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Radial vs Axial Capacitor Help


Jhakobe

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8 hours ago, Jhakobe said:

25uf and 20uf, 10% tolerance. 


I probably would have cheated and used a 22uF and a 27uF - both within 10%. 
 

The problem you have there is if you didn’t glue them down, then they are largely only being supported by their leads, and the inside of a loudspeaker is a pretty hostile environment. 
 

I’m surprised you didn’t update the blue mylars while you had them out. 

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7 hours ago, Deang said:


ESR @1kHz is about the same as a Mylar. 
 

 

 

32AD4AEE-EFB1-4009-9A69-0306F1012605.jpeg

It is not the ESR that is the problem using electrolytics in the signal path. As you have found the ESR is very close to the same in both. It is the dielectric absorption of the electrolytic that does not make it a good choice in the signal path. From memory an electrolytic dielectric absorption rate can be as much as 20% whereas a polyester cap is around 1% with an polypropylene even better. The engineers at Klipsch have determined a polyester is plenty good enough. 

 

Dielectric absorption is when you apply a voltage to a capacitor then short it out and the voltage is subject to come back 20% from the original amount in an electrolytic. In other words you will have a yoyo in the signal if you use an electrolytic in the signal path. That and an electrolytic will always have some leakage.  

 

There is a discussion on a technical forum right now with some claiming they can hear differences in resistors in a circuit. I cannot say they do not but like different film caps I am skeptical most can tell any difference. The circuit design in a electronic product is far more important as long as reputable parts are used whether resistors, caps or inductors. I am not one to say what one hears or not hears not having their ears but I am skeptical unless it can be proven on the bench with testing. 

 

Just trust the sound engineers know what they are doing. Klipsch still maintains good quality control from all that I see on the net. Another way to put it is the engineers at Klipsch seem to be able to still keep the bean counters in check and have the last word.

 

Those with some electronic knowledge may want to play with different parts but the majority on this forum should just trust Klipsch and get authorized parts from them. You can be fooled into believing what you are hearing is better very easily when changing parts. Especially when large amounts of money is involved. 

 

Klipsch for caps and Dean for crossover work and you will not go wrong. 

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7 hours ago, Deang said:


I probably would have cheated and used a 22uF and a 27uF - both within 10%. 
 

The problem you have there is if you didn’t glue them down, then they are largely only being supported by their leads, and the inside of a loudspeaker is a pretty hostile environment. 
 

I’m surprised you didn’t update the blue mylars while you had them out. 

Support for their environment is concerning to me as well. Given the space inside the cabinet and on the board, this seemed like my best option, short of running longer extensions to remotely positioned caps. The caps feel secure in their position presently. Do you think I should try another option or give it a go and repair if it fails?

 

I’m not operating under the assumption that Mylar caps are a degrading component in a crossover network unless they show physical signs of damage or cap replacement isn’t successful in restoring sound quality. Flawed thinking?

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2 hours ago, John Warren said:

Much appreciated suggestion. I saw those and considered using…I opted against them due to the 20% tolerance.
 

The original cap tested outside of its 10% tolerance prompting replacement. The 24uf with 20% tolerance puts their range outside of the original spec. That said, if the conventional wisdom here is that this is an acceptable range and I’ve made an error in emphasis on the tolerance spec, I’d certainly consider using the 24uf cap or putting back the original caps (which I think are testing around 12% of their stated value).

Edited by Jhakobe
Typing before sufficient coffee.
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10 hours ago, Deang said:

-2 with 50 mph gusts here in Dayton. Most things are closed with widespread power outages. No mail today and probably won’t get anything tomorrow either. I actually don’t expect anything to show up from USPS until Tuesday, since Monday is a Federal holiday. 


I wondered about how the dual-whammy of weather and the holiday rush might affect your receiving that kit before the weekend... no rush, I've got other projects for next week, including a 15-minute plumbing task that will probably take me 2 hours :-O.

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2 hours ago, Jhakobe said:

Much appreciated suggestion. I saw those and considered using…I opted against them due to the 20% tolerance.

 

What do you think are the typical tolerances for Al-electrolytics?

 

And, I suppose, if you really want something at or very near 25MF you could buy 100 of them and sort.  You should find three or four around 24-26MF.

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32 minutes ago, John Warren said:

 

What do you think are the typical tolerances for Al-electrolytics?

 

And, I suppose, if you really want something at or very near 25MF you could buy 100 of them and sort.  You should find three or four around 24-26MF.

Typical manufacturer claimed tolerances seem to be 20%; +50%, -10% (and similar broad, non-equal ranges); and 10%. 

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15 hours ago, Deang said:


I probably would have cheated and used a 22uF and a 27uF - both within 10%. 
 

The problem you have there is if you didn’t glue them down, then they are largely only being supported by their leads, and the inside of a loudspeaker is a pretty hostile environment. 
 

I’m surprised you didn’t update the blue mylars while you had them out. 

 

I seem to remember someone posting about using permanent glue.  Sounds like a very bad idea.  Isn't hot melt ideal, strong but you can break it loose if need be?

 

I remember installing granite counters in my old house and my friend who owned a granite shop told me to use cheap painter's caulk, not the expensive GE Silicone that I was going to use, because once installed you can never remove the sink without braking the counter.  Same idea here.

 

 

 

 

 

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Thoughts- 

 

As Tecate/GEM are the only approved/ authorized Klipsch capacitor manufacturer/ supplier, would there be sufficient quantities needed to make these caps in form factors that would directly fit the original XO boards? Do Chief Bonehead, Dean, and the powers that be, have any sway here? 

 

I think more restorers would go with the GEM replacements if there were a direct replacement. I thought some caps were getting smaller as manufacturing processes have advanced.

 

Right now it's kind of a mess to get things right.

 

Again, just me thinking out loud...

 

 

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They are what they are. The smaller caps should drop right in. It’s only the spot for the electrolytic that creates an issue. The easy and acceptable fix is just to use what was originally in there - another electrolytic. Thousands upon thousands of vintage loudspeakers used them with no complaint until people’s ears started being tickled with nonsense. The complaint is ironic considering what people are stuffing in there these days. I used to build them a mile high, lol. 
 

I do get what you’re saying, but what I’m beginning to find out is many don’t know how to get their networks out much less know how to work on them. Providing drop in parts won’t help those folks. Some want them worked on, but think Klipsch just wants to lock them into old technology, and prefer faux “upgrades” from another vendor.

 

I’m going to move the resistor to the bottom of the board and use hi temp silicone. This should create plenty of room for the polyester. I may have to use spacers and slightly longer screws. 

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On 12/23/2022 at 5:07 PM, tigerwoodKhorns said:

The electrolytic is parallel to the woofer so not in the signal path. FWIW, Roy had said to use an electrolytic and not go to a film or poly cap as it would not make a difference ( I am assuming the last part).  I just went with electrolytic from Parts Express.

 

Until last evening I didn’t have a diagram. I finally made one (probably should’ve started with this) and you are correct - the caps I’m replacing are both parallel.

 

As mentioned, I would have preferred to use electrolytics and agree they are sufficient for this application, but I couldn’t find the correct values and tolerances. The Dayton polypropylene caps match exact but are comically large.

 

What do you think about values/tolerances being exact when they are wired parallel - is it less important than if they were in series? Is there a capacitance range and tolerance which would be acceptable?

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After rereading many of your comments and reviewing other similar topics here and other places, I’m attempting to parallel two caps to get the required rating.

 

I’ve attached two 10uf to equal the 20uf of the original (in photo). The other required rating is 25uf and I plan to use a 10uf and a 15uf.

 

Any comments, advice, critique appreciated. Thanks again everyone. This has turned into quite the learning experience. 

93608FC0-3873-405E-94A9-67D7EB842E61.jpeg

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