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Epic CF-4 crossover issue.....missing a cap, and can't read rating of other speaker's cap!


G87

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I recently picked up a pair of Epic CF-4's and WOW. Really, really good. Favorite speakers yet....and I've had a lot of speakers.

 

But things got interesting today.

 

I put each speaker on its back so I could open them up and do some inspecting, and prepare to do some of the minor mods/upgrades I've seen, as well as see what crossover parts I need to order for a refresh.

 

I removed the bottom woofer of the first speaker, and was then staring into the hole at a loose capacitor sitting in the bottom of the cabinet. 2 capacitors actually, wired in parallel - a 33uf and a 14uf, to make 47uf.

 

I take a look at the crossover, and this is what I see:

20190531_181200.thumb.jpg.425faac507018fff4f978499beeb243c.jpg

 

So, that's the woofer section right there which uses the kind of caps that have both leads on one end, hence the two holes together in the circuit board. These loose caps are certainly not from the factory. It's a 'SUWA' 33uf and an ERSE 14uf, with leads coming out each end. To confirm that these aren't stock, I looked in the other speaker and saw this:

 

20190531_181503.thumb.jpg.8bb85f5828587d02ed17902ae1e0f79f.jpg

20190531_181515.thumb.jpg.82e899c54efb18fb8ed714746e839355.jpg

 

That's about what I expected to see. So, the purple cap in the first speaker was replaced for some reason......and somehow the replacements fell off?? Wondering if they were even properly soldered in or if the leads were just stuck down into the holes. I took the top circuit board off to see underneath, if these were actually soldered in, they somehow got so hot that the leads cleanly came off. Is that even possible? There are no obvious signs that they were even soldered in. I dunno. Could be wrong.

 

 

In the end, all that really matters is that I can get the proper value cap to bring it back to factory spec - but if you notice in that second picture of the second (intact) speaker, the original purple cap's jacket is all torn up and the rating is not visible anywhere on what's left of the jacket/coating!

 

I haven't been able to find a schematic anywhere.

 

These are version 3's......does anyone know what uf rating that purple cap is??

 

Or does anyone have V3's that can open them up and see for me? I would appreciate it so much......

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Also - it might make sense to assume that the purple cap is 47uf since that's what the two 'replacements' make together, but that's what the orange one next to it is, and I've been able to find crossover pics of V2 CF-4's as well as CF-3's, and the two caps in those positions are different in every case.....so I'm reluctant to assume that they are actually both 47uf in these.

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8 minutes ago, Blvdre said:

In this post, the electrolytics in the v.1 CF4 crossover are listed as 40uF & 57uF.

 

Hey Blvdre, thanks but I had found that post and since they are V1, they are different. The orange cap in both of my speakers, which is in the position of he 40uf caps in the ones you linked to, is 47uf.....so definitely a different setup. I want to stick with what's original since the V3 have different woofers than the V1 and V2.

 

4 minutes ago, avguytx said:

Maybe they were running out of parts at the end of their life and used what was in the barn to finish them off. 

 

Totally possible! Just wish I knew for sure....

Edited by G87
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I figured as much. Do you have a DMM? You could always pull the cap and measure it. I doubt those caps were ever properly soldered. If they became hot enough to cause the joints to fail, the cans would be bulging.

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5 hours ago, Blvdre said:

I figured as much. Do you have a DMM? You could always pull the cap and measure it. I doubt those caps were ever properly soldered. If they became hot enough to cause the joints to fail, the cans would be bulging.

I do have a DMM - I didn't know you could measure capacitance with one! I'll have to look in to that, thanks!

Also, the smaller Erse cap isn't bulging but it's coating DOES look like it has melted and expanded, like bubbled up and then deflated, leaving it all deformed and wrinkled. So, maybe a good possibility that it did get hot enough somehow. 

 

4 hours ago, glens said:

Like the "original" cap with the split jacket in the other speaker?

 

Might get lucky on that one and find a printed value underneath.  The cap has to get replaced anyway.  

Yeah I thought about that last night! Thinking I'll disassemble and check it out. Maybe tonight.

 

Thanks y'all.

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3 hours ago, wvu80 said:

I think is is CF-4 v3 because in the Notes section it specifies the wire color woofers as red/black.  The v3 is the only one that had red/black wires on the XO.

 

Klipsch CF-4 Schematic(1)(1).pdf 273.79 kB · 4 downloads

 

Whoa! An actual schematic! I looked all over the net for that last night. Your reasoning makes sense - from what I've read, V2 should have the clear wiring.

 

But if Jirachi can get us a pic, we can have absolute confirmation!

 

2 hours ago, Jirachi said:

I can try and take some pics of my v1 and v3 if you guys want comparisons. I have both

 

That would be wonderful!! On your V3's, if you can see a value on the cap in question (position C1 on the board) that would tell us for sure whether the schematic wvu80 shared is correct for my speakers.

 

2 hours ago, Deang said:

Well, since he has V3 ...

 

I think we can safely assume that the value in question is a 33uF.  

 

Hi Deang, I know from my reading that you're no stranger to crossovers - pleasure to have you here. I'm not understanding though - where are you getting the 33uF from?

Edited by G87
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The 47uF stated in the schematic @wvu80 shared would make sense, because that's the value of the detached cap combo is. (33 + 14)

 

Just didn't want to trust that initially since it didn't look factory...

 

But if we can get a confirmation, I'll be putting an order in tonight!

 

So excited :)

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10 minutes ago, G87 said:

But if we can get a confirmation, I'll be putting an order in tonight!

Are you getting a replacement for the damaged caps only, or both of them (side-by-side) for both XO's?  What brand?

 

Sorry that I can't help you with any of that, XO component replacement is above my pay grade.  B)

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51 minutes ago, wvu80 said:

Are you getting a replacement for the damaged caps only, or both of them (side-by-side) for both XO's?  What brand?

 

Sorry that I can't help you with any of that, XO component replacement is above my pay grade.  B)

 

Ha np, I've done crossover work before so as long as I get the values right I'm good to go. :)

 

I'll be replacing all the caps and possibly the resistors with Mills resistors, per @Deang's recommendation in another CF thread.

 

I'll probably use Dayton Precision series poly metalized caps for the caps that are in-series in the HF network, and Dayton regular poly metalized caps for the caps that are not in-series in the HF network.

I'm thinking I'll use Parts Express electrolytics for the LF network.

 

3 hours ago, Deang said:

Sorry! I misread the first post. Yes, 47uF makes the most sense at this point. 

 

Ah ok! No problem.

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Sorry for the delay. Can't get my hand up the ports to get a good picture. Feels like a piece of foam or something was blocking them off. And honestly didn't want to unscrew them because I've done it more than enough times already. Glad you guys got it figured out

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@Deang I'm tagging you here because I know you're a crossover expert, but anyone else with input feel free to chime in!

 

I ordered caps last night, but then realized that the ONLY 47uF electrolytics PE has are +/- 10% and only 100V. The stock caps are 5% and 150V, and I'm having trouble finding lower-priced caps that match.

 

What if I combine 2 or 3 smaller caps with 50-75V ratings - would the V rating stack to 150+?

 

I haven't covered every single base yet, but most - I'll keep looking in the meantime.

Edited by G87
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