amp blew a capacitor need help selecting

[3l3phantstomp]

Good people of Talkbass,

My Orange Terror Bass 500 blew and the capacitor is a 3300 uf 16v made by Honsing. I'm not partial to the mfg but after researching them I'm not sure which. Temp tolerance is -40 +105c. Mouser.com has different variance levels on theirs and I don't know which I need or if they are audio grade. Appreciate any thoughts.

[B-string]

Why you worried about "audio grade" in a power supply cap? Get a higher working voltage if you can for the physical size limits. 85c should be fine working temp.

[--Vissinger --]

just get something that matches the capacitance/voltage spec from a reputable manufacturer. This sounds like a power supply cap, so the tolerance isn't particularly important and there's no such thing as Audio Grade.

If you're a worrier, get a tighter tolerance spec but it makes no difference.

There's probably two of them. It would be good to replace both.

[Mr. Foxen]

You can go higher on either, but try not to go too much higher on capacitance, just need it to fit in the space. Chances are the voltage being borderline was the problem to start with.

[12bass]

If space is not an issue, a 25 V 3300 μF 105C capacitor may be a good idea for replacement. Panasonic FM series is good, IMO, though they have a newer line which is even better.

[Oobly]

Look for a low ESR, 105 degrees capacitor with the longest lifetime rating you can find.

In general an electrolytic capacitor's lifetime is halved for every 10 degrees C it goes up. So, a 105 degree rated cap with 10000 hours rate life will last more than twice as long as an 85 degree cap with the same rated life.

Lower voltage rating electrolytics usually have lower ESR's, too, so it MAY be best to stick with the same rating.

In short, 3300uF 16v with low ESR, long lifetime rating at 105 degrees. Panasonic and Nichicon are good, something like this should be good: http://www.newark.com/panasonic/eeu-...16v/dp/74R3422

[3l3phantstomp]

SO many thanks for this. Not a worrier now, since I watched the damn thing blow on standby. I just lacked the knowledge and only had an aluminum cap shell to work with (fired off like a bottle rocket inside). Its five months out of warranty so I'd prefer to take a stab first than pay shipping and labor for a cap blasto. I'll replace both. Is there a thread for pics of amp gore?

Thanks for taking the time. Two beers on me when ye round ze 'natti way.

[beans-on-toast]

When you are installing the new cap, take note that it is polarized. One of the leads has a (+) on the side of the cap case. Note where the (+) lead is before you remove the old cap and install the new one the same way. You don't want to install it backwards.

To add to what others have said, a tolerance of +/- 20% is better than one that is +/- 50% for example. If your cap has a tolerance of +/- 20% and the measured value is within a 3960uF to 2640uF range, the manufacturer assigns it a value of 3300uF. A higher tolerance cap generally costs more but is closer to the 3300 target value.

[Cirk]

I'd guess that there are some folks here who would like to see pictures of wrecked amps. When I fixed radios for the National Guard, I got one that had been hit by lightning down the antenna. It looked interesting, but the smell was horrendous. I don't think I could have held my nose long enough to take a picture. Glad those cases seal well. The only word I wrote on the repair tag was "slagged".

[BassmanPaul]

Do you still have a warranty on the amp??

Edit: Sorry missed post 7.

[bgavin]

I'm a computer tech, not an amp tech. I do a lot of board repairs for bad caps.
That said, my advice is steer clear of Chinese caps, in favor of the top brand Japanese.
Panasonic, Nichicon, Rubycon, and so forth.
For singles, search for The Cap King.

As noted above, opt for the 105C rated caps.. they do better in the heat.
Amps generate heat. Play the amp outdoors, summertime... more heat.

[3l3phantstomp]

This site cannot be beat. I cannot thank you all enough for all of this insight. One question: someone on the Orange forum mentioned to beware of a corrosive liquid that may spray out from the cap when it went. He said an older amp of his blew and it was everywhere. Safe to assume that was 70's cap construction materials? I saw no fluid or even rogue marks surrounding the cap upon inspection. Just unrolled paper/metal coil.

I ordered two of the reccomended Panasonic caps Oobly reccomended. Much appreciated for the polarity tip Beans-on-toast. And when we talk "more expensive" when it comes to caps, we are talk a difference between $.50 and $1.50. No sweat when needing two. Most likely different repairing motherboards, TV boards, which may require a greater number.

[B-string]

Older caps used an oxide paste. New production are dry.

[3l3phantstomp]

B-string B-delivering the goods again!!!!

[RS66LB]

It would seem obtaining a cap that has a tighter tolerance (5% instead of 10% as example) would be a good start, also using a cap with a higher voltage rating (at the same capacitance) would help as well. Either way good luck.

[two fingers]

Originally Posted by 3l3phantstomp

B-string B-delivering the goods again!!!!

Nothing new there. I usually try to see what B, Beans, Nashville Bill, or Line 6 have to say. All of them are usually right. B just somehow is right with less words.

[3l3phantstomp]

I just hope to return the favor one day. That's why I'm trying to make this as detailed as possible for the future searchers. Will include photos later on. Then cross-post it to Orange's.

[3l3phantstomp]

Also, this one year warranty future we live in kinda brings me down. But then I think about what I've learned in the last 48 hours and I feel better off. I guess I feel that way because its just a cap...and I'm driven to fix it. I could have...bought the second year warranty...the retailer warranty...aftermarket extended warranty...but none of that is the manufacturer standing by their man, imo. O isn't the be all end all of amps, don't get me wrong, but its not an entrance level piece of equipment (IMO). But I'm also not a rawkstarr so a $700+ piece of equipment really effing matters!

[beans-on-toast]

Originally Posted by 3l3phantstomp

someone on the Orange forum mentioned to beware of a corrosive liquid that may spray out from the cap when it went. He said an older amp of his blew and it was everywhere. Safe to assume that was 70's cap construction materials? I saw no fluid or even rogue marks surrounding the cap upon inspection. Just unrolled paper/metal coil.

The old caps used to sometimes explode and make quite a mess inside the chassis. If you look on some caps you can see a rubber circle that blows when the pressure inside the cap get too high. If you see this bulging, it is a sign to change the cap. On smaller electrolytic caps one end is designed to blow.

Even if you can't see anything where the cap blew, I like to wipe the area down with a Q-Tip and alcohol just in case there is any residue.

[bgavin]

Gas tanks run dry, tires wear out, girl friends dump you and move on.
Electrolytic caps die of old age. It's the way it is.

I offed my Mitsubishi TV because it needed a recap, and I didn't feel like recapping 150 teenie caps.
My daughter used it in in a music video, where her band beat the TV to death.

Installing a higher voltage cap than required is a waste of effort.
If the OPs 16v cap is operating in a 12v circuit, it is pointless to install a 25v cap.
If the 12v circuit is over voltage, fix that problem.

If it is a crap design, i.e. a 16v cap in a 16v circuit, adding the voltage headroom is a good idea.
1970s vintage is before the era of Cost Cutting, so I'd be surprised if the defective cap was a cost-reduced item.