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Capacitor measurement instrument suggestions

Drugolf

Drugolf

AK Subscriber
Subscriber
Since I am spending most of my time restoring speakers I would really like to get a good instrument for measuring the 3 key aspects of cpas. Capacitance, leakage and ESR.
Of course many techs have the various Sencor meters that do this but as I research those they can be costly when you add ESR and frankly they are getting a little long in the tooth considering Sencor no longer supports them.
What are some other options that provides all 3 measurements that can be trusted that you guys might recommend?
I may still end up back looking for one of the Sencors, but I may as well see what's out there that works well for our area of focus.
 
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What is your main objective in measuring?

I would remind you that even the best stand alone instrument may still not give a clear indication of a cap's performance under actual operational load conditions.

For the cost of setting up to do thorough analysis at actual power/load levels you can buy quite a few audio grade caps.
 
It is getting to the point for me that some of my speakers have some rather large caps and would be very expensive to replace. It is just adding up and being uncertain if they even need it make me uncertain. I can take them to a local tech to have checked with their instruments, but if I can ge into a similar device for a reasonable price, and this is my area of interest, why not have it available to me. There may be others that have odd values that are hard to replace without combining a bunch of others in difficult arrangements that if they are okay, I could just leave as-is. I don't wont to get into this debate on this though here. I understand the various perspectives on the subject well enough and I am curious if there is something out there worth considering.
 
There is, and it's affordable. I've got a Fluke 177 multi-meter and a Keysight U1732C LCR meter. The Fluke does values for capacitors, and all the other things you'd expect from a multi-meter. The Keysight measures ESR at 5 different frequencies, this is good. I bought one of those 99 dollar Blue ESR meters that you see all over the place. Do not buy any of those. They only test ESR at one frequency and is a waste of money, I need to sell mine. But I only have these because they were a gift from a friend. If I had to buy them, these two meters would probably be over 700 dollars.

The solution that's affordable is the DATS v2 speaker testing computer program and usb dongle. I believe there is also Woofer Tester, but I'm not familiar with that one. DATS is 99 bux and will test the value of your cap and give you the ESR at 3 different frequencies. It also gives a few other results. I've used it for testing vintage oil caps and modern poly caps, old and new electrolytics. The DATS system gives me the same results as my hand-held multi-meters, so there's that.

I did try to test the value/esr of a very small value capacitor, maybe .2uF or so. DATS couldn't deal with it, couldn't do it. But for standard capacitors you find in speakers, no issues.

The downside to the DATS system is that you need a windows system to use it.

http://www.daytonaudio.com/index.php/dats-dayton-audio-test-system.html

Biggles
 
B&K 879B for ESR and capacitance, Heathkit IT-28 for leakage (can apply up to 600V, doesn't give you an exact number but is pretty good for go/no-go).
When all is said and done you'll be at ~$350 though. That's a lot of caps, even big crossover caps...
 
I'll look into to that Biggles. I have a decent DMM already and have that covered, although I think the Sencor level instruments do even better in that area.
Does the DATS system do leakage testing?
 
The Smith and Larsen WT2 can measure uF, ESR and D.F. at any number of frequencies you want. I co-wrote and article with Keith Larsen of S&L for the May 2011 issue of AudioXpress about using the WT2 to measure capacitors. PM me and I'll send it to you. Not sure how valuable leakage is. The parameters I listed are the usual ones people worry about.
A second benefit of WT2 ownership is you obviously can also test woofers, mids for their T/S parameters. You can also measure inductors and resistors.
Below are a couple of downloadable .pdf files showing a bad and good cap test with the WT2 along with a sheet explaining the test output.
 

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Drugolf said:
I'll look into to that Biggles. I have a decent DMM already and have that covered, although I think the Sencor level instruments do even better in that area.
Does the DATS system do leakage testing?
Click to expand...

I would open up a conversation and talk to spkrdtr. To be able to talk to someone who's been down this road and can actually speak with authority and knowledge can be invaluable.

I'm not convinced leakage value is of much value, and I don't know if the DATS system tests for that. My guess is that it does not. If you get a high ESR on an old cap, toss it. Between ESR and value, you're golden.

However, if you buy new caps all this is pretty much moot. I do not reuse old capacitors, not even once.

Biggles
 
I do not know what you have invested in your speakers and components but whatever the new caps cost is nothing as to the improvement in sound of a good quality speaker with new caps!!!
 
drbiggles said:
There is, and it's affordable. I've got a Fluke 177 multi-meter and a Keysight U1732C LCR meter. The Fluke does values for capacitors, and all the other things you'd expect from a multi-meter. The Keysight measures ESR at 5 different frequencies, this is good. I bought one of those 99 dollar Blue ESR meters that you see all over the place. Do not buy any of those. They only test ESR at one frequency and is a waste of money, I need to sell mine. But I only have these because they were a gift from a friend. If I had to buy them, these two meters would probably be over 700 dollars.

The solution that's affordable is the DATS v2 speaker testing computer program and usb dongle. I believe there is also Woofer Tester, but I'm not familiar with that one. DATS is 99 bux and will test the value of your cap and give you the ESR at 3 different frequencies. It also gives a few other results. I've used it for testing vintage oil caps and modern poly caps, old and new electrolytics. The DATS system gives me the same results as my hand-held multi-meters, so there's that.

I did try to test the value/esr of a very small value capacitor, maybe .2uF or so. DATS couldn't deal with it, couldn't do it. But for standard capacitors you find in speakers, no issues.

The downside to the DATS system is that you need a windows system to use it.

http://www.daytonaudio.com/index.php/dats-dayton-audio-test-system.html

Biggles
Click to expand...

1+ on U1733C
But DER EE DE-5000 is inexpensive.
Please check out the discussion on eevblog forum.
 
I'm using this one and I'm very happy with it, and it also identifies all type of transistors, diodes, LEDs, thyristors.

Costs about $20.

Described here : http://audiolalies.blogspot.fr/2016/11/lami-du-depanneur.html (use Google translate)

1-P1180086.JPG
 
There are so many more options today than just a few years ago. The little $20 eBay boards are pretty good. If you build a simple interface for your sound card, the Visual Analyser software also contains a powerful LCR meter function. There are various hand-held units, plus the cap functions in many DMMs now. There are the older bridges available on the used market.

In your application (passive crossovers) DC leakage probably isn't important, but it's a good indicator of PIO caps going bad. Few modern meters in a sane price range include DC leakage. That's why vintage radio people tend to use vintage cap checkers like Sprague and such. ESR and dissipation factor (also power factor) represent the same thing and either can be calculated from the other for a given frequency. ESR is usually measured at a high frequency, say 100 kHz, and dissipation factor is usually measured at 120 Hz or 1 kHz. High frequency performance is fairly predictable from low frequency performance, so I don't worry too much about the format of the numbers.

There is almost no test equipment that will measure a cap under crossover operating conditions, though you could build something quite easily. I can't make a recommendation on what path to take, as many will serve your needs and you may or may not want to service an older piece of equipment. I like the boat anchors and would probably get a used GR 1650A as it offers a lot of flexibility. OTOH it's not some fancy digital thing that people are more comfortable with today. In that direction I'd probably take the Visual Analyser option, being free and potentially more accurate than almost anything else you could afford.

FWIW, I built a lot of speakers with no way to test caps at all. So may other factors had far more effect than a few percent difference in caps.
 
ConradH said:
There is almost no test equipment that will measure a cap under crossover operating conditions.
Click to expand...

QFT. The common ESR and capacitance meters use pretty low test levels that work OK for circuit-board levels, but not for higher powers seen by crossover capacitors.
 
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