Mystery Capacitor

[AustinPrior]

Hello Folks,

New to the forum. I've been trying to fix my JBL TLX 210 speaker. The problem was obvious: A visibly-blown capacitor. The trouble is that I haven't been able to find a replacement on-line. It's dark blue radial capacitor with the following markings:

BENNIC
BI-POLAR
6.8 MFD
50 WV

Can anyone help me?

It needn't be exactly the same but as long as it's compatible and won't reduce my sound quality, I'll be happy. I'll order two of them so as to keep the speakers as matched as possible.

I've scoured Bennic's website but haven't found it. I'm not experienced with finding parts and I don't know what the 50 WV figure means so perhaps I just missed it.

Thanks

Austin

[dave_gerecke]

Hello AustinPrior, the 50WV is the working voltage for the capacitor. I.E. dont' use the capacitor above 50volts and you should be ok with it. You could replace the capacitor with another one of higher voltage, but with the same capacitance rating, 6.8uF, and the same material type, in this case, Bi-Polar Electrolytic. Having said that, I would personally spend a few extra coins and replace it with a capacitor having the same capacitance, and the same or higher voltage, but use a better material, such as polypropylene capacitor. You should be able to find the right cap from one of the electronic components suppliers, or suppliers of speaker components for DIY speaker building.

Good luck,

Dave Gerecke

[Mooly]

Three to choose from
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[tomchr]

MFD = uF or micro-Farad
WV = Working Voltage
Bi-Polar = not polarized (unlike the schizophrenic caps... )

Basically, any non-polarized 6.8 uF cap will work as long as it's rated at 50 V or higher. I second the idea of replacing the bipolar electrolytic caps with some polypropylene film caps. Wima MKP would be a good option or any of the polypropylene boutique caps. Replace the caps in both speakers, naturally...

~Tom

[Minion]

I don"t think you have to use a NP Electrolytic , you can use any NP cap , Like a Film cap , 6.8uf might be hard to find in a Film cap but a 4.7uf paralell with a 2.2uf will get you there and a Film cap will definately sound better than a Electrolytic , but I would change them in Both speakers ....

Or what Tom said ....

[kevinkr]

I am assuming that the capacitor in question was in the X-O to the tweeter, unless it was a shunt cap in a second order network for the woofer. Usually these capacitors fail for a reason - it could have been defective or subjected to excessive DC voltage or AC current.

If this cap is in series with the tweeter it is also possible that the tweeter is damaged. Check the voice coil DCR of the tweeters in both boxes - if they are different by much more than 10% this indicates a potential problem. (Might be a good idea to check the woofers as well.)

Make sure if the amplifier is solid state that there is no DC on its output.

It could be just a bad cap, but....

I used Bennic caps in gear that I had OEM'd in Hong Kong and they seemed reasonably reliable.

Note that bi-polar electrolytics may have significant ESR/ESL which the film cap will not. If things do not sound quite right with film caps installed inserting a very low value resistance in series with the cap should help. I would expect nothing over 1 ohm would be required, and probably not at all.

Film caps should in most cases sound better than inexpensive bipolars.

Note that not just any bipolar lytic will work despite what others have said here, check the current ratings and choose a part expressly designed for use in cross-overs. IMO A 6.8uF film is really the way to go.. Clarity makes good ones IMHO.

[wintermute]

partsconnexion has 6.8uF axon polypropylene caps for $1.99 each. AXON True Cap Metallized Polypropylene Capacitors Though the shipping will more than likely be double or more the cost of two caps...

Something closer to home (and ironically a lot more expensive) are these from jaycar uk 6.8uF Hi Quality Metallised / Polypropylene Capacitor - Jaycar Electronics

Oh and welcome!

Tony.

[Mooly]

Polys also available,
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