Who knows their electrolytic capicitors?

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dragonworks

dragonworks

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HELP!!!!

I have to make a choice between capcitor styles, the price differecne is like eighteen bucks apiece. I asked at the site but don't trust their answer.
What I need to replace is a can cap, oil i think, anyways, four sections
20/20/10/10 at 450V

I am not sure of the difference between the caps below, they are different style, both electorlytics, can I use either?

this is the link to the site, I think you will have to search the part numbers I give or search caps/electrolytic/multi

http://tubesandmore.com/

here is the number to search for this cap C-EC20X4-475
$33.00
description
CAPACITOR, ELECTROLYTIC, 20/20/20/20 µF @ 475 VDC
Made in the USA, to the same specs as the Original Mallory, on Mallory's original machinery.
* 4 sections - all 20 µF @ 475 VDC
* -10%, +50% tolerance
* 85° temperature rating
* 1-3/8" diameter x 2" tall

here is the other one, it is $14.00
Search this number C-EC40-20X3-500
description
CAPACITOR, ELECTROLYTIC, 40/20/20/20 µF @ 500 VDC, JJ ELECTRONIC
2" length x 1 5/8" diameter. Similar to LCR.
 
I think that if this is for power supply ripple smoothing, either one is OK (they are both electrolytics), assuming the physical mounting and leads are compatible with what you are replacing. They are both within spec, voltage-wise, and the extra capacitance is fine if used in a PS, - though one is made in USA and the other - ???
 
They don't show the leads. Or the bottom of the caps. As for mounting, I am a machinist and can adapt, there is room for either one.

I emailed the site and was told they thought the cheaper one had "to much capacitance" (in the first stage 40 as opposed to 20 in the original)for the application. I have been under the impression that when replacing caps it is ok to go higher with the farad and voltage rating?

Yes, this is for a power suppy.
 
I doubt that going from 20 to 40uf is going to make a whit of difference in this application, any more than going from 10 to 20uf for the other values :). Do you have a link to the schematic?
 
All I have is a sams photofact and no scanner. It is in the power supply of a Masco amp. No preamp. 2 rec tubes, two 6l6, mono, two other tubes, forget the number.
I have the part number for the existing can, it is an aerovox. It has the values and the icons on the side but as of yet I don't know how to identify them to the leads on the bottom. I don't see the icons anywhere near the leads. I don't see anything there. I might have to use the schematic to figure which is which.

What do you need to know from the schematic, maybe I can tell you.
 
Looks like your power supply is this one, or very similar. It shouldn't matter much which capacitor lead goes where, as long as you can ID the common (ground) lead, which is probably connected to the can. I'm surprised the icons aren't marked on the bottom next to the tabs.
http://www.schematicheaven.com/bargainbin/masco_mu17.pdf

This PS has a leg going to the preamp, which if your amp doesn't have, maybe it's not using this leg of the circuit and you can disregard the 40uf connection if you use this cap:
http://www.thetubestore.com/ca-jj-40uf-500v.html

You should trace out the circuit on the chassis and compare it to the schematic to make sure.
 
that is pretty much the PS. My amp is a 20 watt concert master desigined for hi fi aps and had a seperate preamp that came with it but it is basically the same power supply.
All the legs are used. I can ID the common through the schematic, all the wires are color coded and in the sams photofact is has all the info. You are probably familiar with the sams photofacts. It would just make it easier if they had identified the legs.

The site you referred to me charges 4 more dollars for the same cap at the site i referred at the beginning of the thread?
 
Yeah, that's the same cap. I just used it because the picture was big. :)

Good luck.
 
The extra capacitance could be an issue due to surge current when the unit is powered up. You can't just say it is ok. You could blow a fuse or smoke a rectifier. It all depends on the rest of the component ratings in the power supply.
 
could you go into detail further. I don't have much choice, I cannot fine a replacement cap of the same value.
 
I've been reworking some Silvertone amps lately, which have a multisection "can". Luckily with these, you have room to install three individual caps with the same value(higher voltage rating is ok). Is this an option, space-wise?
 
0018G said:
I've been reworking some Silvertone amps lately, which have a multisection "can". Luckily with these, you have room to install three individual caps with the same value(higher voltage rating is ok). Is this an option, space-wise?
Click to expand...

I could make anything fit, when all is said and done I have to make the enclosure, but for aesthetics(SP)and ease I would rather use a can.
 
Henry Mars said:
The extra capacitance could be an issue due to surge current when the unit is powered up. You can't just say it is ok. You could blow a fuse or smoke a rectifier. It all depends on the rest of the component ratings in the power supply.
Click to expand...
It won't change the maximum value of the current (this is controlled by the resistors) but would change its duration (longer to charge up a larger capacitor.) The last leg of the PS circuit using a 20uf cap draws an initial (surge) current of about 8ma - this falls to about 3 ma in 0.9 seconds (ignoring the other branches of the circuit which would significantly decrease this time.) If you substitute a 40uf cap, the fall from 8ma to 3ma would take twice as long - 1.8 sec. So the question is, could the other circuit components dissipate this (minimally) increased power requirement? I don't know, but I bet they would. :)
 
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