Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: joesatch on August 18, 2024, 08:19:24 am

Title: cap can question
Post by: joesatch on August 18, 2024, 08:19:24 am
can a 50 + 50uf cap can have the two sections wired in series? i'm guessing no since they share the same ground.  So when folks tie the two + leads together they are paralleling the two sections to get double capacitance with the same voltage?
Title: Re: cap can question
Post by: shooter on August 18, 2024, 09:33:33 am
No is correct


"caps in parallel are like resistors in series"
so double the capacitance (think cap plate surface area)


Needs a double-check but think; "voltage is halved"
Title: Re: cap can question
Post by: dwinstonwood on August 18, 2024, 10:05:10 am
oops, never mind! deleted.
Title: Re: cap can question
Post by: joesatch on August 18, 2024, 10:44:49 am
well imma cut open this cap can in the hopes there are two smaller caps inside i can pull out and wire in series.
Title: Re: cap can question
Post by: shooter on August 18, 2024, 12:00:33 pm
what's your end-game?  Higher voltage rating?

Title: Re: cap can question
Post by: Carlsoti on August 18, 2024, 01:16:47 pm
Vintage can caps are layers of various materials rolled into a cylinder, impregnated with electrolytic material, then stuffed in a can and sealed up, not just a couple smaller caps stuffed in the can. Some newer vintage-style replacements might be that way, though.
Title: Re: cap can question
Post by: stratomaster on August 18, 2024, 01:41:40 pm
what's your end-game?  Higher voltage rating?

Just add a 2nd cap in series. A 100-220μF at 160v is relatively small. Add appropriate totem pole resistors to ensure voltage rating isn't exceeded.  Take a look at the reservoir cap on the Deluxe Reverb reissue schematic.

No need to cut a cap open.
Title: Re: cap can question
Post by: kagliostro on August 18, 2024, 01:45:22 pm
https://www.nmr.mgh.harvard.edu/~reese/electrolytics/ (https://www.nmr.mgh.harvard.edu/~reese/electrolytics/)

https://www.instructables.com/Tube-Radio-Capacitor-Can-Replacement/ (https://www.instructables.com/Tube-Radio-Capacitor-Can-Replacement/)

Franco