Cornwall I restoration

[ronajon]

no problem. i'm happy to try as long as nothing breaks or blows up 😉

 

so then the tweeter still is on tap5 (coming from tap4) together with the 4uF capacitor and the squawker goes to tap 4 ?

 

i'll try that tomorrow, lets see what happens.

 

should it be possible to test with the rear open, so i can just temporarily slide the squawker in the hole of tap 4 because of the de-soldering of the tweeter there and A/B test ?

[mboxler]

Yes leave the tweeter on tap 5. Squawker to tap 4. Unfortunately if you leave the back off you’ll loose some base. I’d put the back on with only 4-6 screws to ease the process. 

[mboxler]

The 4uf capacitor may be too small to work properly with this last change but as always let your ears be the judge. 

[John Warren]

It's dB (capital B for Bell as in Alexander Graham).

[ronajon]

update time

 

i've got my hands on an ESR meter, so time to test the caps.

 

1 box measures 0.142Ohms on the 4uF cap, and 0.282Ohms on the 2uF cap

the other box measures 0.132 on the 4uF and 0.301 on the 2uF

 

are these caps within spec or is it time to replace them ?

 

meanwhile i also acquired a set of K77-M tweeters so i'm installing 1 together with the Crites CT125 from @KT88 to do some A/B testing coming days

(the other K77-M has a busted voice coil due to a displaced pole )

[KT88]

At which frequency did you do the ESR test? I am just curious but also the experts need the frequency to judge your measurements, I think. Did you also measure the capacitance which is the basic information?

Just as a check, you have to disconnect both wires of the capacitor before measure it.

[ronajon]

i've got this cheap meter from Amazon where i was not able to set any parameters (frequency, voltage, etc)

if i'm correct, with this meter it should be possible to measure in-circuit.

 

i did however tested with and without the wires connected to the rails, results were almost the same

 

ps. i have no idea if i'm testing the right way. so if there's any expertise who can describe what is the best way i would be very greatful

 

 

[Deang]

That capacitor is probably bad. If you measured using 120Hz or 1KHz, that reading would be 3-5 times higher. 

[ronajon]

10 hours ago, Deang said:

That capacitor is probably bad. If you measured using 120Hz or 1KHz, that reading would be 3-5 times higher. 

i'm measuring with 100KHz (says it on the meter ), in-circuit

 

4uF caps: 0.132 & 0.142 Ohms

2uF caps: 0.301 & 0.282 Ohms

 

you're saying all caps are bad and should be replaced?

[opnly bafld]

2 hours ago, ronajon said:

i'm measuring with 100KHz (says it on the meter ), in-circuit

 

No way to adjust the meter and measure at the frequencies Dean mentions?

 

[ronajon]

no, unfortunately not. the meter just has 100KHz (MESR-100)

i'll see if i can test with another meter soon

 

what are good specs for the 2 and 4 uF capacitors ?

[ronajon]

sure not making this a thread about capacitors, just trying to get my speakers in an as good as possible condition again

 

i got the opportunity to test with a better meter today, the Peak ESR (same as @henry4841 mentioned ) together with the DCR of the tweeters (suggestion from @OO1)

 

on the left speaker

2uF cap: 2.19 uF / 0.97 Ohm ESR

4uF cap: 4.18uF / 0.37 Ohm ESR

DCR of the tweeter: 6.7Ohm

 

right speaker:

2uF cap: 2.09 uF / 1.02 Ohm ESR

4uF cap: 4.25 uF / 0.36 Ohm ESR

DCR of the tweeter: 6.7Ohm

 

this seems to be within specs ?

if so i can move on to figuring out how to veneer the cabinets 😀

 

 

Edited December 1, 2023 by ronajon
other member

[ronajon]

23 minutes ago, OO1 said:

it's @OO1   Perfect all around ,  for the K-77M   6.7 Ohms DCR is fantastic 

oops, changed it.

 

 

[Deang]

Another meter that uses 100kHz. 
 

This is from the manual that came with my B&K 880.
 

Also a chart. Notice how the ESR decreases with frequency - regardless of the dielectric material. 
 

 

[Deang]

Using the chart, one can see why measuring at 100kHz doesn’t make much sense for capacitors used in loudspeaker networks. 

[ronajon]

i can understand when your in the business of capacitors / crossovers building and selling like Dean does, the testing equipment should be as good as possible.

 

I've looked at the b&k Dean mentioned, the retail price of that meter is 500EUR against 90EUR for the Peak Atlas.

For home use, and testing my speaker capacitors just once (or perhaps twice) the costs of a professional meter is too much.

 

 @Deang in your professional opinion, what is the frequency the capacitors for our speakers should be measured at?

In the specs of the b&k 880 the selectable frequencies are 100Hz, 120Hz, 1kHz, 10kHz, 100kHz.

assuming that (from the image you posted), 1kHz is for capacitors smaller than 0.01uF and 120Hz for capacitors larger than 10uF.

[Deang]

@ronajon I use 1kHz for the smaller values and 120Hz anything above 4uF. The spec sheet for the capacitors Klipsch uses states 1kHz for their DF spec.

 

 

[Deang]

@ronajon
 

The first picture is a 2uF measured using 1kHz. The second picture is the same can measured at 100kHz. 

 

This particular can is also sweating, with a light film on the outside that you can feel and smell.
 

A new 2uF Tecate measures .42 - .45

 

It’s just my opinion, but I think this part is nearing the end of its life cycle.

 

Some are fine for use while others are not. While you don’t have to replace them, the network will be back in spec, and the speakers will sound better if you do. 

 

I don’t sell capacitor kits. Please contact JEM if this is something that interests you.

 

 

[JEM Performance]

2 hours ago, henry4841 said:

And you are the Klipsch authorized dealer for crossovers and capacitors.

Can we get something corrected here?  Dean is not the authorized dealer for Klipsch capacitors.  Dean is authorized by Klipsch to build new vintage Klipsch balancing networks to Klipsch specifications.  Dean also installs new capacitors in some of the vintage speakers that use pc board networks.  My company, JEM Performance Audio, is authorized by Klipsch to offer replacement capacitor kits for the vintage Heritage speakers.  I also install the kits if need be in the hard wired networks.

 

Dean and I offer services that keep the vintage Heritage speakers operating as Klipsch intended.  These arguments about capacitors here on the forum are ridiculous.  We have available the correct parts to build and service Klipsch vintage balancing networks and yet we have those that insist on nit-picking 40+ year old capacitor specifications.  Those capacitors are old, they are degrading and who cares how much life is left in them?  If you want your speaker operating at peak performance, replace the capacitors with the genuine replacement part and your speaker will sound as it was intended to sound for another 40 years.  The kits are not that expensive and once installed, you probably won't have to worry about them again in your lifetime.  Why wait for the inevitable degrading that is already taking place to get worse?  I think some common sense is in order.   

[KT88]

18 minutes ago, henry4841 said:

I seem to remember a representative of Klipsch not so long ago saying on this forum say that the capacitors in Klipsch speakers are good for the life of the speaker. 

 

The fact is techs that make a living working on vintage audio gear seldom if ever replace film caps. They rarely fail unless one wants to go back to the 30's and 40's and possible the 50's where the old paper caps were used. 

 

 

 

 

 

 

 

Sorry, but now you're exaggerating a little, Henry. My Aerovox were already leaking oil 15 years ago and had very poor ESR values. The capacity was also no longer correct. We are 15 years further on! I'm not saying that it's always like this, nobody here is being asked to replace their original Aerovox if they are dry and the listener still likes the sound. But that is now the exception rather than the rule. 
The fact is, you have accused Dean of trying to persuade someone to buy new caps when everyone here knows that he is not the Klipsch caps dealer.
Furthermore, you refuse to recognise that an ESR measurement at 100Khz is completely irrelevant for the ESB in the audio range. 
I thought your last post was meant to be conciliatory, but it starts all over again. Let's use this space politely and respectfully. After all, we are invited by Klipsch to share experiences here. This is not "social media" where one insults the other. Sorry, I'm not directly involved, but it's getting on my nerves.