Should I be concerned?

[Leonc]

I'm a novice/tinkerer and I'm completing my first "cap job" on an amp.

I'm working on a '63 Gibson Falcon amp. I've replaced the electrolytic caps. There was originally a 20/20uF @ 630v multi-section cap doing the initial filtering off the power. It had been replaced by two individual caps that weren't performing right. I just put a new 33/33uF @ 630v multi-section cap in and the amp sounds great. It's the kind of cap with two positive leads coming out one end and a common negative coming out the other.

The problem is that the way it is situated, the legs are not quite long enough to go where they need to go and have the cap in a position where it's not touching anything. Right now, the side is just barely touching the chassis cover that screws in place. Also the legs are twisted in a rather awkward manner and are all exposed (no insulation).

There's a lot of juice going through this cap and I'm concerned about heat and or the possibility of it shorting out after getting jostled the wrong way on a move or something.

If you've encountered similar situations...how concerned would you be and what would you suggest doing? Should I extend one or two of the legs with some wire rated at 630V? Solid or stranded? Is there a type of insulation you think I should use on the legs?

[donnyjaguar]

Just solder on some extensions and put heatshrink tubing over it.

[Giraffecaster]

is there any way you can take a picture?

are you concerned that the case of the capacitor is touching the chassis or the lead is touching?

[hasserl]

It's possible that vibration could cause the screw to wear against the body of the cap, possibly into the layers and cause a short. This would not be good. I'd try lengthening the leads soyou can position it correctly. Use some heat shrink tubing to insulate the leads. It not only protects against accidental shorts and shocks, but looks much neater too.

[BJF]

Hi,

Right since I happen to like Gibson amps

OK make sure you fasten this cap to chassis with a capacitor clip so that the body of the cap takes the vibrations and not the leads.This to make sure the cap does not have it's leads torned
down the road.

You can easily lenghten the wires if needed.
Make then a hook at the end of the original wire and a similar hook at the extensionwire and make a solid mechanical connection of these hooks and the solder and make sure solder enters just under the isolation of the wires and then isolate with shrinkwrap.
Likely you would best use stranded wire rated at 630V's 105 degrees Celsius so there would be no mechanical strain.

None of the outgoing wires from this cap should touch anything.........

"Right now, the side is just barely touching the chassis cover that screws in place. Also the legs are twisted in a rather awkward manner and are all exposed (no insulation)."

A picture would help a lot here ...........sounds like maybe you should be concerned.

Be well
BJ


Affilliations
www.bjfelectronics.com
www.mpamp.com

[Leonc]

Clearly I assumed I should be concerned and it appears that was the correct assumption . Anyway, I put longer "legs" on the big cap tonight, insulted in heat shrink, and feel much safer now. Thanks for your suggestions everyone!

[donnyjaguar]

Sometimes I've had projects where a high-potential existed between two parts that probably never would come into contact with each other, but.... for these you can get this stuff called "fish paper". Its a very thick fibrous sheet that may be cut to size and provides and electrical barrier between parts. It seems to be more popular in older consumer grade products.