Charge Coupling on the Cheap

[Rudy Kleimann]

I believe it's zero-crossing.

So long as the peak-to-peak voltage of the signal is less than 18V, the charge on the "plates" never reverses.

Think of it as Class A operation of capacitors....

I agree, Zilch. Only thing is, where are you getting 18Volts?

[Zilch]

Battery biases at 9V.

Signal is AC.

It'd take an 18V P-P signal to drive the cap tiepoint to 0V.

That's plenty loud for compression drivers....

40.5 peak W across 8 ohms, 20.24 W RMS, no?

[Robh3606]

Hello Ian

I am a bit confused by what you have written in the above post. To quote myself from 133

If you look at the CC schematics for the L250Ti Jubilee, 4344MK2, and 4348 they don't CC the woofer caps. The effect must not be audible in the woofers range at least down around 3-400Hz where those woofers crossover so I would follow the example and not go through the expense for the 4345. If you look at the 9800/9800SE schematic they do CC the woofer caps but the crossover is at 800Hz. I am using CC Solens on my 2435's and it sounds just fine.

This is a far cry from:

The 4344Mkt11 only had the mid, HF and UHF charge-coupled and not bypassed. There is no definite indication of what capacitors varieties where used or why in the above systems. We do know the latest Everest statement appears to use Solens in some areas from visual indications. Often the schematics are simplified so we dont know for certain what's in them. There is absolutely no continuity in any the systems, nor specific details as to what was done and why regards the networks. Obviously certain things were done a certain way for a reason. That's all we know.

There most definately is a pattern here. If you look closely at Don photos you can see that the lowest crossover around 150Hz or so in the Everest 2 is not charge coupled. All of the other crossover points are CC. So below 300Hz as a cutoff JBL does not use it. All on the crossovers that feed the compression drivers/midranges and up have fully CC networks across the board. Check them out in the Consumer Links.

There is no definite indication of what capacitors varieties where used or why in the above systems.

That's not entirely true. In the 4344Mk2, L250Ti Jubilee, 4348 use NPE electrolytics. In the original 9800 schematic we used for May JBL was using CC Mylar bypassed with PP. They then switched to CC Solens in the SE. We don't know what was used in the 9500 but we have a good idea elsewhere.

Often the schematics are simplified so we dont know for certain what's in them.

That's from a PM I sent not the post. It was in reference to the Everest 2 schematic that was posted by Sgt. Shultz . It was a simplified schematic not an actual and it did not show either the CC or Bypass caps that were clearly in the photo's. Most of the posted schematics are complete once you check the capacitor legends. They don't always draw in the bypass caps but they do show up in the legends.


Rob

[Ian Mackenzie]

I have never pulled apart a JBL system ie 4344mk11 or other design in "production" and made my own assessment of what sounds different,improved or otherwise in the crossovers so I would prefer not to speculate.

Do you know the brand and specifics of the Mylars and bypass capacitors and NPE's? Any data sheets on what they used?

Perhaps if someone would like to arrange an evaluation of Mylar capacitors bypassed with PP capacitors used by JBL in a L250Ti and compare them with Solens both with and without Charge-Coupling that would be useful input.

The term simplified schematic I have sighted on numerous JBL crossover files including the 4345 3145 network. Anyone who works or has worked in manufacturing or production knows what actually goes into the product can vary from time to time. Notes are sometimes made on the schematics about changes and updates.

Cost is most likely an issue and one would conclude from your remarks that JBL has adopted the cost leadership approach.

But we can't be certain of that is the only consideration and I would never cast a back and white line on that JBL have done as they are known to be gifted and maticulous with the tuning and voicing of the systems.

Everything is done for a reason and the whole is often more than the sum of the parts.

Back to the point though, if you have no cost limitations and can afford seamingly better at least by your own assessment(as in a diy upgrade) then you have some choices.

Ian

[Robh3606]

I have never pulled apart a JBL system ie 4344mk11 or other design in "production" and made my own assessment of what sounds different,improved or otherwise in the crossovers so I would prefer not to speculate.

Who's speculating?? I never made any remarks about which was better.

Do you know the brand and specifics of the Mylars and bypass capacitors and NPE's? Any data sheets on what they used?

The Mylars used are somewhere buried in the Forum. NPE's???

Perhaps if someone would like to arrange an evaluation of Mylar capacitors bypassed with PP capacitors used by JBL in a L250Ti and compare them with Solens both with and without Charge-Coupling that would be useful input.

The last version of the L250Ti produced used CC NPE with PP bypass so you may want to include that as well. The schematic is readily available on the site.

The term simplified schematic I have sighted on numerous JBL crossover files including the 4345 3145 network. Anyone who works or has worked in manufacturing or production knows what actually goes into the product can vary from time to time.

That's true and we may never know the specific parts used. However you can use parts from 5 different manufacturers and easily meet the schematic. The schematic is not a detailed parts list, just a representation of the parts used and the values/tolerances. When I was talking about a simplified schematic. I was talking about a single cap value shown that was actually 4 caps used to make the required value with the resistors and battery sources not shown for the CC. That's a bit different.

Cost is most likely an issue and one would conclude from your remarks that JBL has adapted the cost leadership approach but we can't be certain of that is the only consideration.

I was trying to give you a actual account of the parts used that I had hard information on. That's all.

But we can't be certain of that is the only consideration and I would never cast a back and white line on that JBL have done as they are known to be gifted and meticulous with the tuning and voicing of the systems.

Everything is done for a reason and the whole is often more than the sum of the parts.

Based on past experience, building clones of several systems and using stock networks I have no doubt the original parts selected by JBL are voiced for use in those systems. I have no reason to believe that has changed with the current systems. Can they be improved upon when cost is not a constraint?? Yes, but I would take Greg's lead from his post and the application of CC networks used by JBL as guidelines as well as the types of caps used where this is available. It's obvious that part selection can effect voicing of the whole system so for those building a clone I would use the exact same capacitor types to hear what the original voicing was and go from there. Any changes may very well be just different and not an actual improvement from the original design. From my own experience I think the CC networks sound better. What are the best CC networks?? Sounds like a driver/system/personal preference call to me. I may like the caps in question you may not. The only way to know is to do it yourself and make your own decisions.

Rob

[Ian Mackenzie]

Practically Speaking

Perhaps manufacturing of NPE has improved over the years.

Quote "I was talking about a single cap value shown that was actually 4 caps used to make the required value with the resistors and battery sources not shown for the CC. That's a bit different. "


I agree it is hard to determine what they use from the schematic. For example the 3145 has 4 x 20uf and 10 uf on the woofer and a 20 uf in the conjurgate. All bypassed with 0.01. The attached image does not really tell much , they say non polarised in the brochure, I can't see the woofer network. Maybe Bo has more pics??

This is what makes it important for the would be upgrader to know what it is they are upgrading and this is what I was trying to say.

For example if the 4345 uses Mylars (?) Bypassed the Solens Charge-Coupled would definately be an improvement. If they used PP bypassed you would have to think a bit harder in terms of different, improved or perfect quality parts (the ultimate).

Draw up a parts list and cost it out per the cost benefit post above. As you say perhaps use NPE on the woofer or it leave it as is (decide if you are biamping?) and focus on the mid, horn and slot filters.

Even buy parts for one channel only for the horn and slot and do your own evaluations and make a call from there.

(*) But as I was saying in the earlier posts, if you have already been up the hill with parts upgrades and other equipment like amps its a whole different ball game to say its time for a upgrade and gee its as simple as A+B+C! You are really saying to yourself here is cool idea but will it do it for me? That is a bit of a ball breaker and I would not be here discussing it if it was that straight forward. I could of course say stuff it and just go out and buy a better loudspeaker system which in reality is another option.

Capacitors are only part of the story.

With something as intricate as this network some members are wondering if they should change out the existing capacitors for better ones or build a whole new network? Putting parts in that will fit will be an issue to be aware of. Do the cost benefit analysis and see if building a whole new network with Solens charge-coupled is more or less expensive than upgrading the current network with good quality parts like Auricaps or Sonicraft Gen11 (just an example).

Quote"Based on past experience, building clones of several systems and using stock networks I have no doubt the original parts selected by JBL are voiced for use in those systems. I have no reason to believe that has changed with the current systems. Can they be improved upon when cost is not a constraint?? Yes, but I would take Greg's lead from his post and the application of CC networks used by JBL as guidelines as well as the types of caps used where this is available. It's obvious that part selection can effect voicing of the whole system so for those building a clone I would use the exact same capacitor types to hear what the original voicing was and go from there. Any changes may very well be just different and not an actual improvement from the original design. From my own experience I think the CC networks sound better. What are the best CC networks?? Sounds like a driver/system/personal preference call to me. I may like the caps in question you may not. The only way to know is to do it yourself and make your own decisions."


You have raised a good point in terms of distinction between cloning or upgrading.

I think we are talking about much the same thing here but as I was saying above (*) this is yet another set of circumstances and its a case of trying it out and seeing of its for you.

Ian

[Ian Mackenzie]

Originally Posted by Ian Mackenzie

This is quite interesting. I have played a variety of CD's Jazz, Pop and so on. My impression is the Solens Charge-Coupled responded well to percussive/string instruments and electronics effects instruments like some of the Larry Carlton stuff I played earlier tonight. The detail and depth of the strings is well revealed with a seemingly polished presence.

Brass is perhaps less well presented and I felt continous notes in complex sections like James Morrison Live in Paris (I asked for the Blues) were less real sounding and at times flat sounding than when played with the Hovlands.Another favourite, Miles Davis Blue in Green sounded flat.

What I think we need to know at this point is are you hearing the intrinsic nature of the Solens or is it the intrinsic nature of the CC ( or both)

for example it maybe the basic nature of the Solens that sounds flat and less real sounding and not the CC itself. the CC might just be smoothing out and cleaning up what is already there ( or not there)

I have run the Solens this afternoon to re confirm the earlier evaluation and after being connected to the battery for few days and I am getting the same result, dry,lacking tonal color, flat and uninteresting. . Dettol or Iodine anyone.

In comparion to the Clarity capacitors that I have just switched over to, there simply is no comparison.

Yes I am shaking my head too, it does make you wonder and I would like to point to a technical explanation. I will refer the charge-coupled topology to Passlabs in the rather unlikely event it is doing something to the amp.However I am more inclined to say its a combination of actually using a hi end amp and some improvements like the acquaplas diaphragms which are vastly more revealing of timbre and tonality. They simply are more natural than the titanium.

We later wound up the system (Clarity capacitors) to about 105-110 db with meter just starting to move.

Playing the recording below my friend Nick Hopkins, a Pom and muso said he had never heard anythng quite like it off a CD, you could hear exacty how they were playing the drums and other stuff. Full marks to the recording engineer. We both thought the amp had a lot to do with it.

I might order some Auricaps or Hovlands during the week and be done with it.,I can then ship the comparison network to who ever wishes to try it..
Ian
http://www.audience-av.com/passive.htm
http://www.hovlandcompany.com/produc.../features.html

Klaus,

I got the CD today Dark Clouds ..a beautiful recording I am playing at the moment.

Thankyou

Ian

[JBLnsince1959]

Ian:

since the Carity caps seem to be soft a little on the top and not as dynamic as the Hovlands...have you considered combining both the carity and hovalnds together to see if you can get the best of both worlds since they seem to voice the same?

[Ian Mackenzie]

No is the short answer.

I think soft is an over statement.

I will audition them during the week and provide more details but I am done here. When I get time I will mail the boards over and you can all draw your own conclusions.

Hearing is believing as they say.

Ian

[Ian Mackenzie]

You can buy Clarity SA capacitors from here:

http://www.diycable.com/main/default...84c1e535634bad

Quote from the above link:

"This is the performance king. The SA series of capacitors will compete with any polypropylene capacitor made. If your thinking of dropping a lot of cash on some expensive boutique capacitors you better sample these first!

These are really great for high voltage tube amp applications in coupling, or bypass positions. These are also ideal for speaker crossovers even though their voltage rating is far in excess of what is needed. The SA Series were developed in consultation with B&W’s engineers for use in their Nautilus Series of speaker crossovers. These are no compromise capacitor design where performance is the number one priority. "

The Solens can be purchased direct from Solen or from one of several suppliers incl Parts Express .

[Ian Mackenzie]

No is the short answer.

I think soft is an over statement.

I will audition them during the week and provide more details but I am done here. When I get time I will mail the boards over and you can all draw your own conclusions.

Hearing is believing as they say.

Ian

I re evaluated the Clarity SA capacitors tonight with a guest (an audiophile)

The comment was they do nothing obviously wrong. Balance from top to bottom and tonality is flawless. Resolving power was impressive and rendering of complexity was natural without any hint of hash (noise) or harshness.

The Clarity SA Capacitors have a slight hint of a warmth and this can be a welcome thing with aluminium and titanium pistonic drivers.

Highly recommended and excellent value for money. There simply is no competition at this price point.

[Ian Mackenzie]

I have posted edited highlights of this thread over on diyaudio.com to gleen responses from speaker builders on the diyaudio forums.

http://www.diyaudio.com/forums/showt...45#post1024545

[Ian Mackenzie]

The Claritcap's certainly pass a lot more information.

There appears to be a lot more ambience and fine details compared to the bypassed polypropolyne metalised caps.

I suppose this is to be expected. I sense that charge coupling cleans - up the hashness of lesser capacitors making them sound smoother, and if bypassed will offer more air and space.

However, a capacitor is what it is and the quality of the film, foil and winding technique will determine the ultimate degree transparency and tonal accuracy.

Jeff said as much in his response to me regards biasing the Sonicaps.

Incidentally Audience advise charge coupling their Auricaps is unnecessary.

I would suggest having previously used both Hovlands and Auricaps that charge coupling of very good to premium capacitors is probably not going to offer any real improvements. On the other charge coupling its a great way to experience smooth clean performance of moderately priced crossover caps.

These are only my observations, but if you are insane enough to spend $2000-3000 charge coupling a complete passive crossover with Holvands you may well be justified with a claim that it makes it sound better on the way to the nut house! (the money would be better spent on a better source or amps)

Ian

Perhaps this post should be a sticky. Common sense prevails in the end. However if you are curious and not a diy atheist its worth a try.

I would like to reconfirm those 4345/4344 people who would like actively participate in evaluations of the Solen Charge Coupled and Clarity Equivalent crossovers. Note these 3145 equivalent crossovers are only suitable for biamping. Please Pm me you name and location.

The product will be shipped from Australia so it will be necessary to work out some logistics. There will also be a shipping cost and this is estimated to be in the order of US$75.00 to the mainland U.S.A. There may also be members in Europe. The crossovers are valued at approximately US$300.00. If you are able to collectively contribute to overseas shipping cost please let me know.

I don't want them returned and ultimately someone can buy them or they can go up on the market place.

Ian

[Ian Mackenzie]

As a result of several requests the crossovers boards will initally make their way over to Europe. Our friends in Europe continue to impress me with their diy endeavours and I am sure they will have a lot of fun with these networks. If anyone is interested in the U.K I am sure they can be slotted in.

The boards will then come back to the States via N.Y. then the Mid West and then over to the West Coast.

The itinerary will probably change a bit here and there as people pop up and express interest.

Ian

[Ian Mackenzie]

Charge-Coupled Interconnects!!

Last night I was trying to figure out a more universal way of verifying and expressing the audio properties of capacitors and I struck on the idea of using an interconnect.

Why an interconnect you ask? Why not! My inclination is this is more critical than crossover applications because we are dealing with low level signals and the full audio band.

So what I have arranged is a set of identical stereo RCA- RCA leads.
At one end I have opened the connector and inserted the capacitor under test into the inner conductor and have a plain lead also for comparsions.

So I simply audition the lead and then try the other lead from the output of the Dac/peamp to the X250.5 power amp which are direct coupled

The leads can be changed out fairly quickly.

I have auditioned the Auricap so far and I think they are very very transparent.


The plan is to make up some other leads including a Solen charge-coupled lead and see how they go and the Clarity SA Capacitor.

I'll let you know what happens.

Ian