Crossover A Klipschorn cap replacement help

[Deang]

I'm still tempted to use a fuse like the AK-3, but will need approval. Just haven't had time to deal with it. The day job has me pretty tied up right now.

 

I've always believed that if a person is determined to blow up their loudspeakers, they will find a way.

 

 

[billybob]

... ☕

[Aoran994]

46 minutes ago, OO1 said:

get in touch with  JEM via email , they are authorized to sell   klipsch Genuine capacitors , tell Jim that  you are in Italy ,   find out how much it would cost to ship 1 kit of A  or AA Network  capacitors  via USPS  or by  mail  , if that does not work , reach out to me by PM   .

 

 

https://jemperformanceaudio.com/    

412-401-6915. theaudioroom@verizon.net                

 

I sent an email thank you 

[Aoran994]

33 minutes ago, captainbeefheart said:

I know first hand the bean counters ultimately call the shots in the end and these would never be considered by any corporation interested in profits but I would love to try these out.

 

Mouser says paper but the datasheet says 2uF 1kv "A" case is a hybrid paper/film and foil capacitor. Most likely paper and polyester. These would be extremely similar to the original can style capacitors Klipsch used. Since the price is not so attractive to me I'll probably stick with the hermetically sealed Russian paper in oil types that I know work fantastic in an AA network.

 

https://www.mouser.com/ProductDetail/Cornell-Dubilier-CDE/SCRN234R-F?qs=9I6i58cghus89mz%2F6eojrA%3D%3D

 

https://www.mouser.com/datasheet/2/88/CDUB_S_A0010162436_1-2540126.pdf

 

 

As for the OP, I'm glad to hear he reached out to JEM for the Tecate caps, they would certainly be the safest choice if shipping/customs costs are not prohibitive. If you live in Europe there is a Bulgarian seller of Russian PIO capacitors, I'm in the states and have purchased caps from them many times with excellent results. If you find that you can't go the JEM capacitor route I highly recommend Russian PIO caps from that Bulgaria dealer.

we will see what JEM says 😁 then if not i could go this route

[tigerwoodKhorns]

8 hours ago, Aoran994 said:

i still dont know what to buy ahahah, too much technical information here, but i am happy that the thread evolved in this,anyway i don't believe in expensive capacitators, i looked out the dayon's but if somebody could help me find something more appropriate here in the EU i appreciate the help

 

15 hours ago, captainbeefheart said:

 

Dielectric non-linearity causes distortion. Hysteresis causes distortion in some caps. Aluminum Electrolytic and Ceramic are some of the most non-linear types of capacitors.

 

When testing capacitor distortion I had to use quite a bit of signal across the capacitor. In a crossover we want frequencies of interest to the driver to pass through unimpeded while frequencies we don't want we impede and shunt away back to the source. What this means is the frequencies that may show distortion are the ones that we attenuate away anyway. The frequencies we want to reach the driver will not create enough of a potential across the capacitor and so no distortion.

 

This is 600Hz at 70v across the capacitors

 

You can see the hysteresis with the Aluminum Electrolytic and Tantalum.

 

 

 

 

Captain already said it, look at the graphs above.  There is a seller of Russian PIOs near you.  That would be my first choice in EU.

[Travis In Austin]

9 hours ago, KT88 said:

his son were also in our Jubilee class. And then back home I had seen what he was doing in business, we talked about it briefly in Hope too in a break from Roy's seminar. So I thought I couldn't get much closer to the original. 
But after I got the xovers from Bob and installed them, somehow the Lascala wasn't as much fun as I remembered with the original caps

Remember you well, you are a good egg.

 

Prost

[Aoran994]

37 minutes ago, tigerwoodKhorns said:

 

 

Captain already said it, look at the graphs above.  There is a seller of Russian PIOs near you.  That would be my first choice in EU.

will wait the price from jem audio, then if its not possible i will try this russian seller

[Deang]

Nope, but I've played with DC biasing (charge coupled network).

[tigerwoodKhorns]

1 hour ago, captainbeefheart said:

 

 

I'd be curious to know if anyone has tried them. @Deang?  You ever try them?

Greg Timbers was skeptical at first and now advocates for Charged coupled.  A member at the Lansing Heritage forum said his Everest were sounding 'grainy' and after a while he realized he needed to check the battery and that cleared them up. 

 

Greg said to just make sure to use film caps and Solens are what everyone was using about ten years ago.

 

I have a pair of 250 TIs that I am considering going charged coupled per Greg Timbers comments, but with that network the cost of the caps really add up. 

 

He is the designer so I will most likely just trust him and go that route. 

[Deang]

I never could decide if it made sense on a film capacitor, especially a film and foil. ALK and John Warren both told me it only made sense on electrolytics. Wow, I just realized something - I think that may have been the only thing they ever agreed on.

 

Does live music sound a little grainy, or is it smooth like butter. Just something to think about.

[captainbeefheart]

14 minutes ago, Deang said:

I never could decide if it made sense on a film capacitor, especially a film and foil. ALK and John Warren both told me it only made sense on electrolytics. Wow, I just realized something - I think that may have been the only thing they ever agreed on.

 

I have never measured a single improvement from DC biasing bipolar film or paper types. The times I have asked people how this improves a bipolar cap I wasn't completely satisfied with their answer which was along the lines of "removing crossover distortion at the zero crossing".

 

With a polarized capacitor the anode forms the dielectric oxide layer when charged so I can see how keeping the anode oxide layer formed all the time via a DC bias will help. If you have ever discharged an electrolytic and removed the short/load you will see a charge form up from the dielectric absorption. Also in testing you can see it reduces hysteresis so it's definitely helping matters. One thing is doesn't change the non-linearity but in a coupling capacitor situation distortion is no different than a film anyway so that's moot. Coupling stages usually block DC so the bias is already there. Many SS amps will have tons of lytic caps in the signal path and you don't hear people complain about the sound, it's way over exaggerated that polarized lytics are going to poison the signal.

 

I can only say I have seen a DC bias improve polarized electrolytics. Really I think the issue is using the two polarized caps back to back to create a bipolar cap works but there must be a mechanism with this arrangement that just doesn't perform well enough for serious audio uses. I feel there is no point for me to spend a lot of time on investigating what's going on at a deep level here since I wouldn't ever use polarized back to back anyway in a crossover and if I had to use a very large value of capacitance  because of a low impedance load in an amp there is often a DC element there to bias the polarized coupling capacitor anyway.

 

Until I see a good explanation and some actual data showing DC bias helps bipolar film caps I'm not on board with that idea.

[tigerwoodKhorns]

1 hour ago, Deang said:

I never could decide if it made sense on a film capacitor, especially a film and foil. ALK and John Warren both told me it only made sense on electrolytics. Wow, I just realized something - I think that may have been the only thing they ever agreed on.

 

Does live music sound a little grainy, or is it smooth like butter. Just something to think about.

I struggle with this.  If charge coupling improves a cap's performance, say of a Solen or Dayton, because there is so much more capacitance used, are you better off with just using higher quality caps? 

 

The interesting thing is that Timbers seemed to think that it was an improvement after he was at JBL just in comments in a forum. 

[tigerwoodKhorns]

45 minutes ago, captainbeefheart said:

 

Until I see a good explanation and some actual data showing DC bias helps bipolar film caps I'm not on board with that idea.

 

 

I can only say that Greg Timbers was very skeptical at first and then later subscribed to doing this.  Likely after testing and listening.  I need typo dig up his posts.

 

[captainbeefheart]

24 minutes ago, tigerwoodKhorns said:

 

 

I can only say that Greg Timbers was very skeptical at first and then later subscribed to doing this.  Likely after testing and listening.  I need typo dig up his posts.

 

 

I found these.

 

I haven't read through it yet but I will and report back.

 

[captainbeefheart]

LOL I just read all that and it's exactly as I presumed, it's to remove hysteresis caused from the dielectric absorption.

 

As most techs have noticed after you short an aluminum electrolytic capacitor to discharge it and then remove the short voltage builds back up.

 

Just like dissipation factor, dielectric absorption is given in a %. The lower the % obviously the less DA the dielectric exhibits. With a film capacitor the DA is around .02%, actually polystyrene caps are a magnitude lower at .002%

 

 

Aluminum Electrolytic caps will have a DA of 10% which is why you should bias them. With a film cap the DA is just so small it's not going to be audible but in theory it is present and measurable. JBL used this trick to allow using cheap Aluminum electrolytic caps in their networks and the bias lowers the hysteresis distortion down to acceptable levels.

 

For 20v the DA would be;

 

20 * .0002 = 4mV    film

 

20 * .1 = 2v     aluminum electrolytic

[Marvel]

I had a former member send me some supposed battery biased crossovers, some A or AAs. His schematic was really not a correct way to bias the caps. @Deang Dean would remember them. I know that I wouldn't want them in my luggage going through an airport. They were scary looking and I finally stripped everything off of them without ever trying them..

[Deang]

Speakerfritz. 

[tigerwoodKhorns]

I found this on Audioheritage, the caps used in the S5500, it looks like they used a mix of film and electrolytics:

 

'I really don't think JBL selected the capacitors based on anything other than cost saving. They are budget bennic style film caps and the larger values electrolytics are ALCAPS found in every budget speaker of the time. Nothing high end here. Just working to a budget keeping the bean counters happy. Giskard recreated numerous JBL networks and never mentioned the importance of keeping the original capacitors, from reading his posts he used anything from Solens to Jantzens. As long as you match the values closely I think using a higher quality capacitors isn't going to harm a thing.'

 

 

 

I also found GT's posts in my server:

 

Here is his post from 2008 :

 

12-02-2008, 05:25 PM #3

gtimbers

 

Member

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I was asked to make a brief response to this last post, so here it is. The capacitor biasing is something that has existed for many years. Tube equipment does it automatically since there is usually a large DC offset between stages. Some early transistor amps/preamps had two polarized caps in series with the center point going to ground through a large resistor.

I personally became aware of this technique for speaker systems through communications with Ed Meitner, currently of EMM Labs. He is a wealth of information regarding these "tricks" to help linearize or improve the sound of passive components.

It turns out that the bias trick actually increases measured IM distortion and the higher the bias voltage, the greater the increase. It is not by a great amount, but it is measureable. The sound imporvement (or change) is very rarely perceived as worse and is never linked with a increase in IM distortion. The sonic effect is one of smoothness, increased spaciallity, detail and stuff like that. IM has a muddling or confusing effect so I doubt that this particular steady state measurement is explaining the sound difference either way.

Simply put, we are striving to create a class A situation but as was just pointed out, depending on the bias voltage with respect to the voltage across the capacitor, we may only have an "A" condition up to a particular drive level. So if it makes you happier, consider the change to be class AB, but heavily biased to A. You must also keep in mind that the voltage across the input terminals of the crossover network does not tell you what voltage or current is applied to any individual component. Some parts block signal and others shunt signal so the loading on a particular part is not obvious. For the most part, the caps are well taken care of with 9 volts, even at healthy drive levels. The obvious choice for 9 volts is the small cheap battery and holders that are available. No current is involved so a smoke detector battery and holder is a natural choice.

We did do one system with 18 v (M9500). Certain of the Japanese reviewers thought it was an improvement. I can't personally tell any difference. I am also told on a regualr basis (again by our Asian customers) that the battery must be changed at least every 90 days and that the sound degrades after that. Once again, I have not been able to "hear" any difference after 90 days and the battery is certainly still good for many years from a voltage standpoint.

What playing around I have done with initial application of a battery to a biased circuit (that has not been previously powered up) is that it takes about 3-5 seconds for the soundstage to change. I have tried to measure the voltage level in that time period and it seems that several volts is all that is necessary to accomplish 90% or more of the improvement. Once a circuit has been energized, it is nearly impossible to return it to zero. You have to individually short out each cap and leave them shorted for a while or else they will creep back up somewhat. If you replace the battery with a short and play the system for a while, the caps will start to bias themselves, although not to anywhere near the same degree.

You can take this opinion for what it has cost you. I have been very pleased with biasing for many years. I use it in all applications that involve a capacitor and I have rarely been disappointed. Results may vary so if it doesn't do it for you that is okay too. It cost a bloody fortune to implement as it requires 4 times the capacitance and double the capacitor parts count. The network size gets huge as well. In spite of this, I have never heard a capacitor type that didn't improve (or change) including the nearly perfect teflon variety.

***  **

 

Here is his post from 2006  where he had done the mod to his own 250s and really liked it.  He is responding regarding a studio 4 way but discusses the 250TI

 

05-02-2006, 04:56 PM #27

gtimbers

 

Member

Join Date

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Los Angeles

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You Guys are Amazing

I can't belive all the interest in this 30 year old system. It was never very successful during its life time primarily due to its size. Most people would get something smaller. It also had a reputation for less than detailed bass, which I have always thought was due to the enclosure not being quite large enough. I haven't thought about these things in years but since I have received a few requests for comments - here goes.

The system was and probably still is a stellar performer if you like the inherent sound of the traditional big JBL 4-ways. There is good news and bad news in the basic design. Good in that they are dynamic as hell and never get confused with intermodulation products of any type. They don't take much power to run and can swallow up a really big amp should you wish to do so. The weak areas of that type of design are several. First, there is a large time off-set between the 10" driver and the HL92 horn. This shows up in both the on-axis response, the directivity pattern and the homogeneity of the driver blending. The second problem is the use of a passive crossover between the top of the woofer and the bottom of the 10". Passive crossovers set to frequencies below about 500 Hz react badly with the motional impedance of the woofer/box combination and give substantial gain around 100 Hz. Gain out of a passive system is generally a bad thing. In the case of the High Pass, we have to work the passive network through a really large motional impedance peak resulting from the 10" fundamental resonance in the sub enclosure. This means that the actual voltage drive that occurs at the terminals of the 10" is less than ideal. There was the added complexity that the Marketing folks of that time required switchable bi-amp capabilities in which the incorrect setting of the switch was not allowed to hurt anything. These little things all add up to additional insertion loss for the woofer and loss of damping control. Now all of this sounds pertty bleak, but as you have no doubt noticed, no one told the 4345 that it can't work correctly so it does anyway.

My sonic memory of the big 4 ways, the last of which was the 4344MkII, is that they are effortless, dynamic, pretty low in coloration and really "alive". They are a little vague by today's standards in terms of precise imaging and although they are very low in intermodulation effects, they are not as detailed as really good lesser way designs. There is no simple answer to any of this and no one design statement that is best. Everything is a series of compromises, and the 4345 has a very good set of complimentary compromises.

I noticed a comment earlier in this string regarding the 2122H. It is a really good voice transducer. It always has been and always will be. Things just sound really natural through it. Another one that might be slightly better is the 2123. It is a little less smooth but perhaps a little more realistic on voice. Either are really good for that critical range from a few hundred Hz to about 1500 Hz.

I imagine you guys have talked about and tried lots of things to get the most out of the system. I will mention a few things that I would do if I had a pair at home for my primary system.

• Get rid of the bi-amp switch. Hardwire it in which ever mode you want it. The switch is not that great.
• If you can work out bi-amping do so. The difference in the 2245H and 2122H will be amazing. The crossover will have to be non standard. Neither driver is flat around crossover so the voltage drives will need to be adjusted to get proper acoustic bandpasses.
• The network components should be updated and this isn't easy. All the capacitors should be polypropylene and you would want to use air core inductors where ever possible. I believe the 4345 used some tapped iron cores. Those are hard to replace with aircores because the surrounding network topology would have to change and all of the values have to be re-engineered. I would suggest leaving them alone unless you are really good at this stuff.
• If you can swing it, go to a biased network. The difference is unbelievable.
• The ring radiator hates passive networks. A major improvement in the upper range would be to drive the 2405 from its own little amp. You only need 3 or 4 v rms. The 2405 does 110 dB for 2.83v. It is padded way down in the system. There is little real power at those frequencies anyway. You only need to know the voltage output of the amp, power is irrelevant. The 2405 is about 12 ohms and won't draw much current. I would use some little chip amp with a 2ond or 3rd order low level highpass in front of it. Take off the passive network to the ring and just feed it straight. Make sure the amp doesn't make a DC thump on turn on or turn off. That will fatigue the diaphragm. The amp will also have to have really low noise characteristics as any hiss will be really loud directly into the ring. I used to use an old Marantz 1030 integrated amp to run my rings. I could separate out the power amp section and the tweeters always sounded really good.
• The L-pads aren't so hot either, particularly after all of these years. Once you have your preferred balance, it is fairly easy to measure each leg of the L-pad and replace it with fixed resistors.
• I notice from many of the pictures that the system is elevated on blocks. It is very good to get the 2245 up off of the floor to minimize midbass fatness.

For resale reasons, you should be very careful about doing as much of this as possible reversibly.

Before closing I should comment briefly about the 250 - 4345 comparison. Simply put, I prefer a 250. I like the bass quality of the LE14 woofer. Alway have and always will. The 2245 when used as a dedicated sub is one of the best sounding woofers ever. It has an amazing blend of speed, pitch and punch. So does the 14" but the 18" is better. Unfortunately the 18" dislike for passive networks hurts it more than the 14" is hurt by a passive network. I think the mid and high range on the 250 is smoother and much more open however the 4345 wins by a bunch in terms of effortless dynamic sound. I have made all of the above changes to 250 systems (except for separate amp on UHF) and the improvement is huge. I have not done so on the 4345 but I suspect that that system will benefit from theses changes more than a 250 would. If both systems were tweaked out to about the same level, I suspect it would be very hard to come up with a clear overall winner, but I think I might lean towards the 4345 as having the greater potential.

Thank you all for the interest in my work. I must admit I have been blessed with a really nice profession that has treated me well for a very long time. Remember that sound and music enjoyment are very personal things and that what makes you happy may or may not please others. Screw them. If you are happy and no one is geting hurt then go for it. No loudspeaker system even approaches real life so there is plenty of room for interpretation.

 

 

 

 

 

 

[henry4841]

8 hours ago, tigerwoodKhorns said:

I found this on Audioheritage, the caps used in the S5500, it looks like they used a mix of film and electrolytics:

 

'I really don't think JBL selected the capacitors based on anything other than cost saving. They are budget bennic style film caps and the larger values electrolytics are ALCAPS found in every budget speaker of the time. Nothing high end here. Just working to a budget keeping the bean counters happy. Giskard recreated numerous JBL networks and never mentioned the importance of keeping the original capacitors, from reading his posts he used anything from Solens to Jantzens. As long as you match the values closely I think using a higher quality capacitors isn't going to harm a thing.'

 

The thing is though if what was used did the job adequately why spend more? JBL like Klipsch was, is, a reputable speaker manufacturer and they had, have, a loyal following for a reason. The engineers know what they are doing when designing, selecting parts for their speakers. Engineers do not select parts by a name but by statistics in the data sheets. If they do the job requested of them I see no reason to spend more money. As stated previously technicians repairing audio gear use a film cap from a reliable source they have in stock when they have a need to replace one. Which is very, very rare for a film cap even 50 years old. Electrolytics are the one that deteriorate with time. 

 

Most should just stick with what works best for Klipsch speakers. Authorized parts and be satisfied you are hearing excellent sound with parts picked by an engineer and not some Joe Blow on the internet. 

[Marvel]

13 hours ago, tigerwoodKhorns said:

Greg Timbers--

Remember that sound and music enjoyment are very personal things and that what makes you happy may or may not please others. Screw them. If you are happy and no one is getting hurt then go for it. No loudspeaker system even approaches real life so there is plenty of room for interpretation.

I love that!