Help Finding/Replacing Capacitor Can

[uckabee]

Hi, I'm new here, and new to tube amps. I'm currently working on a 71 Peavey Classic 100 (A-Series). Peavey has been kind enough to provide me with schematics for my amp, but I'm still having difficulty replacing a burned up capacitor can. The cap can that I need to find a replacement for or somehow replace is marked:
30-40 MFD 500 WV
30-40 MFD 500 WV
15-20 MFD 500 WV
15-20 MFD 500 WV

Can someone please explain to me what this means and how I can go about replacing it to make the amp work again?
Thanks,

[martin manning]

It'll be something like this: http://www.tubesandmore.com/products/C-EC4020X2-525 but maybe a different mounting style.

[Leo_Gnardo]

And if that CE goes up in smoke on you (many do) you could replace the can with a nice reliable 50+50 uF 500V can from Ruby, F&T or JJ plus a couple individual caps.

I typically skip the exploding $45 CE cap trick and go straight to the 50+50/500 plus indies. Depending on the amp, I'll use all individuals and leave the original cap in place for looks, but electrically detached from the circuit. Owners of old Fender Champs & Princetons appreciate this.

[uckabee]

So the higher values won't be a problem?

[tribi9]

So the higher values won't be a problem?

It can be sometimes if tube rectified, so when in doubt refer to the data sheet for the rectifier's max capacitance.

[tribi9]

...

[martin manning]

I didn't know those CE multi-section cans were problematic, Leo; thanks for the tip. There might be other options for making up the values too, like three in the can and one single.

[uckabee]

The amp has a tube power section and a solid state pre, if info makes any difference in whether or not that CE would work.

[uckabee]

Sorry for taking so long to get back to this. I've decided to go with individual caps, but I need to know what type of caps to use and how I should go about wiring them. I can't seem to find any good resources on this topic, so any help would be greatly appreciated.

[lord preset]

http://www.tubesandmore.com/products/C-ET47-500-IL
http://www.tubesandmore.com/products/C-ET22-500-IL

You could use these. Both are slightly higher capacitance than the recommended range but should be fine.

If you want to go by the book you can use 16uf and 33uf caps. Axial electrolytics are only available in certain values.

You need to find a spot inside the chassis near the old location of the cans to mount the new caps. You can put them on a board or secure them to the chassis with silicone.

As for connecting them you need to follow the schematic you got from Peavey.

[uckabee]

Thank you so much! The schematic is kinda weird, but I'll give it a shot, and let you all know how it goes

[Cantplay]

The original cap should have symbols on the label for each value. Usually triangle, square, etc.

These correspond to marks by the terminals. The body of the can is ground.

John

[armillary]

uckabee, if you google for images of "replacing electrolytic can caps", you will see some images which will give you ideas of how the new caps might look once you install them. Since they're under the chassis, they don't have to be pretty, they just need to be safe and secure and work. I usually add a pair of terminal strips near the can capacitor and wire the capacitors between them. Sometimes there's not enough room for axial lead caps, so you might consider using radial lead caps. Some advocate putting the new caps in the shell of the old can cap. Any way you do it, replacing a can cap with individual caps is an exercise in creativity and ingenuity, and you might not be proud of how it looks, but it's the most practical thing to do.