Vandersteen 2Ci crossover repair

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Schematic

I plan to remove all the components from the boards. I am going to try using a small circular saw blade on my Dremel and cut on both sides of the leads on the back of the board. I should be able to lift up the piece of foil that is holding the lead to the board.
I am plotting out the schematic and am confused by the fact that the pot that is marked 'Woofer' is not connected into the woofer circuit at all. It is part of the midrange/tweeter circuit. What?
 
There are mid and tweeter L-pads it is that simple.
Nothing to do with the woofer.

From what I remember the boards had a lot of lacquer or silicone
on them don't remember exactly. I would clean them as best as
you can, and desolder the parts that need to come off. You might
need a high power (40W) iron to heat these large connections.
I would only use a dremel tool to
clean up any burned areas if there are any. I would not remove
any inductors, but test them at least for DC resistance to try
and see if any are badly shorted - I doubt it.

Also, test the L-pads since I think these speakers were over driven.
 
Soldering on board

I have attached a photo of the back of the board where all the connections are located. You can see where the leads have been bent over and a copper foil with aluminum backing has been placed over them to make the circuits. Then the whole board has a coating on it, to seal it. Since the aluminum side is up, soldering does not work. It would be easier to just make a new board and wire all the connections. The question is whether to use a blank board and drill the holes or use a pre drilled circuit board and fit the components. In that way, I will have solder pads built in. I feel that, in order to properly test all the components properly, I need to remove them from the board.
Joemusic
 

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That looks like a circuit board to me, tinned copper.
What makes you think it is aluminum. It is very difficult
to solder to aluminum.
I would guess that if "soldering does not work" as you say that it
is because you do not have a large enough iron or there is too much
contamination from whatever was used to seal it.

You might try acetone (nail polish remover) or Goo off and a wire
brush outdoors or in a well ventilated area to remove the sealer.
You really only have to clean the areas where the leads are bent over
and you might want to try a very small wire brush on the dremel tool.

I'd like to see a picture of the other side if you have one.
 
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Foil traces.

This board is made up of layers. You have a bare circuit board that has the holes drilled through it . They, then placed the components on the front side and pushed the leads through to the back where they bent them over and cut them about a 1/8" long. Once all the leads are in the back, they cover certain areas with a foil that is copper on one side and aluminum on the other. These made the circuits. Then they coated the whole thing with a sealer.
I have remove a small piece of the foil by scrapping the coating off and then, using a razor blade, cut a square out of the foil and lifted it off the board. In essence, making a simple circuit board. There are place where they have soldered wires on top the foil; but, I think that they have, in some way, removed the aluminum layer and soldered to the copper.
As for the drivers affected, I have one blown woofer and all the rest test OK.
My plan is to make a PCB that will make the same connections as the foil did.
Joe
 

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Looks like they used too low a wattage on the resistors , no wonder they finally burnt out and YIKES could they have possibly crammed more components CLOSER together? I would make a larger board maybe out of peg board and give myself plenty of room for spacing out things.
 
This board is made up of layers. You have a bare circuit board that has the holes drilled through it . They, then placed the components on the front side and pushed the leads through to the back where they bent them over and cut them about a 1/8" long. Once all the leads are in the back, they cover certain areas with a foil that is copper on one side and aluminum on the other. These made the circuits. Then they coated the whole thing with a sealer.
I have remove a small piece of the foil by scrapping the coating off and then, using a razor blade, cut a square out of the foil and lifted it off the board. In essence, making a simple circuit board. There are place where they have soldered wires on top the foil; but, I think that they have, in some way, removed the aluminum layer and soldered to the copper.
As for the drivers affected, I have one blown woofer and all the rest test OK.
My plan is to make a PCB that will make the same connections as the foil did.
Joe

I don't see anything like what you are describing, on the back of the board.

The leads are clearly bent over on TOP of the metal traces, and were probably all soldered to it. It looks like it is just standard tinned copper.

It looks like a standard PCB fabrication, where the leads were pushed through from the top, bent over against the traces for mechanical strength and for a larger electrical connection area, and soldered to the tinned copper traces. (I don't quite understand why they also put traces on the component side. Are any of the leads soldered on the top side? Are the trace patterns the same everywhere, on the top and the bottom of the board?)

What makes you think they applied some sort of bi-mettalic foil AFTER the leads were pushed through the holes and bent over?? The leads wouldn't even be soldered to the traces, that way! And there is no way they could have used a crimped-on sheet of metal with some sort of adhesive to hold it on, and had good-enough connections.

Maybe you should try desoldering some of the leads, on the back, so you can see that there is a hole in the silver tinned trace, where each lead comes through it.
 
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This board is made up of layers. You have a bare circuit board that has the holes drilled through it . They, then placed the components on the front side and pushed the leads through to the back where they bent them over and cut them about a 1/8" long. Once all the leads are in the back, they cover certain areas with a foil that is copper on one side and aluminum on the other. These made the circuits. Then they coated the whole thing with a sealer.
I have remove a small piece of the foil by scrapping the coating off and then, using a razor blade, cut a square out of the foil and lifted it off the board. In essence, making a simple circuit board. There are place where they have soldered wires on top the foil; but, I think that they have, in some way, removed the aluminum layer and soldered to the copper.
As for the drivers affected, I have one blown woofer and all the rest test OK.
My plan is to make a PCB that will make the same connections as the foil did.
Joe

I don't get it. I've repaired/updated many crossovers.

It seems you're making this WAY too complicated. If they were my speakers, I would simply assume the coils are OK, because they almost never go bad, then lift one end of each of the resistors and measure them to make sure they are OK, and then simply replace the five electrolytic caps, either with new non polarized electrolytics, or film if you want to spend money on something you probably won't be able to hear. Then hit the L pads with with Deoxit, rotate the hell out of them until you get tired of it, then hit them with Fader Lube. Test it simply by hooking up a mid range driver to all three outputs with the crossover connected to an amp playing music or voice and be done with it. Besides waiting for the replacement caps it should take about half an hour. Finding a matching replacement woofer is what you should be spending your time on.
 
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Lead connection.

I will be dissecting the lead to board attachment in the next few days. I have the small circular saw blades for my dremel and will slit the 'foil' on either side of the leads and lift it off. I will photograph it as I go, so that we can actually see what Vandersteen did. I do agree with you that some of the components are too small in capacity. I was thinking of using a large resistor in place of the three smaller ones that burnt out.
Joemusic
 
The front view looks very similar if not exactly like mine.
The single white Wonder cap, and numerous red block caps.
The 1000uFs look to be polarized and I do remember noting a low
voltage rating, 40V there. They are wired back to back I believe
and IIRC were Elnas.

There is a 20 mH transformer looking inductor for the Acoustic Coupler
and there should be a poly fuse or thermal breaker in that path. I
don't like how early it cuts out the Acoustic Coupler.
 
I will be dissecting the lead to board attachment in the next few days. I have the small circular saw blades for my dremel and will slit the 'foil' on either side of the leads and lift it off. I will photograph it as I go, so that we can actually see what Vandersteen did. I do agree with you that some of the components are too small in capacity. I was thinking of using a large resistor in place of the three smaller ones that burnt out.
Joemusic

Before you start SAWING them off, try HEATING them!!!

If you go to Radio Shack and buy one of the red squeeze-bulb solder suckers, you can use a soldering iron to heat the solder and remove it with the solder sucker. Or you could spend a little more and get a desoldering iron, if there's one with enough power.

First, just heat one of the leads and try to bend it up and away from the board with a tiny flat-blade screwdriver, while you're heating it.

You might not even need a solder sucker, if you can straighten them first and then pry them from the other side while heating them.

P.S. You don't always have to remove components, to test them. It depends on the schematic. And for resistors, it is ALWAYS sufficient to disconnect only one end. For electrolytic capacitors, it is usually a good idea to just replace them all, if the unit is 20-30 years old. To replace the caps, you could just cut the leads, right at the cap body, and solder the new capacitor's leads to the old leads. That would be OK for any component that had long-enough leads.

If you start sawing, you WILL destroy the board. In that case, consider making a new one by using your dremel, with a small tip, to remove the copper only from lines that would separate the needed connection areas. It's fine to leave way more copper on the board and have much wider traces than Vandersteen did. Your dremel could also drill the holes, if you could find bits with the right shank size, or buy a small chuck-like attachment. The solid carbide PCB drill bits with the large shanks do fit dremels, as is. But they break extremely easily.
 
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Joe, I would be inclined to avoid the PCB you are using (the old crossover board). It looks to messed up to work with in my opinion. Just find the original values of the components (you have them in front of you it appears), and build a new one with good quality components.
 
Too complex, maybe. But, I was taught that in order to properly test the individual components, you need to remove them from the board. That is just what I am doing. I really do not want to overlook anything and regret it in the future. Besides, they are my speakers.

You only have to remove one lead if that. If for example you remove a resistor and that isolates one lead of several other components, then you dont have to do anything to those components.

I'm going to take a guess here and say that you have so little experience that you do not even realize that what you are looking at is an ordinary tinned circuit board, even when many others here with decades of experience tell you that it is. It is plain to see that the leads were bent over and SOLDERED to the tinned board. All I can say is good luck to you! If I stay involved here some might view my comments as insulting so I'll stop now, lol!

If you get the iron that I suggested, try to move fast, heat, bend the lead back up prying as others have mentioned, and remove the lead. Keep it on too long and the land will pull up from the board.
 
Circuit board

Croseiv- I have already acquired the new circuit boards and laid out the traces. I am going to run the traces directly to the components instead of this mass soldering. My main direction now is to get the components off the old boards so that I can get their sizes. The ones that test and look 'OK' I will use, the rest I will replace as needed.
PB2- thanks for the suggestions. It is not that I am disregarding the suggestions of using the old boards, I just think that the boards can be improved. I have already taken care of replacing the damaged Woofer.
When I talked to Richard Vandersteen, he told me that one thing that they were finding when they first marketed the 2Ci speakers /crossovers, was that people played the speakers too loud and would burn out the components.
Joemusic
 
OK then.

I think that you will want to use resistors that are rated for much more power than you expect to be needed.

The reason for that is that resistor heating and cooling actually makes them non-linear, since their resistance changes depending on the signal level, which will cause distortion.

Smaller resistors can heat and cool much faster than large ones, assuming the same current through both. To some degree, the resistance can even change at audio frequencies; moreso at lower frequencies, no doubt. Using resistors that are physically larger will tend to alleviate such effects.

Commonly-used types of fuses also exhibit the same effect, and can introduce measurable distortion.
 
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Croseiv- I have already acquired the new circuit boards and laid out the traces. I am going to run the traces directly to the components instead of this mass soldering. My main direction now is to get the components off the old boards so that I can get their sizes. The ones that test and look 'OK' I will use, the rest I will replace as needed.
PB2- thanks for the suggestions. It is not that I am disregarding the suggestions of using the old boards, I just think that the boards can be improved. I have already taken care of replacing the damaged Woofer.
When I talked to Richard Vandersteen, he told me that one thing that they were finding when they first marketed the 2Ci speakers /crossovers, was that people played the speakers too loud and would burn out the components.
Joemusic

"Run the traces directly to the components instead of this mass soldering"?

What does that mean? The traces HAVE to run to the components. And they already seem to do so pretty-much directly, i.e. without a lot of meandering.

The tinning of the copper PCB traces is usually done in order to prevent oxidation of the copper, as far as I know. And it was usually done before the components were inserted, on those types of boards. They probably soldered each lead individually.

I used to use a product called TINNIT, for that, which required no soldering; just mix the powders with water, at a certain temperature, and then dip the boards for a specified time. Then insert components and solder each lead. You could also use some sort of chemical sealant or conformal coating, to accomplish the same thing. But that would probably have to be done after everything was soldered into place.

It's possible that they used "wave soldering", to solder the components all at once, and tin the traces at the same time. But I kind of doubt it, especially on the component side. Most likely, the traces were already tinned and they just inserted each component and soldered each lead, individually.

If you are making the boards yourself, be aware of the fact that the original boards probably had plated-through holes, which automatically connect the traces on the top and bottom sides, through each hole, so that only one side of each hole would need to be soldered. You most-likely won't have plated-through holes, if you fabricate the PCBs yourself. So you might end up having to drill some "via" holes, and insert short pieces of wire in them and solder those on both sides. If that is necessary, it will probably affect the layout of the traces. It's usually only necessary for components that sit over their holes, making it impossible to solder them on the component side of the board (e.g. certain sockets, radial electrolytic caps, et al), and then only if they must connect to the top trace.
 
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