Recapping Mid Tweeter in KEF 105.1? Total newbie here.

[mpemulis23]

Hello, all!

I'm a complete noob to all this, so please forgive me if I ask seemingly stupid questions (because I'm sure they are). I recently started taking my sound experience a bit more seriously and bought a pair of KEF Reference 105.1s. They're gorgeous. Everything seems to work well except for the mid tweeter on the A speaker. I checked the caps and one seems to be a little leaky. I'll look at the the other later to make sure this is the case. The problem is that I've never recapped anything in my life. I don't want to mess this treasure up. Is there a good tutorial out there for replacing these caps? Before I do any of this, I'm also going to take out the tweeter and inspect the connections; truth be told, I'm afraid of doing this as well.

The one clear thing I know is that all the caps need to be replaced anyway. I've heard Falcon Acoustics have great replacements, but is that the only option? This is their page: http://www.falconacoustics.co.uk/kef-105-1-replacement-capacitor-set-alcap-100v-5.html. Also, what's the difference between 2% and 5% tolerance? Any recommendation either way?

http://audiokarma.org/forums/index.php?threads/restoring-kef-105-1-speakers.430179/page-6 This user utilized some massive-looking caps that I know nothing about. Are they necessarily better than the ones from Falcon? Would I lose the "original" sound?

And final questions: is an Adcom 545 mk1 powerful enough to power these puppies? From what I've seen and read about my amp, it's a bit of a beast. My current preamp is an Adcom GTP 400; this I definitely know is not enough for the 105s. I was thinking of going with an NAD or a Hafler. Any recommendations on an amp/preamp combo? I welcome any and all suggestions. Thank you so much!

 

[saabracer23]

When I recap I usually always use poly caps, but when I did my 105.1s I did the electrolytics from falcon. These speakers were so finely tuned within the crossover that going with caps that have a lower ESR like poly caps will alter the sound a little. You could add some resistance in series if you'd like though. Plus poly caps can get big. And since they were so finely tuned go with the 2%. Even though the stock say 10% tolerance, KEF measured every single cap for these speakers and divided them into specific value piles so the tolerances are actually much tighter. The job overall is quite easy.

Dan

 

[toxcrusadr]

I'll defer to the KEF experts as I had no idea these had electrolytics in the first place. One thing I would suggest is, if you haven't soldered before, practice on some junk boards if you can. Also, if you'd rather not disturb the traces on the board, you can snip off the old caps (ONE at a time!) and connect your new cap leads to them, leaving the original wire connected to the board. Get a cheap hemostat to clip onto the lead between the cap and the soldering location, to avoid overheating the cap. You can do it!

 

[saabracer23]

It's not too hard to do the job, just need a decent iron and some solder wick. The advise above is good. When I started soldering I went to goodwill and bought a $10 Sony receiver. I turned it on and used a few of the functions to make sure it worked and then went to work on pulling several components. I pulled probable 30 caps and resistors in total, documented where they go and then put them all back in. The receiver worked great so I know I did the job and donated the receiver.

I talked with the owner of Falcon acoustics and he used to work for Kef in the day and strongly suggested against poly caps as they were originally voiced with the electrolytics.

Your amp should be just fine. They aren't the most efficient speaker in the world, i power mine with a Classé CA-400 which does 400 wrms at 8 ohms and it's a great combo. I doubt I'm even close to stressing the amp so yours should do great.

Dan

 

[mpemulis23]

I did the electrolytics from falcon.

Thanks! I'll give this a shot then.

practice on some junk boards if you can

I definitely will practice before starting this.

I doubt I'm even close to stressing the amp so yours should do great.

That's good to hear. Although the caps should probably be replaced in the Adcom, I've heard it's still fine to keep the current ones because it's the mk1.