Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: ajeffcote on February 19, 2012, 08:44:35 am

Title: Inside an Atom
Post by: ajeffcote on February 19, 2012, 08:44:35 am
(http://i837.photobucket.com/albums/zz300/ajeffcote/Inside%20an%20Atom/InsideanAtom013.jpg)
(http://i837.photobucket.com/albums/zz300/ajeffcote/Inside%20an%20Atom/InsideanAtom008.jpg)
I have too much time on my hands, huh? I have heard rumors that these were really just cans with labels concealing a small cheap cap. Myth de-bunked.
Title: Re: Inside an Atom
Post by: Colas LeGrippa on February 19, 2012, 08:53:13 am
where are the neutrons and protons ?
Title: Re: Inside an Atom
Post by: Willabe on February 19, 2012, 10:23:53 am
I cut an Atom open 20uf/500v and inside the can the cap itself was a 1/3 the size of the can.


                      Brad    
Title: Re: Inside an Atom
Post by: ajeffcote on February 19, 2012, 11:01:05 am
I cut an Atom open 20uf/500v and inside the can the cap itself was a 1/3 the size of the can.


                      Brad    
Very interesting. These are maybe 5 or 6 years old.
Title: Re: Inside an Atom
Post by: HotBluePlates on February 19, 2012, 03:52:42 pm
Maybe this is Willabe's old picture... I don't remember who posted it, but I saved it when posted on this forum some time back.
Title: Re: Inside an Atom
Post by: Willabe on February 19, 2012, 06:05:08 pm
Sluckey posted it.

I cut one open a few days later, looked just like Sluckeys picture.


                          Brad     :icon_biggrin:
Title: Re: Inside an Atom
Post by: John on February 19, 2012, 08:16:06 pm
Well next time you feel like cutting open a cap, just send it to me (whole) instead!  :laugh:
Title: Re: Inside an Atom
Post by: SoundmasterG on February 25, 2012, 12:45:38 am
I've got some 20uf 600V Atoms from around 1995 that I reformed. They seem to work ok but I can't find something to use them in....I won't use them in a customer's amp! Anyway, I could probably cut one of them open and see if they are the small cap inside or not....I won't buy Atoms anymore myself....too overpriced...

Greg
Title: Re: Inside an Atom
Post by: HotBluePlates on February 25, 2012, 12:56:13 am
An easier test is to thump the side of the cap with your finger.

Something that's solid all the way through has an obvious "solid" feel/sound. Just a dull thunk when you thump it.

Atoms always have a weird hollow "boing" to them. That's how I equate the pictures above to my experience, without cutting open a cap. That, and I save myself the mess.
Title: Re: Inside an Atom
Post by: EL34 on February 25, 2012, 06:19:32 am
Just look at the size of an Illinois cap
That is probably what is inside the sprague.

My brain goes the logic route on things like this
Does Illinois have some top secret material that allows the same capacitance in a smaller package?

Why would spragues need to be so much larger?
Maybe Sprague uses old rubber floor mats from the junk yard to make the insulating material thicker?
Title: Re: Inside an Atom
Post by: FYL on February 25, 2012, 06:55:49 am
Quote
Just look at the size of an Illinois cap
That is probably what is inside the sprague.

AFAICT Vishay/Sprague elcos are still made by United Chemi-Con. Small windings, large old-style case, thermal nightmare.

Quote
Does Illinois have some top secret material that allows the same capacitance in a smaller package?

IC and others use modern materials and technologies, allowing them to pack mo' capacitance in small packages.

Quote
Why would spragues need to be so much larger?

Vintage appeal.
Title: Re: Inside an Atom
Post by: bigsbybender on February 26, 2012, 04:55:16 am
It's probably been said here before...

Spragues are made for replacement purposes.  Look at the big warehouse sellers, they state that the Atoms are for replacement and not new build.... The size of the can is merely because some equipment (likely military and industrial) would call for a cap of that value AND that physical size... When that equipment was built in 1966, that was the smallest size for a cap of that value..... but legacy contracts call for a 3.25" x .80" capacitor in some applications. The Atom fits that need.
Title: Re: Inside an Atom
Post by: EL34 on February 26, 2012, 02:40:18 pm
Yet, you will find the guys that think that sprague must be better because it is larger.

Same guys probably believe an amp is better because it has knobs that go to 11 or 12

Title: Re: Inside an Atom
Post by: John on February 26, 2012, 03:28:11 pm
Well, 11 is obviously louder 10!
Title: Re: Inside an Atom
Post by: cbass on February 26, 2012, 05:22:21 pm
Yet, you will find the guys that think that sprague must be better because it is larger.

Same guys probably believe an amp is better because it has knobs that go to 11 or 12




Its not only how far the knobs go.Its the number of them.The more the better.
Now if you have an amp with 20 knobs that go to 12 .Then it must sound better than an amp with just a few knobs.Add some big ass caps in there and you get the best sounding amp of all time.
Title: Re: Inside an Atom
Post by: mresistor on March 01, 2012, 04:44:23 pm
the Illinois caps seem to weigh less than others..... and this disturbs me some.... where have they scrimped...

the OPs pic really doesn't seem to prove anything....


Title: Re: Inside an Atom
Post by: Willabe on March 01, 2012, 05:09:02 pm
the Illinois caps seem to weigh less than others.....

Caps used to be wound with 2 separate pieces, 1 a conductor and the other a non-conductor. Like film and foil caps. Now they have gone to spraying the film (non-conductor) with a metal (the conductor), metalized film.

Orange drops are film and foil, which accounts for their larger size compared to a smaller sized metalized film cap of the same capacitance and voltage.

So less material over all = less weight and size.



                    Brad