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1983 Cornwalls


jeffryder

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I have recently purchased a pair of Cornwalls'. The serial numbers are 33Y972 and 34Y278. I took the back off to see what crossovers they have. I am confused as these have a 20 uf capacitor in them. Is this right? I am no expert on Klipsch but I have only seen 2 and 3 uf capacitors for these speakers. I have attached a picture. Thanks for the help in advance.

20210408_114028.jpg

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17 hours ago, jeffryder said:

I have recently purchased a pair of Cornwalls'. The serial numbers are 33Y972 and 34Y278. I took the back off to see what crossovers they have. I am confused as these have a 20 uf capacitor in them. Is this right? I am no expert on Klipsch but I have only seen 2 and 3 uf capacitors for these speakers. I have attached a picture. Thanks for the help in advance.

 

That looks like a B2 crossover.  Here's the schematic.

 

Mike 

 

 

CornwallTypeB2.jpg

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Hi @jeffryder

The capacitors of these networks evolve badly over the years, especially after more than 35 years. You should measure these capacitors to see the µF found and know if they are still within specification. If they are out of specification, consider changing them either by Klipsch aprouved or by replacing the same values in MKP 🙂

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  • Klipsch Employees
5 minutes ago, mustang_flht said:

Hi @jeffryder

The capacitors of these networks evolve badly over the years, especially after more than 35 years. You should measure these capacitors to see the µF found and know if they are still within specification. If they are out of specification, consider changing them either by Klipsch aprouved or by replacing the same values in MKP 🙂

...What should he use to test the caps with? ...Unless they are leaking oil, they are fine.....Never tested one in the lab, ove 22y, that was bad unless it was leaking.  Maybe heat up the joints on the network...as some of the points could need it. You may "hear" a difference once the caps are changed...but you can't test that...as unless you used the wrong part, it won't change. 

 

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6 minutes ago, Trey Cannon said:

Unless they are leaking oil, they are fine.....Never tested one in the lab, ove 22y, that was bad unless it was leaking. 

So what you're saying is that you've never measured a cap in the lab that had excessive ESR?  That's really hard to believe.  I don't have a "lab", but I have very good test equipment, and I have tested dozens of the old caps and almost every one had high ESR.

 

And I guess also what you are saying is that unless the caps are visibly leaking oil that there's no need to replace them, even if you don't test them?

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58 minutes ago, Trey Cannon said:

...What should he use to test the caps with? ...Unless they are leaking oil, they are fine.....Never tested one in the lab, ove 22y, that was bad unless it was leaking.  Maybe heat up the joints on the network...as some of the points could need it. You may "hear" a difference once the caps are changed...but you can't test that...as unless you used the wrong part, it won't change. 

 

Hi @Trey Cannon

I meant to measure the µF and possibly the ESR of these capacitors, but if you say that this does not wear out then disregard what I said.

 

You are the pro 👍

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On 4/12/2021 at 11:12 AM, babadono said:

????????

Depends on the quality of the meter IME.

...Yes, but not many can give enough AC voltage to test...due to the 9 Volt battery used to provide power.  The unit we use at Klipsch was 20K new, and still isn't that great.  MOST speaker network caps are 100 to 250V AC. 100 Watts @ 8 Ohms is about 28 Volts AC.  How often in the life of a speaker do you see truly 100 Watts for long times?  I was generalizing in earlier post.   There are AUTHORIZED REPAIR LOCATIONS, you don't have to use aftermarket parts and trust what others hear is better...you can use correct parts and Know... JEM performance audio. Crites and other are NOT authorized for any replacement part or repair.  Many will come to the defence of the aftermarket stuff... but facts are facts.

 

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Threads like these kinda bum me out.

 

I can't tell if my capacitors are out of spec because I don't know what the original specs were.

 

Even if I knew the original specs, my DE-5000 LCR meter can't accurately tell me if my capacitors are out of spec.

 

 

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On 4/9/2021 at 3:03 PM, jeffryder said:

 

 

Please take notice of the posts by @Trey Cannon  , he is a Klipsch Employee and the Reference  in regards to such  questions -

Aftermarket capacitors from all online sellers will alter the sound   , while OEM Klipsch capacitors are the sole to have the klipsch sound signature

 

 - the klipsch Authorized Repair center and reseller of OEM capacitors -    @JEM Performance     https://jemperformanceaudio.com/   

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On 4/13/2021 at 10:12 PM, Trey Cannon said:

...Yes, but not many can give enough AC voltage to test...due to the 9 Volt battery used to provide power.  The unit we use at Klipsch was 20K new, and still isn't that great.  MOST speaker network caps are 100 to 250V AC. 100 Watts @ 8 Ohms is about 28 Volts AC.  How often in the life of a speaker do you see truly 100 Watts for long times?  I was generalizing in earlier post.   There are AUTHORIZED REPAIR LOCATIONS, you don't have to use aftermarket parts and trust what others hear is better...you can use correct parts and Know... JEM performance audio. Crites and other are NOT authorized for any replacement part or repair.  Many will come to the defence of the aftermarket stuff... but facts are facts.

I understand your point very well. I have a 1977 Lascala with a Crites AA  Xover. I also still have the original crossover, but the capacitors are not really good in values anymore, at least the capacitance values are not correct, if only measured with a handheld meter and 9V. The Crites crossover uses modern capacitors. But the original sound I remember differently. My guess is that not only the material is different but also the Q factor. The new film capacitors sound very accurate but too sharp with the K400 and K77 Alnico.

I live very far from the Klipsch factory in Germany (but I have been to the factory in Hope :). I also believe that Klipsch no longer gets the original PIO car run capacitors.

So my question to the expert, I want to give the Russian KBG- mn PIO types or the K75-10 types a chance. You hear very good things about them in many forums (for what it is worth) and you can get these types for 10 to 20 USD. To just try it out would be worth it with. The Q factor should be identical to the old PIO Klipsch capacitors (for a 1977 speaker). What do you think?

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