Can caps?

[drewl]

and speaking of the Princeton Reverb,
What are you guys using for the multi-section can caps?

Are CE the only game in town?

It has a CE in that went bad.
Pulled it apart, and the tab connections into the dialectric corroded and broke off.

Tried cleaning them to see if I could solder them back, but the metal is all funky.

[xtian]

Are you committed to using a can? I prefer to leave the can in place, but bend the tabs out of the way, and install new, radial caps in its place. Easy and inexpensive!

[drewl]

If it was my amp, I'd do in a heartbeat.

Customers old Fender, putting it back to stock.

[Justin Thomas]

I wrote a whole rant post about this a while back. I've had too many CE cans go bad on me. Maybe I'm just cooking them cuz I'm constantly tweaking, but when it comes to a $45 part I get tired of throwing them away. I've used the JJ cans with success, though they don't fit the holes. I'm with xtian - I'm switching to compact radials. Even if I have to series a couple. They're so tiny any more! And even axials are much smaller.

I think with a vintage Princeton Reverb I'd stick with a CE if I knew it was the only problem, but more likely I'd stuff the can with modern replacements. And there's plenty of room in the chassis to finagle stuff.

Justin

[Leo_Gnardo]

Are you committed to using a can? I prefer to leave the can in place, but bend the tabs out of the way, and install new, radial caps in its place. Easy and inexpensive!

That's what I do ^^^.

For those seeking alternative can caps, that is, non-CE, have a look at Hayseed Hamfest. They seem to cater to ham radio people but no matter, they have can caps we may be able to use in amps. I haven't used any yet nor have I seen any independent reviews. Their prices seem to be generally a little cheaper than CE.

First you'll see an "in memoriam" page. Scroll down to find caps & cap kits.

https://hayseedhamfest.com/

[Justin Thomas]

I just wish they'd show the dimensions... Since I don't have any vintage hifis laying around...

Jusrin

[Mick Bailey]

With quite a few can caps they can be re-stuffed. I do this quite often and it works out pretty well. When the terminals are bad I make up a new end plate and have some replacement terminals that rivet over like an eyelet but have a solder tag. I use a lathe to open the can and re-crimp it but its straightforward to do this manually.

[Bloomfield]

Mick, I'm curious about your lathe technique for opening and closing the cans. Do you use a toolpost with two posts to lever against, as with sheet-metal spinning?

[drewl]

I pried out the base plate and saw where the four connections had corroded and broke.

Don't know what kind of metal they are as you can't solder anything to them.

[g1]

Maybe aluminum? Do you have any aluminum solder?

[The Dude]

Do not the same lugs you solder to on the outside go through the base plate to the inside? I'm thinking the inside of the contacts are just dirty or coated with something. Have you tried giving them a good scraping/cleaning? Maybe also some extra flux. I can't imagine the contacts would be some different material inside the cap.

[g1]

How many sections? Justradios has RG and JJ (duals). Dimensions listed on this page: https://www.justradios.com/DUALsection.html

[dmartn149]

I just recently (last week) re-stuffed a can cap. All the internal connections were aluminum. I used a dremel to cut the can close to the base, unwound all the paper and foil and snipped the aluminum tabs off. The 4 caps I used were a good tight fit inside the can, so I inserted them in with all the neg. leads to the center. I bundled and soldered them together then drilled 5 holes in the base plate, fed the leads through and soldered the pos. leads to their lugs on the bottom. It's working perfectly so far. Pretty easy too

[drewl]

Do not the same lugs you solder to on the outside go through the base plate to the inside? I'm thinking the inside of the contacts are just dirty or coated with something. Have you tried giving them a good scraping/cleaning? Maybe also some extra flux. I can't imagine the contacts would be some different material inside the cap.

No, five thin aluminum (?) Strips from inside the dialectric material and wrap go through a rubber insulated, the phenolic base and have the normal metal contacts crimped onto them with the ground strip crimped onto the bottom cap ring.

I should take pix so we all can see the construction.

[Mick Bailey]

Mick, I'm curious about your lathe technique for opening and closing the cans. Do you use a toolpost with two posts to lever against, as with sheet-metal spinning?

Yes, just the same arrangement but scaled down for the caps. I run at slower speed and protect the can from the chuck jaws with a single wrap of masking tape. When opening up the rolled edge use a hose clamp ('Jubilee clip') if necessary to limit any flaring. Using a clamp is a good idea if unrolling them manually as it ensures the edge stays even. If there's a sign of the can work-hardening I anneal the edge after removing the contents. I use the old trick of rubbing soap on alloy and only heating it until the soap begins to turn brown.

Sometimes If there's enough depth where the end cap is fitted I'll slice through the edge and not unroll it. Some caps have a number of seals, as well as the end cap and other parts. When restuffing you don't need to seal the contents from leakage so when reassembling without gaskets there can be enough metal left to turn back over.

See post #9 here for a picture of how the lip of the can ends up;

https://music-electronics-forum.com/...ht=re-stuffing