Audio capacitors in a computer world.

[maluckey]

I just got a closer look at my wifes RMA'd board (KR7A-133r), and noticed, that it us now (upon return) using Nichicon capacitors near the AGP slot. I've not seen them in use in computer apps. before. Is this because of cost, or suitability?

The reason that I ask, is that I am an audio electronics hobbyist, and have Black Gate, Ruby con, and OS-Con caps all over the shop bench. They are undoubtably superior performers, so why not re-cap my mobo with them? Somebody said the tolereances for comp grade are different, but the Black Gates are rated at 10% to 105 degrees C.

 

[davesaudio]

NOTE:IMHO
you have posted in highly technical
you may end up with responses from the "can't measure it -doesn't exist" camp versus "voodoo magic snake oil this component evokes feeling in the music"
you have been warned (grin)

nichicon are generally considered good caps from an engineering perspective (ok, my engineering perspective) - i think the oscon as well.
is black gate any better in a digital circuit? according to who?
figure out how much a motherboard of black gate would cost you....

 

[Mark R]

It may be due to cost. Motherboards are designed down to a cost - every penny is saved.

However, computer grade capacitors need a number of properties that audio capacitors may not have - They need to have extremely low ESR and ESL values - this is particularly true of the capacitors serving the AGP and CPU VRMs. They need to have extremely high ripple current rating at a frequencies of up to 1MHz.

The ESR/ESL are probably the most important parameters (probably more important than capacitance) - and the reason for having 6 or 10 in parallel is to get the ESR down - it's often cheaper to use 6 electrolytics instead of 1 tantalum cap - The electrolytics offer about 20x the capacitance, but that certainly doesn't hurt. The ESR needs to be low because the circuits are tweaked to respond quickly to sudden changes in load (e.g. A CPU might be using 20 A, and then 1 us later be demanding 40 A). A low ESR will affect the feedback loop and cause the circuit to oscillate completely losing its voltage regulation ability and possibly destroying whatever it is supplying.

You could always try changing the capacitors, but find out what the ESR and ESL of the Nichicon caps are. You also need to know what the tolerance of the ESR/ESL is with temperature - these rise as the caps heat up. If your caps have higher values for these critical parameters, then they will offer poor performance (and possibly even not work at all).

 

[maluckey]

You all may be right, in many aspects...............

I talked to an electronic engineer friend of 15 years, after posting, as he stated as far as cost goes, it only makes sense if the caps are, with the motherboard, cheaper than upgrading. He liked the Nichicon, the Os-Con, and all, and gave the two thumbs up for the Black Gates, but also mentioned that the cost of Black Gates is more than the Motherboard.

I hear from an OC'er that I respect, that for all the money spent, they may give 2-4 mhz FSB at the extreme, for 100 dollars. Not good math in my book. Oh Well! No free lunch today.

 

[CTho9305]

You're planning to "upgrade" the caps on your motherboard? Or replace damaged ones?

 

[maluckey]

I was planning a little of both, before, but now, I'll wait it out until whatever the Via KTXXX that is available when this one dies.

 

[PrinceXizor]

This is a semi-on topic thread crap (hmm...is such a thing possible?)

I have a powerleap connector where one of the capacitors on the independant power circuits came loose (and on futhere inspection is probably crap (deformed bottom)).

Unfortunately, there is no specific p/n on the cap so I can see ALL of the specs to match it to a new one.

Its a 2200 uF 6.3V rated at 105C from NKCON.

I'd like to get one of these, but I am worried about the ESR issues as mentioned in this thread. I'm fairly certain this would qualify under the "CPU VRM" area as mentioned in a previous post.

Suggestions?

P-X

 

[maluckey]

That's what the Nichicons are near the AGP slot on my Abit board read. No part number either.

There are hundreds of afticles I found over the weekend about caps, especially the High-end ones, and they all would fit the bill in computers, but would drain the wallet for more than the cost of the motherboard itself, and that's at discount, and not full retail!

 

[PrinceXizor]

well...I'm not going to go crazy....I work in an electronics place and we have some cats from digi-key and allied elec...etc...plus other electrical suppliers...what I need is what type of low ESR and ESL do I need relative to temp. etc. i.e. a datasheet to match. I figure these things cost a couple of bucks at most (one I found I'm sure works, but is sold in production qtys. at abou $.20 a piece....too bad.

Does anyone have a datasheet on these particular caps?

P-X

 

[Mark R]

I'm sure the caps will have a series code on them.

On my Abit the CPU VRB has 2 banks of caps - one is Rubycon 16V 1000uF ZL series caps (probably the input filter), and the other bank is 6.3V 3300uf MBZ series caps. Similar MBZ series caps are scattered around the AGP slot.

The ZL is a high-performance capacitor, but the MBZ is Rubycon's brand-new premium capacitor series.

 

[PrinceXizor]

The only thing on the package is the following info...

NKCON
2200uF
6.3V
105C


And a strip indicating the negative lead.

That's it. I wish there was more.

As far as the caps you mentioned. Can you post datasheet links? Thanks!

P-X