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Cap Recommendation for Speaker Amp

post #1 of 18
Thread Starter 
I've got a Jungson integrated amp that has at least one and maybe two capacitors that are swollen. These are part of a bank of 16 caps for, I believe, the power supply. I was thinking of replacing the swollen or maybe all the caps with some up spec'd caps. The current caps are branded "Capcom" and are 10000uf, 50v, 105deg..

I was told to go to a 63v version but not sure what brand or if it matters.
Any recommendations?

Thanks in advance
post #2 of 18
I would stick to the original spec of 50V. When it comes to electrolytics, the properties of the cap are best when operated near its rated voltage.
post #3 of 18
Thread Starter 
I was thinking that maybe the original caps were under spec'd, hence the swollen or compromised caps. This amp is a 80w/channel supposedly class A amp.
post #4 of 18
Hmm... do you know the voltages that the caps run? If you use high quality caps, then they will last longer. 63V is fine in my experience, but in order to minimize ESR and ESL it's best to use one with closer voltage rating to actual voltage. Electrolytics exploding in power supplies is pretty common because usually companies use crappy ones. If you can fit it, get the ELNA Cerafines. They last several times longer than other electrolytics and are better all around.
post #5 of 18
The only thing you give up with a higher voltage rating is size and cost. The specs actually improve with higher voltage tolerance. While they are definitely high quality caps, there's nothing about Elna Cerafines that says they last longer, either.

I do agree that there are a lot of bad quality caps out there, and it can be next to impossible to tell whether your caps blew because the voltage went above rating, or because the caps were of bad quality. That said, if you're going to spend the money to replace that bank of 16 - might as well be safe and go up a rating threshold to 63V. You have to be careful that they will fit, though, because the higher voltage caps will be bigger as well.

As far as I know, you will not find an Elna Cerafine at 10,000uF and probably couldn't afford one if they made it - certainly not 16 of them! In fact, you may have more than a little trouble finding a 10,000uF cap at 63V. Those are typically of the snap-in variety.

DigiKey appears to have several in the United ChemCon brand and some Panasonic "TSU". Mouser has several it appears - caps by Nichicon, Mallory, or Xicon, all of which are reasonably good quality caps for your application. At these prices (~$5-$9 per cap), probably the best thing to do is search from those brands for something that fits.

You might refer to BadCaps.net for information regarding other brands that have a propensity to blow. I believe I've seen "Capcom" listed among them before.

Good luck.
post #6 of 18
tomb, I have right in front of me four 10000uF ELNA Cerafines... proof they do exist! I remember reading a paper on electrolytic capacitors showing that distortion increases when the voltage is either too low or too high compared to its rating. The inductance and resistance also increased. Thus 16V capacitors will like to see a voltage of 8-16V. This only applies to cheap electrolytics, though.
post #7 of 18
Quote:
Originally Posted by cotdt View Post
tomb, I have right in front of me four 10000uF ELNA Cerafines... proof they do exist! I remember reading a paper on electrolytic capacitors showing that distortion increases when the voltage is either too low or too high compared to its rating. The inductance and resistance also increased. Thus 16V capacitors will like to see a voltage of 8-16V. This only applies to cheap electrolytics, though.
10,000uF @63V? That's a big difference. I'm willing to stand corrected if they really exist.

EDIT: According to Elna America, "Cerafines" are available in sizes from 6.3V to 100V and from 0.47uF to 6800uF.
post #8 of 18
If you made an extreme change in voltage rating, say using 200-400 or more volt caps where they were originally spec'd for 50V, you may have some inductance issues except I doubt an amp this well endowed doesn't even have more local decoupling, it's unlikely the change to a higher rating like 63WV would be anything but a positive change. Distortion is not a factor here. Resistance does not increase, ESR goes down with higher voltage (in same line of caps, we pretty much have to compare apples:apples).

You cannot just substitute Cerafines, they are significantly lower capacitance density and simply will not fit, unless you are willing to give up a lot of capacitance, and it might not be all that bad since 160,000 uF is quite a lot unless it's the entirety of the PSU, no regulation stage.

With 16 caps you will have quite low ESR already, the primary factor may be what space is available, and given it's likey to run warm, that they're still rated for 105C.

You might consider something like Panasonic TS series, here's Digikey's PDF for them, see also the cross-reference to other brands at the top for other ideas. You'll have to wade through it to see what'll fit dimension wise, I would stay with at least 63WV rating or 80V, dropping capacitance a little if necessary to make them fit (sometimes, better caps are a larger physical size for the same temp, voltage and capacitance rating).
post #9 of 18
Just thought I'd mention if you use Panasonic TS-HA, I have two 18,000uF/63V ones in front of me, given the size they have 2 extra legs to make them more stable. May need to cut them off, no biggie just thought I'd bring it up rather than you finding out when you get them, if you do. Can't recommend them or not as I haven't used them as of yet.

Some smaller TS-UP I have that are 2200uF/35V, don't have the extra legs.
post #10 of 18
Quote:
Originally Posted by tomb View Post
10,000uF @63V? That's a big difference. I'm willing to stand corrected if they really exist.

EDIT: According to Elna America, "Cerafines" are available in sizes from 6.3V to 100V and from 0.47uF to 6800uF.
Yes, I have four 10000uF 63V in my hands right now, about to install them into my headphone amp!



There are also equivalent Blackgates, too. Also, there are the 15000 ones:

post #11 of 18
ELNA Cerafines and Blackgates are DRY electrolytics, so they should last pretty much forever, whereas all other capacitors are based on wet ion solutions and degrade over time. Personal experiences from myself and others much older than me confirm this.
post #12 of 18
Well, mono and I are in agreement about the application, but ya got me on the existence of the Cerafines - didn't know they made 'em that big.
post #13 of 18
Depends how big you're hands are I guess but the Panasonics I mentioned above are quite a bit smaller than those cerafines, larger capacitance and higher voltage too, so as said doubtful they'd fit.
post #14 of 18
Thread Starter 
Here is a review of the Jungson by Head-fi'er Chillysalsa on AA. A picture of the capacitor
bank is in the fourth picture at the bottom:

http://db.audioasylum.com/cgi/m.mpl?...on&r=&session=

I don't think the Cerafine and Blackgates pictured above, would fit .

Thanks for all the rec's. The Panasonic's had been recommended to me before.

tomb, thanks for the link to badcaps. Looks like I'll spend sometime there these next few days.
post #15 of 18
OT: A bit shocking that with an amp in that price range they're using dodgy caps and also the bent heatsink fins are a little unpleasing aesthetics wise.

They're all cerafine btw.

Measure the caps in there and start looking at datasheets to see what will fit. Often they have more than one case size, like they may have a thin and tall size and a short and fat one, well relative to each other that is. The specs do also usually vary slightly with the sizes although that is not a major consideration compared to if they'll fit on the board or not.
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