JJ 20/20/20/40uf cans?

[iknowjohnny]

What do you think about using this cap can instead of seperate F&T 22uf caps for my 3 preamp nodes? Any reasons for one over the other aside from space?

[David Root]

Maybe if you're not using feedback from the OT sec to the PI.

If you are, I would normally want a separate PS node ground on the PI as the OT sec common would normally go to ground at the PI cap ground, not the plate/screen PS node ground.

I'm sure there could be other exceptions too but as a general rule....I like can caps too but you need to be careful with the grounding system.

[mlp-mx6]

I used them in a D-style build with no problem at all.

[bancika]

AX84.com 4-4-0 project, which is a 2w version of the Express uses that cap. Haven't heard any complaints.

[iknowjohnny]

Sounds like a go the. As to your thoughts david, i'm only planning on using the 3 20uf sections for my preamp and a seperate 100uf/100uf can for the outputs. In fact, i wish they had a 20/20/20uf can, as the 40uf section will be going to waste.

This will save me a lot of trouble because i was going to have to try and make space for a board for the PSU caps and didn't have much room. Now a space for the can is all i need. Nice !

[Bruciep07]

From another thread...

Anyone had any experience with CE MFG caps? Says they are made in the US on the old Mallory tooling. They have a 20x20x20 @ 525V and a 40x40x40 @ 525V, I was gonna do another express with Dana's VVR on the front panel, I originally was going to try to squeeze it in there with the normal cap stack but these would make it quite a bit easier...

Those caps are great but like firestorm said, a little pricey. I use a dual 50 JJ cap from tubesandmore.com

CAPACITOR, ELECTROLYTIC, 50/50 µF @ 500 VDC, JJ ELECTRONIC

C-EC50-50-500

Same diameter as LCR. Great for use in Marshall amplifiers.
1-3/8" diameter. x 2" tall.

S-H122 is a good mounting clamp for this can.

RoHS Compliant

and a 40/20/20/20 JJ


CAPACITOR, ELECTROLYTIC, 40/20/20/20 µF @ 500 VDC, JJ ELECTRONIC

C-EC40-20X3-500

2" length x 1 5/8" diameter. Similar to LCR.


RoHS Compliant



You can get both for about the same price as one of the others (if not less) . Just remember to order the mounting clamps to go with them. I have built quite a few amps using these and never had any trouble. They work great.

Here is a couple of pics of an Expres I built with VVR and cap cans

[iknowjohnny]

The C-EC40 appears to be just what i want, but at more than double the price i'll stick with the $15 JJ can and leave the 40uf section unused. Besides, maybe i will need it for something or find the 40UF section works better than 20uf for one of the nodes.

[Bruciep07]

I ordered the JJ's also, other people seem to have had good things to say about them...

[Structo]

I used a couple of those JJ multi-section cap cans before.
They must work good because I never had any hum problems or anything with the amp they were in.

Just stay away from the Chinese crap and you will be fine.

[guitardude57]

Look around, there are 20-20-20 cans out there.........

[Andy Le Blanc]

Cans are very convenient. Its good to have the first filter stage have it's
own ground, at least. Repairing old gear with these can be problematic.
It's so easy to dress the PS resistors strait to the cap lugs, the dress can
end up a mess. The twist locks get fragile so you need to use a metal or
phenolic frame, or make a big hole and use the mounting hardware if do not
have a punch out for the cap type, the ground tabs on the metal type really
should be soldered which is impossible with aluminum chassis. Another
mount option is to mount them side ways in side the chassis ,if there's space,
with nylon cable tie mounts, tie holders or clip mounts, and hefty locking
cable ties. No big holes or extra mount hardware.

[Phil_S]

What Andys says...I used those JJ's as replacements in my Gibson Minuteman (c. 1966). I took the "liberty" of modifying the clamps by carefully bending them for horizontal mount. I say "carefully" because you don't want to flex the metal any more than necessary or it will become weak and unreliable.

It was a shoehorn job, but worked great. I did this when I was quite new at guitar amp stuff and was not comfortable with a soldering iron. This allowed me to clip leads to the old can caps where it met the cap, strip the wire and solder to the lugs on the caps. It came out well. One is 32+32, the other 20+20+20+40. I capped the 40 with heat shrink.

[iknowjohnny]

I've used the JJ 32/32 but never the multi's with more than 2. As to dress, i figured what i would do it put a terminal strip near it so i can run the node resistors to that for stability.
I've decided to build a entire new amp since the chassis is also haggard from too many no longer used holes, plus i wanted new trannys for reasons too longwinded to go into. So today i'm going to order it all. Can't wait to get started ! I'm very interested in doing a very neat build. Therefore if anyone knows of some really good gut shots that illustrate many of the fine fine details on how to neatly dress wires and all that, please link me up.

[Cliff Schecht]

I used some brand new "vintage" Sprague and/or Mallory can caps on a SE design that I wish I had here. Unfortunately the amp is at a friends house and he is down in New Orleans until Thursday. Anywho, I ended up making my own clamps out of some scrap metal and they worked out very well, or at least enough to to hold the caps firmly in place. I used the tabs for ground points and had one tab on each can cap going to a solder lug that was tightly connected to the chassis. It worked great, but that amp has other issues..