Filter failure

[Stevem]

I just had a guys amp on the bench that I recapped a year and a half ago with Atom caps and the amp came in blowing fuses.
Open the dog house and one of the two 20 uf caps was bulged at the end.
I checked it for ESR and it passed with flying colors, I did the same with my cap meter and it passed, yet with that in circuit it blew the fuse every time!

I never had a Atom blue cap fail on me before, no less in such a short time ,

[Firestorm]

I've stopped using the Atoms because of the price (except where I have to fit a cap in an old sleeve for anal retentive purposes). I hate to think they've gone to hell.

[Leo_Gnardo]

The awful truth is right here in TAG's back pages. 6 of em in fact, with lots of photos, what's really inside your formerly favorite caps, plus e-beg bargains.

https://tubeamparchive.com/viewtopic.ph ... sc&start=0

Meters seldom put 'real world' test voltage on caps. OTOH I've seen caps with spuzz obviously leaking out, still working, not heating up. Them, I replace without a second thought.

In one recent case, a 500V cap was mismarked for polarity. Good thing I bring up freshly installed caps with a variac. It wouldn't go past 60V and started to heat up badly. At least it didnt' 'splode. edit: I did slice the offending cap open and it was not one of the "funny business" ones. Stuffed properly as it should be with its innards. So just a labeling misteak.

[Firestorm]

I've been using Gerald Weber's caps lately. No complaints. But I'm one of the few people who likes him.

[Leo_Gnardo]

I've been using Gerald Weber's caps lately. No complaints. But I'm one of the few people who likes him.

I can't imagine Gerald sitting at the kitchen table rolling up caps with a Laredo cigarette machine. Or, maybe I can... In any case he must have someone making them for him, private label ya know. Dan Torres has had his private label orange drop caps for ages now, and there's the "Holy Grail" caps found only in Ceriatone, reported to be Sprague Atoms made in Indonesia without the extra-large barrel & stuffing. Anybody with enough money . . . bottom line is, wonder who makes Gerald's? Got a photo?

Like him or not, if he has something that's above average quality, inquiring minds want to know.

[tony hunt]

I just had a guys amp on the bench that I recapped a year and a half ago with Atom caps and the amp came in blowing fuses.
Open the dog house and one of the two 20 uf caps was bulged at the end.
I checked it for ESR and it passed with flying colors, I did the same with my cap meter and it passed, yet with that in circuit it blew the fuse every time!

I never had a Atom blue cap fail on me before, no less in such a short time ,

Are you going to cut that bulging Atom into two?

[Bob S]

Commiserations - that would piss me off big time.
For the price of Atoms I'd spend an extra few $ for non-polarized, if they'd fit.
I do like F & T's - they ain't cheap but I've had good success.
Don't have an ESR meter (yet) but I always measure with a digi LCR.
Nichicon would be my second choice.
I have used some cheap e-caps & so far no problems. They don't give me the warm fuzzy feeling though.

[Leo_Gnardo]

Commiserations - that would piss me off big time.
For the price of Atoms I'd spend an extra few $ for non-polarized, if they'd fit.
I do like F & T's - they ain't cheap but I've had good success.
Don't have an ESR meter (yet) but I always measure with a digi LCR.
Nichicon would be my second choice.
I have used some cheap e-caps & so far no problems. They don't give me the warm fuzzy feeling though.

Can't say I've ever seen non-polarized iin hi voltage denominations. 100v at most.

F&T cheaper than Atoms last I looked at CE/Antique. And we know about Atoms now don't we . . .

Ruby (NOT Rubycon) from Magic Parts, same as the tubes. I've been using successfully for years. Someone mentioned they're available thru Parts Express but they mark up the price. Get an account at Magic, buy them by the 50-pak, save a ton of loot. I don't know who makes 'em but they do work well for me, and you can too.

[pdf64]

Leo, I think Bob may have been refering to film caps, eg http://www.audiocap.co.uk/20uf-630v-amp ... -303-p.asp
I've also heard mention of the use of the use of caps intended for phase shift on motors, in amp B+ supplies.
I think RG Keen may have endorsed the idea?

[Bob S]

Yup - Colossal built an amp using them that really had me Jonesin...
Sposed to last forever - expensive boogers though.
Some yellow Atoms are NP too.

[Leo_Gnardo]

Leo, I think Bob may have been refering to film caps, eg http://www.audiocap.co.uk/20uf-630v-amp ... -303-p.asp
I've also heard mention of the use of the use of caps intended for phase shift on motors, in amp B+ supplies.
I think RG Keen may have endorsed the idea?

Well dog my cats, yes I think films are terrific. I've used some 630V 22 uF Solen caps to replace 20 or 30 uF 600V "dynamite sticks" in B-15 and similar amps. They typically take up more space but that's the price of reliablity. Amp manufacturer Carr has been using film caps in their power supplies for quite a while now, I'm guessing 15 years at least.

Someone brought to my attention, now Mouser carries Panasonic hi voltage vilm caps in rectangular packaging for those who want "maximum functional density." How to hold 'em in place? Might have to fiddle with some mini brackets.

[gui_tarzan]

After reading all of the horror stories about Atom caps I only use F&T or TAD in customer repairs for filter caps.

[tony hunt]

I have seen the photos with the cheap electrolytic hiding inside the Atom case.
If you think about the time it would take to do that, it points to very cheap Far-East labour or a complete hoax.

I got curious today as to what goes on inside the can:
47uF F+T
16uF Sprague Atom
22uF RIFA PEG124

I have Sprague Atoms in a '58 Deluxe and they run fine.
Could it be that it depends on where you source from?

[Stevem]

I don't think so, with the level of QC its pot luck I guess now even with the Atoms!
Stuff just anit the same any more! I threw together a small single ended amp of kicks some months ago and I used a multi can cap I took out of a 1972 Hiwatt amp and I ve been playing it near every night since I built it with no power supply issues!

I have 50 uf of filtering on 6ca4 recto and its been fine!

[Leo_Gnardo]

I have seen the photos with the cheap electrolytic hiding inside the Atom case.
If you think about the time it would take to do that, it points to very cheap Far-East labour or a complete hoax.

I got curious today as to what goes on inside the can:
47uF F+T
16uF Sprague Atom
22uF RIFA PEG124

I have Sprague Atoms in a '58 Deluxe and they run fine.
Could it be that it depends on where you source from?

Thanks for up-to-date photo of the insides of these caps, tony hunt.

It doesn't have so much to do with where as when. At some point the innards of the Atom "shrunk" but Vishay/Sprague, recognizing a market, continued to use the same package size and cover. Granted, they are less able to dissipate heat by not being snug up to the package surface, a detriment. So much for Atoms "Mo-joooooooooooo!"

AFAIK Vishay is now the owner of Sprague. It's possible this jiggery-pokery started at the time of Vishay's takeover.

Consider also the Holy Grail filter caps found in Ceria amps & kits. They are supposedly the same cap as Atoms, but packaged in form-fit jackets, very snazzy. Wouldn't it be nice to have the same item available at our parts distributors, at a reasonable price. I'm sure it doesn't cost any more to make and ship them than any other competent capacitor.