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Type AA crossover rectangular capacitor replacement


Tizman
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The round magnet K-77 can only handle two watts. If newer square magnet types have had their diaphragms changed out with newer ones - then those also only handle two watts. They were typically taken out by the on/off transients of older solid state units - until the zeners went in. 
 

The small coils are probably fine. I’ve never run across one where the wire is loose or separating. The same can’t be said for the autotransformer or low pass coil. Many don’t even pass physical inspection. If the wire bundle has separated from the core, it should be replaced. 
 

These parts are 50 years old and look like salvage from the Titanic. It’s like looking at old tires and using a digital caliper to check the depth of the tread to decide whether or not you need new tires or not. 
 

And Henry, it’s never a bad idea to check your nails and glue, as KLF owners can attest to.

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On 11/26/2021 at 5:39 AM, Tizman said:

Hi All.  I picked up a pair of Klipschorns!  They are bass cabs from the 50s with K-33-E in them, k-400 horns with K-55-V drivers and square magnet K-77 tweeters.  They sound a little off as compared to my La Scalas and sound flat with fuzzy imaging.  I was about to switch out the capacitors, but measured the ones that could be measured in circuit, and they measured reasonably well.  I haven’t seen these caps before in a Klipsch crossover so I was hoping on getting your opinions on switching them and the need for it.  Please have a look at the attached photos.

859536B5-C0F1-4D2D-913A-2663C011D5F5.jpeg

5B60F39E-94B3-4ADF-8C67-A1FE2D9B24B1.jpeg

 

I would replace the crossovers with ALK's crossovers. I recently modified my 87 Khorns and the result was fantastic. I spent about $4500 total, replaced the crossover with Al's extreme slope, Greg's mid horn with BMS drivers. DE2 tweeters with DaveA's lenses. People that visit who are not into audio have said great it sounds.  Comments like it's as if the musicians were in the living room. The speakers sound bigly better than the new AK6's in the dealers listening room

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2 hours ago, Deang said:

They were typically taken out by the on/off transients of older solid state units - until the zeners went in. 

 

Whenever I have seen this the woofer jumps about a mile from the transient "thump", didn't think this would effect the tweeter since the transients measured were low frequency hence the woofer excursion. I suppose it could be more of a "pop" than a thump that would maybe hit the tweeters. Muting circuits are our friends and this is why.

 

2 hours ago, Deang said:

If the wire bundle has separated from the core, it should be replaced. 

 

Are we talking about the bobbin being a little loose with an EI core? If the bobbin is loose it shouldn't be much of an issue, just wedge some popsicle stick or any small wood between the core and bobbin, happens all the time and not a big deal.

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3 hours ago, Deang said:

Most of my customers probably wouldn’t go for the popsicle stick mod. 

 

That was not meant for a tech fix but for an owner that just wants to tighten it up easily.

 

A tech should be able to secure the bobbin to the core more professionally of course. My point being there is no reason to chuck a transformer in the trash because the bobbin is a little loose.

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10 minutes ago, RandyH said:

any suggestions ?  do tell

The first thing that comes to mind is cyanoacrylate (AKA - super glue). It flows well into tight spaces and comes in different viscosity. Buy some from a “model shop” and you should be able to choose thin, medium or thick. Medium would probably work best. 

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33 minutes ago, geoff. said:

these are actual Klipsch parts from an AL crossover, looks like treated wooden wedges to me

20D2047B-6128-4EE4-8238-717AA0F23B0A.jpeg

 

Yes exactly!!!

 

You can pull the wood shim out, clean and re-treat, sometimes still requiring some shimming.

 

But really the easiest thing for any diy person is just shove some popsickle sticks between the wood block and core, the popsickle is a good thickness for a shim to tighten snug things up.

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I especially like the AA types on Brazilian rosewood wood panels. Nowadays under species protection. But I agree that flamed maple also has its charm.
In the end, the regulations for older Klipsch AA xovers were a bit more lenient.

https://www.adkguitar.com/blogs/news/cites-is-being-lifted-what-this-means-for-musicians-manufacturers-and-dealers

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20 hours ago, henry4841 said:

Years ago I experimented with many different capacitors in my crossovers. Just playing around. Different brands do sound different to my ears. We all do not hear the same and we do not have the same listening room. Many buy Crites crossovers and like the sonicaps. Possible have over damped rooms where they may shine. Much the same with different coupling caps in tube amplifiers. Brands do sound different. Probably has to do with the manufacturing process and quality control since they have much the same spec's on paper. At low to mid volumes one will not hear much if any difference between brand of caps. It is when you crank them up you start to hear differences. 

 

The most important thing is IF YOU LIKE THE SOUND YOU NOW HAVE LEAVE THEM ALONE. Why try and fix what is not broken. 

However, this is about different materials and their electrical properties, not about brands. 
But sure, if someone is very happy with what he hears then I can respect it very well. 
My point is that if someone has never heard what might be the best match for the speaker, he should give that combination a chance, whether he is currently happy or not.

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3 hours ago, KT88 said:

However, this is about different materials and their electrical properties, not about brands. 
But sure, if someone is very happy with what he hears then I can respect it very well. 
My point is that if someone has never heard what might be the best match for the speaker, he should give that combination a chance, whether he is currently happy or not.

I really do not think, nor should anyone else, that what separates the plates of a capacitor if it does it's job adequately should make any difference in the sound. Nothing wrong with polyester but not superior to the more modern polypropylene. I am sure if the cost were the same polypropylene would be used. If one believes any differently they are just fooling themselves. It is just simple mechanics and electronics. But social media boards love to debate such a silly thing as the dielectric used to keep plates of a capacitor apart. Foolishness actually. 

 

That being said one is perfectly fine spending their money wisely and buying polyester caps to save money as the engineers at Klipsch have knowing there is no difference in sound. Other manufacturers do the very same thing. That is what engineers do. Find a part that works then try and find a part that does the job just as well saving the company money. They use the specification sheets manufacturers supply to dealers such as Digikey and Mouser for this reason. 

 

CBheart, an engineer, stated the facts about inductors which is true. An iron core inductor is not going to saturate in a crossover network and does the job just as well as the more expensive ones saving the company money. Much the same thought on capacitors.

 

But touting some part better then others is what we do on social media boards to generate conflict and debates with long threads. Gives us something to do.

😃

 

 

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Your point. If you disagree with what I posted it is fine, no problem. One can believe anything they care to. It was just my 2 cents. You would be in good company. There are many that disagree with me about a lot of things. All is good. I am sure if you filled a room with audio engineers there would be heated debates on many subjects. PWK carried a button on his lapel. 

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40 minutes ago, henry4841 said:

An iron core inductor is not going to saturate in a crossover network and does the job just as well as the more expensive ones saving the company money. Much the same thought on capacitors.

 

They purchase parts knowing the specification needed so that the inductor will not saturate under normal use, say up to 100 watts. The iron core vs air core was a no brainer for them really, the price is cheaper and there is less DCR for better damping. If they did get an air core with the same DCR and inductance it would be huge and expensive for no benefit.

 

The problem is someone reads somewhere that air core does not suffer the same core interaction problems and so they are superior. Although this is true, it is much more prudent to just use an iron core inductor where it is sized appropriately to not saturate the core. You end up with the same low distortion signal but with lower DCR and for less money which the savings is passed onto the consumer.

 

It's the same as someone reading that silver has a lower resistance vs copper. Yes this is true but instead of purchasing a silver cable it is much more prudent to just increase the size of the copper conductor and you will lower the resistance much more than just using silver. So a 14awg copper speaker cable, non-engineer says I know more than everyone because silver has less resistance so I am going to use 12awg silver. Besides even the cost of silver going with a 12awg copper will yield a lower resistance than 14awg silver. I know, why not just use 12awg silver cable, here is where price comes in, it is cheaper to just go down to 10awg copper. And don't say you will purchase 10awg silver cables, that is ridiculous but the same argument keeps going in circles, just go to an 8 or even 6awg copper conductor. Jumping up a size in copper is always better than switching conductor material. The layman says silver has lower resistance vs copper so it is better, you can't tell me otherwise. An engineer asks what are we trying to do? Lower resistance. Ok, well we could use silver but that is expensive and doesn't gain us much or we can just jump up a size in copper conductor and lower the resistance. The latter is the better way of doing it of course but don't tell an audiophile that, silver is always best so if you don't use silver you are not hearing your stereo at it's best.

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