PSU filter caps (groan)

[Dreams]

So our console turned 30 this past January. For the big three-oh, I want to give the little guy some fresh filter caps. I've never really dealt with PSUs of this size before, and I just wanna check before I do something stupid.

SO...

The supply in question is the audio supply (bipolar 18v) for an MCI JH-618. There are four 8700uf 40v screw terminal caps in the supply itself, and two more inside the console. I wanna put 10,000uf 50v caps in to replace them.

NOW...

Screw terminal caps at that rating are, say $27 compared to snap-in caps at that rating which cost say, $7.

See where I'm going with this?

It looks like the major difference between the two types is the ripple current rating. Is there a benefit, electrically, to using the screw terminal caps with the higher RC rating in this application? Maybe just the first filter section?

Anything else I should consider when choosing PSU replacement caps?

Tanks.

 

[PRR]

You don't want to think cheep on a board like that.

However: Use the snap-caps, if you can connect cleanly. The screw-caps were IMHO never such a good idea; modern snap-caps are very-very good.

Just saying what I would do. Obviously don't click ORDER until someone posts an opposing opinion.

 

[Brian Roth]

The caps inside the desk should NOT ever have to deal with ripple current since they are connected across the filtered/regulated DC rails.  But, perhaps you could post links to the data sheets for the various replacement caps you are considering.

Best,

Bri

 

[ricardo]

There is a BIG caveat for replacing screw terminal caps with snap in PCB mounts.

Electrolytics have a vent which must be UP.  On most screw terminal caps, they are at the terminals.  On most big PCB mount electrolytics they are on top.

If they are the wrong way round, when the cap gets hot (which they will on a big PSU) the electrolyte will be squeezed out and your nice new caps will have very short life.

 

[Dreams]

Thanks everyone.

I don't want to think cheap. I want to think economically.

I'd rather spend 20 extra minutes hooking them up than $100 extra dollars. IF there's no reason to.

I've read good things about the snap-in caps, but I read it on the internet, so... Just wanted to check here.

If I went with them, I would connect them using those crimp...terminal...thingies (think speaker cab) crimped tightly around both the wire and the cap terminal, then soldered. Better ideas?

Brian, I had thought that those two caps inside the console were probably not filter caps as such, but my expensive, poorly photocopied manual doesn't quite show just what they do. Or where and what they are connected to. Are they basically just "reservoirs" for the +- rails?

Cap orientation. That's a good thing to watch. I hadn't thought of that, and thanks for chiming in with that.

As far as data sheets go, I'll try to do that today, but I've got a lot to do today and not much time to do it. I downloaded the sheets for every cap series in that approximate range that Mouser carries. Excessive, yes. I'll sort through those and see if I can remember which ones I was looking at.