Electrolytic caps

[miltown]

I have an old electrolytic cap that says 10+10 MFD. I understand the ratings but it is one of those caps that has 1 ground lead and 2 + leads. Can I replace that with 2 10uf elec. in parallel. THat is what this cap seems to be. Does anyone have a better explaination of these caps.

paul

[Kazooman]

It is just what the label says, two 10 MF electrolytic caps in a single housing. Both caps have their negative terminal attached to the can (ground)lead. They are not really in parallel, since the positive leads are not connected (they COULD be connected in parallel if one chose to do so to make a single 20 MF cap).

Yes you can replace them with two individual 10 MF caps. The positive leads would be attached to the leads that go to the current can and the negative leads would then go to ground (probably, but not necessarily, at the same point).

You can find replacement multi-section electrolytic caps from many suppliers (Antique Electronic Supply for one). You may need to purchase an adapter ring to mount the can to the chassis. If you want to maintain the original looks, you can try to carefully open up the existing can and take the guts out. Clean it carefully and then you can install your two new 10 MF caps inside the can (if you find two that will fit).

Whatever you choose, be certain to check the voltage rating on the can and get caps of equal or greater size.

[Chuck H]

Just to add... It was infered but not clear that IF the two + leads were together so that the two 10uf sections are in parallel you could also replace that cap with a single 20uf cap. 22uf is a common value and would be fine.

Though I can't imagine why someone would choose to parallel a dual 10uf cap instead of use a single 22uf. So be sure about how the cap is wired before replacing it with anything.

[miltown]

Well there somewhat parallel. There is a voltage divider between them and another voltage is tapped between the voltage divider. The cap is the original cap. It is in a silver tone 1331. Obviosly the one and only filter cap. The schematic can be seen here Silvertone 1331 schematics | Flickr - Photo Sharing!. Right off the cat. of the rec. tube.


paul

[Chuck H]

Those are the main filters in that amp. They are not parallel BECAUSE there is a resistor between them on the + terminal. In that amp "I" would replace them with a pair of 22uf caps. You shouldn't notice any difference in tone but they will perform better.

[miltown]

Thank you!!

paul

[Kazooman]

The question I would have is why did all 3 go bad? Either a bad batch of caps, or a bad design that subjected the caps to too much voltage or too much heat. I'd up the voltage to 50 volts if you can. Check the temperature in the area.

Or, more likely, there may be a bad diode or some such that caused the caps to be subjected to AC. look around the caps for any rectifiers and check those with an ohmeter.

There seems to be some confusion. The schematic the OP provided shows TWO caps (in the one can) and they are already at 450 volts. I assume that the OP's amp is an original Silvertone 1331. It is a very old amp and it is well past time for new filter caps.

[miltown]

Yeah I'm confused by that post. I'm doing a overhaul of the amp. By the what is OP stand for?

paul

[Mark Hammer]

OP = original poster = the person who starts the thread.

[Kazooman]

Yeah I'm confused by that post. I'm doing a overhaul of the amp. By the what is OP stand for?

paul

OP = original poster

[J M Fahey]

Hi Miltown and Kazooman.
Don't worry, that "confusing" post is synthetic, not human written.

[Enzo]

Even so, there is no real confusiion, they all go bad because they all are 50 years old. Nothing further to read into it.

[Chuck H]

Why don't you think a human can be a post? Posts can be long if you want to cut them. The ends that go in the ground should be coated.

[Enzo]

Ooooh, that whole Vlad the Impaler thing?

[Chuck H]

Enzo, I'm set for "linear" viewing also. But if you look at the "threaded" view you'll see I was responding to JM.

Just didn't want the humor to get lost.