just went to the site again and its changed. Now the front page says "We offer high quality polypropylene and electrolytic caps from JB Caps".

Even though the info still says "Premium metallized film PulseX Cap with black flame proof tape and gold silk screened permanent ink." the PulseX logo is gone and these caps now says "MPX Premium Film Cap". The prices have gone up significantly.

I just looked for JB Caps, and the only company site I could find was in Taiwan. I

Unless you have info to the contrary I think US Coils is just a dealer for JB, and PulseX is just name JB used for a few months to draw in new customers. I'd really like to be wrong about this because Erse PulseX were my favorite film caps.

 

[Gwam]

I just recap and upgraded the crossovers on my kef 102.3 speakers.
I tried to keep it on budget so I ordered MKP capacitors from aliexpress. Around $30 CAD for all of them. All working well and sounded good, and just waiting sometime this week to give a proper test when I'm alone at home.... but I can say it was a success.
View attachment 2680973 View attachment 2680974

I also followed the values as per this comment below, on this thread. Thanks for that!!!

Excuse my ignorance (I'm a complete novice) but when you put the the two caps in parallel to get as close to the value of the original cap, are you just soldering the the two smaller caps onto the same hole in the circuit board?

 

[Boba MosFET]

With this thread bumped, I need to update my comment about the Erse / US Coils topic. I spoke with one of the folks at US Coils who verified the staff there were all previous Erse workers, but no details about whether it was a buyout or whatever else it could be. They're no longer carrying Erse film caps because they found JB caps were higher quality. I asked if they were made in the USA like Erse, and I was told BOTH brands were made in China. I had always been under the impression that the Erse film caps were rolled here. Imagine my surprise.

I recall reading a review of Erse caps on one of the other sites, maybe the Klipsch guys or EEVb, where one of the members tore some Pulse caps apart and pronounced the construction as cheap and sketchy. And yet the speakers I have renovated with their components sound beyond excellent. I'm sure if I'd spent $10k on Duelunds it would have been much better, of course.

If the JB are indeed "better" (and I have no idea what metrics they're using to make that call), then the only thing I can say is I hope the JB folks start expanding their line to include all the unique sizes that Erse used to offer.

 

[Boba MosFET]

Excuse my ignorance (I'm a complete novice) but when you put the the two caps in parallel to get as close to the value of the original cap, are you just soldering the the two smaller caps onto the same hole in the circuit board?

I would say thats impossible to do in most of the boards you'll run into. In the projects I've finished I put the largest cap in the board location, solder it down, and also run a bead of hot glue between the cap body and the board to lock it in place. Then I take the smaller cap and hot glue it next to the big cap, or on top of it. The leads on the second cap are wound around the leads of the first cap and soldered in place. Trim off the excess lead wire. I've done more than a few crossovers that way.

 

[Gwam]

I would say thats impossible to do in most of the boards you'll run into. In the projects I've finished I put the largest cap in the board location, solder it down, and also run a bead of hot glue between the cap body and the board to lock it in place. Then I take the smaller cap and hot glue it next to the big cap, or on top of it. The leads on the second cap are wound around the leads of the first cap and soldered in place. Trim off the excess lead wire. I've done more than a few crossovers that way.

Thank you, that's very helpful

 

[Gwam]

I can't seem to find any axial poly caps at 300uF. What about just using an electrolytic for these two 300uF caps, and polys for the rest of the board or would I be better getting two 150uF polys in parallel as above?

 

[Boba MosFET]

I can't seem to find any axial poly caps at 300uF. What about just using an electrolytic for these two 300uF caps, and polys for the rest of the board or would I be better getting two 150uF polys in parallel as above?

I did parallel poly caps on mine, and I'm glad I did. The sound turned out to be so much better than what I had before the refurb. I just tried to find pictures of the job so I could show you how I attached everything but I guess I either deleted them or completely forgot to take any.

 

[bad_boo]

Excuse my ignorance (I'm a complete novice) but when you put the the two caps in parallel to get as close to the value of the original cap, are you just soldering the the two smaller caps onto the same hole in the circuit board?

I solder their legs together and the biggest cap with the largets legs, is the one going into the wholes of the board.