electrolytic cap suggestions for smps and tube

first of all pardon me if this is in the wrong subforums as I wasn't completely sure where to put it.

I'm building an smps that I tested on the bench so to speak of and it works so now i'm putting it together with attention to detail , he question that i struggle with is output ripple previously used 4x470uF capacitors and there was still some small ripple in the output , the caps were also old and untested.

i ask the question because i would love to hear some advice from you guys in terms of which caps are better and also optimal for the price.
i have enough space to put about 4x1000uF/200v caps on the board , together i have two transformers so for each output 4 electrolytics a total of 8 on the board.I went through catalogues but there are so many from which to choose that i'm a bit lost.
I do know the main factors to look for are ripple current rating, temperature maximum rating and lifetime rating , also ESR.
so maybe you have some good caps in mind that you have been using yourselves and could recommend,


the other question is about a tube amp that i recently got , the amp has been long unused and the caps themselves are old , maybe you can give me some suggestions which ones would be better in that area, apart from that it's a nice sounding tube amp would love to keep it that way or even a bit better if possible by new parts.
the caps are rated 300v/200uF each.also there are some low capacitance films on the channel boards , what are commonly good brands for those , WIMA?

thanks in advance
 

Mooly

Administrator
Paid Member
2007-09-15 8:14 am
:cop:
I've moved this to 'Power Supplies' as it seemed more appropriate.

:)

SMPS... so that will be running at high frequency which normally means that the caps are correspondingly smaller in value. Low E.S.R. (equivalent series resistance) caps are normally chosen for this possible used in conjunction with series inductive elements in the supplies. If you have low frequency ripple in the SMPS output then that perhaps points to a design issue.

I would probably stick with the same (or similar) values for the tube amp as was originally fitted. Going to large can be a problem for tube rectifiers (assuming it uses them).

Yes, Wima are a good brand. Others are EPCOS, Vishay and LCR.
 
well the ripple is not low frequency it's the same switching frequency for the smps , just harmonics along the way.
i use IGBT's and the frequency is about 50khz.

basically im looking at some nichinons or panasonic or cornell dubilier , i really dont know there are many maybe the brand is not so important rather the price and the specs.