How much capacitance?

[Axtman]

I am working on an old solid state Sunn Coliseum 880 amplifier. It has old large leaky power filter caps. The original values are 6900uf at 75v. What value capacitor should I replace it with? I am trying to find a capacitor with a 2 inch diameter so I can use the original claps.

Thanks,

[The Dude]

6,800uF is the closest common value cap. I found these (see below) at roughly 2" diameter. You'll have to check the other specs to see if they will work (height, etc.). They're also a bit spendy. I'll add: The schematic shows rails are 50V, so I would think anything over a 63V cap would be fine.

https://www.mouser.com/ProductDetail...LmIPKkCQ%3D%3D

I also found these:

https://www.ebay.com/itm/40212262620...cAAOSwcGheVuab

Much cheaper, but you'd have to find something to shim so they fit the clamps, which isn't a huge deal, IMO.

[Enzo]

You can likely find more candidates with conventionally shaped parts rather than trying to fit the retro clamps.

6900uf is not a standard value. Per Dude 6800 is closest, but surely nothing wrong with 8200 or even 10,000.

[The Dude]

I have, at times, just used something to fit around the cap as a shim to be able to use existing clamps. A piece of rubber weather stripping or some such material. Lots of things could work and it leaves you with many more capacitor options.

[Jon Snell]

When I get a picky customer, determined to keep the amplifier as original as possible, I offer the re-stuffing service.
Remove the old contents from the capacitor, being carefull to leave the case clean and unscratched. Place a modern, 6k8uF in your case, (too high a capacitor will stress the mains transformer when being driven at its llimits), and reconnect after potting the new stuffing to stop any vibration.

[J M Fahey]

A whiff of expanding polyurethane foam will make wonders.

Use as little as possible because the d*mn thing keeps expanding and expanding if not constrained and can make a mess.