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Sand filled capacitors


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48 minutes ago, Marvel said:

Only when Dennis mentioned that they last a long time (as best I recall).

 

How are they coming along?

In 2009 'Zilch' on Audiokarma said that they do not need to be replaced.  I have a cheap Capacitance meter but what about ESR?

 

I am still gathering parts.  Have tweeter domes and foam rings, grill emblems in hand, grills on order ad well as new pegs. 

 

Need to go get some black and white paint as the arts supply store, some black satin rustolium and some wood filler. 

 

I have sanding disks, stain (for the wood filler) BLO and mineral spirits on hand (or maybe need some Watco Danish oil).

 

Fun little project.  I like these.  I just restored a pair of L20Ts last year. 

 

32 minutes ago, RandyH000 said:

no -  but the Jantzen Z caps are known to be very good for the JBL L100 , Kenrick Sound in Japan uses these caps for their crossover recaps in JBL Studio Monirors 

I read that today.  My L Pads and crossovers seem to be working fine.  But I can easily order parts on Partsexpress for about $50 and build new ones with the Jantzen caps and new 50w L Pads. 

 

I do want to retain the original sound of these.  Part of their charm. 

 

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Here is the post from 2009 on AK. 

 

What about the ESR.  Do they go out of spec or did they originally have a high ESR built into the speaker so it does not matter if they have drifted? 

 

 

 

Zilch

Zilch Curve Junkie Subscriber

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Those are sand-filled film caps.

Generally, if the seals are intact, they are fine.... :yes:
 
 
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24 minutes ago, tigerwoodKhorns said:

I do want to retain the original sound of these.  Part of their charm. 

 

JBL -HARMAN have a new JBL L100 -my guess is the HARMAN Parts guys have all the answers ---give'em a call

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Here we go:

 

 

The vintage of caps used in the L65 Jubal should not need replacing.

 

Most modern caps have their tin-spray end-terminations fail.

 

Those JBL caps are a stacked-film type and have hand-soldered Teflon leads, are placed in a sand filled tube (for damping), and then filled with wax.

 

The sound better, and last longer than inexpensive polypropylene types.

 

A quality 100V cap should be fine, 100W/8Ω is only 80V P-P.

 

Another quote: 

The paper tube is filled with sand to damp microphonics and then end-filled with wax. The capacitor element is a stacked-film type with hand-soldered teflon leads. The manufacturer was Electrocube, and I would wager they are still good, and may sound better than some of the cheaper polypropylene types.

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1 hour ago, tigerwoodKhorns said:

Another quote: 

The paper tube is filled with sand to damp microphonics and then end-filled with wax. The capacitor element is a stacked-film type with hand-soldered teflon leads. The manufacturer was Electrocube, and I would wager they are still good, and may sound better than some of the cheaper polypropylene types.

I just love marketing audio babble speak. I hope they did not use quartz sand because that is piezo electric generating stuff and might effect the micro and macrophonics.

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I used BLO  on my 4311s  but that was over 15 years ago. They still look good. I'm torn aboult replacing the tweeters...need to check the leads on one. The need new foam rings no matter what.

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7 hours ago, Marvel said:

I used BLO  on my 4311s  but that was over 15 years ago. They still look good. I'm torn aboult replacing the tweeters...need to check the leads on one. The need new foam rings no matter what.

I looked at the rings and moved on, then ebay sent me an offer for $8 delivered. 

 

12 hours ago, Dave A said:

I just love marketing audio babble speak. I hope they did not use quartz sand because that is piezo electric generating stuff and might effect the micro and macrophonics.

I would agree, but JBL never advertised this, or at least never did so in any big way.  They just specked the caps this way from their supplier.  This was 50 years ago. 

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On 4/27/2021 at 12:45 AM, Dave A said:

I just love marketing audio babble speak. I hope they did not use quartz sand because that is piezo electric generating stuff and might effect the micro and macrophonics.

 

Which is exactly how solid state radios work.  A piece of quartz tuned to a certain frequency.

 

They can also be made to glow.  The process is called triboluminescence and it is easy to do at home if you have two pieces of quartz.  Take one in each hand, and practice striking the sides together running the length of the sides.  In a dark room, you will see blue sparks appear inside the quartz.

 

Wintergreen Lifesavers will also do this.

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1 hour ago, Oicu812 said:

 

 

Which is exactly how solid state radios work.  A piece of quartz tuned to a certain frequency.

 

They can also be made to glow.  The process is called triboluminescence and it is easy to do at home if you have two pieces of quartz.  Take one in each hand, and practice striking the sides together running the length of the sides.  In a dark room, you will see blue sparks appear inside the quartz.

 

Wintergreen Lifesavers will also do this.

 

Listen, I don't care what you say, I will not be putting any glowing quartz or Wintergreen Lifesavers in my crossovers. 

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