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[FIXED] Cornwall 1 bad crossover help


gsgleason
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1 minute ago, gsgleason said:

 

Yes indeed.  I'm now researching capacitors that won't break the bank.

 

Jantzen, for example, doesn't make a 2 uf. They have 1.8 and 2.2.  Which should be considered?

 

If you have to choose use 2.2uF.

 

IF you want to retain the same type of sonics as the original type capacitors then get some PIO capacitors.

 

These are very good if you ask me and they are not very expensive either.

 

https://www.ebay.com/itm/353676391302?hash=item5258c17386:g:6psAAOSwajVURk76

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59 minutes ago, gsgleason said:

 

Yes indeed.  I'm now researching capacitors that won't break the bank.

 

Jantzen, for example, doesn't make a 2 uf. They have 1.8 and 2.2.  Which should be considered?

You will have to do the changes in both crossovers , since the capacitors are pretty worn out in 1 speaker , they will eventually fail in the 2 nd speaker-

 

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As CBH says, PIO types should be fine. A little faster to get them and to make a test I would take Polyester types like Klipsch does it still today.

My 2 cent: Today's capacitors that are closest to the original ones are polyester types, also called Mylar, as they are also used in the new Cornwall4. These yellow inexpensive types. They make sure that the overall impedance of your xover is not changed. And that is more important than a somehow promised dream sound of an exotic or esoteric or too modern (with too high Q) caps. It has to be the right cap for the circuit, not "the best" in isolation. I had made a logical mistake when I bought mine because I bought a tight tolerance. 
They are so cheap at Mouser that if I were you I would buy the 2.2 mF from a good brand like the Nichicon in my photo (at the bottom). But I would buy 20% tolerance, the quality stays the same good, then three times as much caps as you need and just measure through which ones are closest to 2mF.
The original ones had 20% deviation too, so you're perfectly in the target if you fish out 2.1mF for example.

 

22129951-8677-4CB6-ADA4-37223C717C0F.jpeg

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1 hour ago, captainbeefheart said:

 

If you have to choose use 2.2uF.

 

IF you want to retain the same type of sonics as the original type capacitors then get some PIO capacitors.

 

These are very good if you ask me and they are not very expensive either.

 

https://www.ebay.com/itm/353676391302?hash=item5258c17386:g:6psAAOSwajVURk76


Well, those old motor runs were polyester, but they were film and foil. No PIO cap in a Klipsch speaker since the 60’s.
 

I second this recommendation. metallized Polyesters may be “right”, but they sound hard and gritty to me. 

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23 minutes ago, Crankysoldermeister said:


Well, those old motor runs were polyester, but they were film and foil. No PIO cap in a Klipsch speaker since the 60’s.
 

I second this recommendation. metallized Polyesters may be “right”, but they sound hard and gritty to me. 

I don't want to start an argument about that. It is a subjective thing. But I am very open to try PIO once. Maybe I like them better than the polyester types.
 I'm not fixated on the polyester types. Except that they belong to the group of electrically "correct" ones.
Compared to Sonicaps, I experience the polyesters as warmer and more relaxed on the ear but without losing clarity and distinctness. The last point, clarity could possibly suffer a bit with PIO, so that everything sounds buttery soft and nice to the ear but rose colored. Ok, only my personal testing can find out.

By the way, even the polyester caps gain after a break-in period. I think this might be the reason why Steve Guttenberg gave his Cornwall 4 a second review after a year. He was so excited about the added transparency and spaciousness. And I think that the caps could make the most development of all components (and of course the habituation of the person to the speaker).

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1 hour ago, captainbeefheart said:

 

If you have to choose use 2.2uF.

 

IF you want to retain the same type of sonics as the original type capacitors then get some PIO capacitors.

 

These are very good if you ask me and they are not very expensive either.

 

https://www.ebay.com/itm/353676391302?hash=item5258c17386:g:6psAAOSwajVURk76

 

I can't say I know what the original sonics would be like as my only experience is with this busted up pair.  I don't even know if the speaker that I deem 'good' is even good; it's just better than the other.

 

Since capacitors deteriorate with age, wouldn't these old stock potentially be bad as well?

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1 minute ago, gsgleason said:

 

Since capacitors deteriorate with age, wouldn't these old stock potentially be bad as well?

No, excellent crossover caps. I would first take a soldering iron and go over all the solder connections on the bad one. Just heat the old connections up and add a touch more solder to each one. 

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If you do choose to get PIO capacitors make sure they are hermetically sealed types, especially if they are NOS like the surplus Military types I suggested from Ebay.

 

For capacitors it's best to divide them up into dielectric types because that is where the difference in specs/performance is. As some suggested today's polyester film types have higher ESR compared to polypropylene which although are on paper is a much better dielectric in terms of the lowest dissipation factor (tan) which when multiplied by reactance gives you the ESR. Since reactance changes with frequency so does ESR, that's why it's best to look at a constant like dissipation factor or quality factor. In this case polypropylene are too perfect giving lower ESR which people have described as 'too bright'. I personally do not think I would be able to hear the difference in a double blind test but I have to agree, the PIO caps do sound 'correct' whether it's psychological or not I prefer them in my La Scala's and pretty much any heritage speaker I have heard with AA crossovers.

 

We played a cruel trick on one of my good friends that gets caught up in lots of the audiophile snake oil stuff and he wanted these extremely expensive capacitors installed in his Cornwalls with AA networks. I had installed all Electrolytic capacitors in the network 'back to back' to make them bipolar. He was blown away by the sound, honestly myself and another friend that was in on it were also completely baffled how good the speakers sounded. It sounded so good the friend other guy there had me do his Heresy I's all over with all electrolytics and again they sounded very good. They guy with the Cornwalls wasn't thrilled electrolytics were in his speakers and had me swap them out with the ones he wanted originally which sounded good too but I swear the lytic's sounded better for whatever reason. I wish I took some measurements of the boards with lytics to compare technically but I think we were all impressed with the sound and that's all that matters right.

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9 minutes ago, gsgleason said:

 

I can't say I know what the original sonics would be like as my only experience is with this busted up pair.  I don't even know if the speaker that I deem 'good' is even good; it's just better than the other.

 

Since capacitors deteriorate with age, wouldn't these old stock potentially be bad as well?

To have a reference, if I were you, I would first go the way I recommended and use new electrically "correct" polyester types. . Then you have an idea how the speaker should sound...also in its relation over the frequency band, timing, coherence.
Only in the second step (after several weeks) I would try PIO as a possibility of refinement or disappointment.

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1 minute ago, KT88 said:

To have a reference, if I were you, I would first go the way I recommended and use new electrically "correct" polyester types. . Then you have an idea how the speaker should sound...also in its relation over the frequency band, timing, coherence.
Only in the second step (after several weeks) I would try PIO as a possibility of refinement or disappointment.

 

That sounds fine, especially on the cheap.  I'm not finding them on mouser, however.

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17 minutes ago, henry4841 said:

…I would first take a soldering iron and go over all the solder connections on the bad one. Just heat the old connections up and add a touch more solder to each one. 


Yeah, this is solid advice actually. 

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12 minutes ago, gsgleason said:

 

That sounds fine, especially on the cheap.  I'm not finding them on mouser, however.

 

This (the list below) was by Mouser for Germany in Euro but the type number is the same worldwide, the upper position in the list is the 2.2 mF type made by Nichicon, 5% tolerance, not 10% as stated before.

 

Oh I see it works even as a hyperlink to be lead to Mousers‘s website.

As I said before, perhaps this very type is available with a „worse“ tolerance to select some pieces of slightly lower value than 2.2mF to meet 2.0mF.

 

I have 2.2 mF in my Lascala and so far (before I get closer values to 2 mF) I am happily satisfied as is.

 

 

Position

Mouser-Teilenummer
Kundenartikelnummer
Herstellerteilenummer
Beschreibung
Gewünschtes
Lieferdatum
Geschätztes
Lieferdatum
Menge Stückpreis
(EUR)
Gesamtpreis
(EUR)

1
http://www.mouser.com/images/icon_rohs.png1
647-QAK2E225JTP
QAK2E225JTP
2.2uF 5% 250V
MAI 10, 2021   6 3.68 22.08

2
http://www.mouser.com/images/icon_rohs.png1
80-A50IT4680AA60J
A50IT4680AA60J
250V 6.8uF 5%
MAI 10, 2021   6 4.83 28.98
 
1http://www.mouser.com/images/icon_rohs.pngRoHS: Konform
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Just now, Crankysoldermeister said:


Yeah, this is solid advice actually. 

 

I don't see any oxidation or corrosion, so I shouldn't have to remove the old.  I can certainly try this as it's very quick and easy.

 

I was also concerned with the negative bridge wire going across the terminals.  It's not shiny any more.  I'm wondering if I should try to polish it up or something.

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  • gsgleason changed the title to [FIXED] Cornwall 1 bad crossover help

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