Results 1 to 23 of 23

Thread: Ever wonder about the Sprague Atom controversy?

  1. #1
    Supporting Member Randall's Avatar
    Join Date
    Jan 2013
    Location
    Cape Coral, FL
    Posts
    2,396
    Thumbs Up/Down
    Received: 529/0
    Given: 95/0
    Rep Power
    9

    Ever wonder about the Sprague Atom controversy?

    I had the occasion to replace a blue Atom cap, and have always wanted to cut one open to see what they are made of. I guess we've all seen or heard the claims that some are fakes with little chinese caps stuffed inside. Well, here is what this one looks like.

    Click image for larger version. 

Name:	001.JPG 
Views:	128 
Size:	461.4 KB 
ID:	53646Click image for larger version. 

Name:	002.JPG 
Views:	146 
Size:	568.4 KB 
ID:	53647Click image for larger version. 

Name:	003.JPG 
Views:	149 
Size:	553.9 KB 
ID:	53648Click image for larger version. 

Name:	004.JPG 
Views:	136 
Size:	555.2 KB 
ID:	53649

    0 Not allowed! Not allowed!
    It's weird, because it WAS working fine.....

  2. #2
    Master Destroyer nosaj's Avatar
    Join Date
    Sep 2011
    Location
    Pace, FL
    Posts
    3,213
    Thumbs Up/Down
    Received: 1,093/102
    Given: 146/35
    Rep Power
    12
    Quote Originally Posted by Randall View Post
    I had the occasion to replace a blue Atom cap, and have always wanted to cut one open to see what they are made of. I guess we've all seen or heard the claims that some are fakes with little chinese caps stuffed inside. Well, here is what this one looks like.

    Click image for larger version. 

Name:	001.JPG 
Views:	128 
Size:	461.4 KB 
ID:	53646Click image for larger version. 

Name:	002.JPG 
Views:	146 
Size:	568.4 KB 
ID:	53647Click image for larger version. 

Name:	003.JPG 
Views:	149 
Size:	553.9 KB 
ID:	53648Click image for larger version. 

Name:	004.JPG 
Views:	136 
Size:	555.2 KB 
ID:	53649
    Is the Date code 7/92? Did I read that right? If so probably well before the fakery.

    nosaj

    1 Not allowed! Not allowed!
    Binkie McFartnuggets‏:If we really wanted to know the meaning of life we would have fed Stephen Hawking shrooms a long time ago.

  3. #3
    Supporting Member nevetslab's Avatar
    Join Date
    Apr 2010
    Location
    Burbank, CA
    Posts
    1,793
    Thumbs Up/Down
    Received: 647/1
    Given: 1,478/1
    Rep Power
    11
    Quote Originally Posted by nosaj View Post
    Is the Date code 7/92? Did I read that right? If so probably well before the fakery.

    nosaj
    7th week of 1992.

    0 Not allowed! Not allowed!
    Logic is an organized way of going wrong with confidence

  4. #4
    Old Timer J M Fahey's Avatar
    Join Date
    Oct 2007
    Location
    Buenos Aires, Argentina
    Posts
    11,753
    Thumbs Up/Down
    Received: 1,881/23
    Given: 1,463/35
    Rep Power
    27
    It´s probably a semi-fakery ...made by the original maker: a regular modern smaller electrolytic (of reasonably good quality if it worked for 15 years) but packed in a way too large MOJO-full blue case and sold at 2X or 3X the regular price.
    Was it floating inside or there was some kind of structure to avoid it vibrating to death?

    2 Not allowed! Not allowed!
    Juan Manuel Fahey

  5. #5
    Master Destroyer nosaj's Avatar
    Join Date
    Sep 2011
    Location
    Pace, FL
    Posts
    3,213
    Thumbs Up/Down
    Received: 1,093/102
    Given: 146/35
    Rep Power
    12
    Quote Originally Posted by J M Fahey View Post
    It´s probably a semi-fakery ...made by the original maker: a regular modern smaller electrolytic (of reasonably good quality if it worked for 15 years) but packed in a way too large MOJO-full blue case and sold at 2X or 3X the regular price.
    Was it floating inside or there was some kind of structure to avoid it vibrating to death?
    I think what your seeing is the plastic wrap was cut an then expanded out some.. Looks legit to me.

    nosaj

    1 Not allowed! Not allowed!
    Binkie McFartnuggets‏:If we really wanted to know the meaning of life we would have fed Stephen Hawking shrooms a long time ago.

  6. #6
    Bent Member Chuck H's Avatar
    Join Date
    May 2007
    Location
    pacific north west
    Posts
    15,340
    Thumbs Up/Down
    Received: 2,318/4
    Given: 2,699/0
    Rep Power
    30
    Pretty sure Juan was talking about the size of the actual capacitor as it relates to the can. I've cut open a number of them over the course of the last decade (some old, some newer) and they always look like Randall's photos.

    0 Not allowed! Not allowed!
    "Never bet your life on somebody else doing their job." SoulFetish's good friend

    "Now get off my lawn with your silicooties and boom-chucka speakers and computers masquerading as amplifiers" Justin Thomas

    "Being born on third base and thinking that you must have hit a triple is pure delusion!" Steve A

    "Back to the amp. It makes horrible sounds when I play my guitar thru it... because I suck at playing guitar." Mike6158

  7. #7
    Supporting Member The Dude's Avatar
    Join Date
    May 2010
    Location
    Sioux Falls, SD
    Posts
    6,325
    Thumbs Up/Down
    Received: 1,220/1
    Given: 950/1
    Rep Power
    16
    I don't think it matters what's inside. Everybody knows the tone and mojo comes from the pretty blue plastic shrink wrap on the outside.

    1 Not allowed! Not allowed!
    “Yeah, well, you know, that’s just, like, your opinion, man.”

  8. #8
    Old Timer
    Join Date
    May 2006
    Location
    Chill-Ville, VA
    Posts
    3,171
    Thumbs Up/Down
    Received: 676/6
    Given: 1,304/9
    Rep Power
    18
    I like F&T. Same quality, great price, GREAT presentstion, half the frickin' size. So if I wanna upgrade my Fenders, they'll fit in the blasted doghouse... Unlike Sprague!

    Jusrin

    5 Not allowed! Not allowed!
    "Wow it's red! That doesn't look like the standard Marshall red. It's more like hooker lipstick/clown nose/poodle pecker red." - Chuck H. -
    "Of course that means playing **LOUD** , best but useless solution to modern sissy snowflake players." - J.M. Fahey -
    "All I ever managed to do with that amp was... kill small rodents within a 50 yard radius of my practice building." - Tone Meister -

  9. #9
    Senior Member
    Join Date
    Jan 2014
    Location
    Chiraq
    Posts
    1,002
    Thumbs Up/Down
    Received: 213/5
    Given: 249/1
    Rep Power
    7
    Click image for larger version. 

Name:	IMG_2579.JPG 
Views:	49 
Size:	1.47 MB 
ID:	53652
    Click image for larger version. 

Name:	IMG_2580.JPG 
Views:	48 
Size:	1.28 MB 
ID:	53653

    Here's one from United Chemicon. Not as much extra space inside the cap. So as you can see it has FAR less mojo than the sprague.

    At least on the plus side it's only about $5-6 for a long life cap rated at 15,000 hours lifetime at +85°C with the rated ripple current applied.

    I cut this one open because once in the past I tightened the capacitor clamp too much and I made a dent in the casing. I worried it might have damaged the cap. Guess they add a little safety margin in if you do a klunky move like that ??

    3 Not allowed! Not allowed!

  10. #10
    Bent Member Chuck H's Avatar
    Join Date
    May 2007
    Location
    pacific north west
    Posts
    15,340
    Thumbs Up/Down
    Received: 2,318/4
    Given: 2,699/0
    Rep Power
    30
    FWIW I stopped using Atom caps, or any axial cap, several years ago. I've selected a brand and model of radial cap that is more forthcoming in it's specs and a lot less expensive (Atom's are up to about $15+ for 100uf @ 450V!!!). And I did this because I had a couple of builds that I used "fresh" Atom caps on that exhibited symptoms of failing filter caps. I bought the new Atom's from Mouser and I don't expect they grabbed some old, dusty crap they found under the shelf, but I can't know. But that was the last straw. Atom's have very vague spec sheets and a very high price. Having two amps requiring service to those parts as new was the deciding factor and I switched. So... Why go to radial instead of just a different axial product? Simple. All modern products have changed to radial lead board layouts so the greatest selection, options and price break was in that category. Axial caps are the odd man out now with fewer options and, very often, less defined spec sheets. The most you can often hope for with axial options is what gets said about them on "tube amp" forums. Bah! There are ways around the axial lead implementation even on older amps and the options and savings in radial offerings was just too great to ignore.

    JM2C

    2 Not allowed! Not allowed!
    "Never bet your life on somebody else doing their job." SoulFetish's good friend

    "Now get off my lawn with your silicooties and boom-chucka speakers and computers masquerading as amplifiers" Justin Thomas

    "Being born on third base and thinking that you must have hit a triple is pure delusion!" Steve A

    "Back to the amp. It makes horrible sounds when I play my guitar thru it... because I suck at playing guitar." Mike6158

  11. #11
    Old Timer
    Join Date
    May 2006
    Location
    Chill-Ville, VA
    Posts
    3,171
    Thumbs Up/Down
    Received: 676/6
    Given: 1,304/9
    Rep Power
    18
    I still use axial caps cuz I build so few amps, but that design you posted a few years ago about how to work with radials was flat-out badass. I doenloadedit. Then between 3 gadgets lost it. But friggin' brilliant.

    Justin

    2 Not allowed! Not allowed!
    "Wow it's red! That doesn't look like the standard Marshall red. It's more like hooker lipstick/clown nose/poodle pecker red." - Chuck H. -
    "Of course that means playing **LOUD** , best but useless solution to modern sissy snowflake players." - J.M. Fahey -
    "All I ever managed to do with that amp was... kill small rodents within a 50 yard radius of my practice building." - Tone Meister -

  12. #12
    Bent Member Chuck H's Avatar
    Join Date
    May 2007
    Location
    pacific north west
    Posts
    15,340
    Thumbs Up/Down
    Received: 2,318/4
    Given: 2,699/0
    Rep Power
    30
    Quote Originally Posted by Justin Thomas View Post
    I still use axial caps cuz I build so few amps, but that design you posted a few years ago about how to work with radials was flat-out badass. I doenloadedit. Then between 3 gadgets lost it. But friggin' brilliant.

    Justin
    Why, thank you! I don't think it should go unmentioned though that I probably wasn't the first to come up with the lay down and zip tie method. I know for sure I'm not the only one anyway because at about the same time there were other members here already doing it just about the same way. An added benefit I've found is that it lends itself to locating filters with their respective gain stages and it can also be a space saver in the linear direction because you can usually have two capacitors on the same board width that would typically just have one cap in the middle. Maybe it takes the thread a little off topic, but I'll see if I can locate the thread and link it in an edit.

    EDIT: Well I'm not sure I found the thread in question, but here's some good info on using radial caps in place of axials and there IS a diagram of the method I've used for new builds.
    https://music-electronics-forum.com/...t=28261&page=2

    3 Not allowed! Not allowed!
    Last edited by Chuck H; 05-18-2019 at 03:43 PM.
    "Never bet your life on somebody else doing their job." SoulFetish's good friend

    "Now get off my lawn with your silicooties and boom-chucka speakers and computers masquerading as amplifiers" Justin Thomas

    "Being born on third base and thinking that you must have hit a triple is pure delusion!" Steve A

    "Back to the amp. It makes horrible sounds when I play my guitar thru it... because I suck at playing guitar." Mike6158

  13. #13
    Senior Member SoulFetish's Avatar
    Join Date
    Jan 2016
    Location
    Massachusetts
    Posts
    1,206
    Thumbs Up/Down
    Received: 409/1
    Given: 346/0
    Rep Power
    6
    you guys and your electrolytic caps..

    This large housing used in atoms is annoying. I can only assume they do it is for the perception of ruggedness/quality of the brand; if you consider how consumers place value on components in audio electronics, I guess I can understand it.
    What I can't understand at all, is how any self respecting modern manufacturer sells an electrolytic with a temp rating of 65˚!!!
    I would never spec a capacitor in an amplifier build with a capacitor temperature rating like that, particularly in a tube amp.
    having said that, I really never see them fail. My observation working on amps that use atom filter caps is that they may actually be a pretty reliable cap.
    Personally, I use MKP caps unless there are constraints that make it prohibitive. But I think they are worth designing around. In our service shop however, we've been regularly using F&Ts in the HT power supply, and Vishay's for bypass caps for replacement parts with great success.

    1 Not allowed! Not allowed!
    If I have a 50% chance of guessing the right answer, I guess wrong 80% of the time.

  14. #14
    Lifetime Member Enzo's Avatar
    Join Date
    May 2006
    Location
    Lansing, Michigan, USA
    Posts
    32,030
    Thumbs Up/Down
    Received: 1,821/7
    Given: 0/0
    Rep Power
    55
    They do it because there is a market for old school parts. Atoms were used on older gear. They had long bodies and longer leads. Just what you need in point to point stuff. When I rebuild old jukeboxes, the paper caps had long bodies and long leads. I use nice radial 0.047/630v caps in them, one inch leads, and I have to clip the old wires off at the old cap body, then splice the new cap to the old wires. Looks crappy.

    1 Not allowed! Not allowed!
    Education is what you're left with after you have forgotten what you have learned.

  15. #15
    Bent Member Chuck H's Avatar
    Join Date
    May 2007
    Location
    pacific north west
    Posts
    15,340
    Thumbs Up/Down
    Received: 2,318/4
    Given: 2,699/0
    Rep Power
    30
    Quote Originally Posted by SoulFetish View Post
    I really never see them fail. My observation working on amps that use atom filter caps is that they may actually be a pretty reliable cap.
    Same here. And that's why I used them for years. They were a recognized staple and people generally liked seeing them in the amps. As long as I wasn't having a problem I just ponied up the extra cash. But then I started having problems with new Atoms. Not "unused sitting in the drawer for a few years", but ordered new specifically for the project. I deal with enough of that trying to get good tubes that'll hold up. I sure don't need to start doing the same with components. I've been using Nichicon PW's for the last three amps and also as replacements for re-caps. No problems yet and they take a smaller bite out of the budget.

    0 Not allowed! Not allowed!
    "Never bet your life on somebody else doing their job." SoulFetish's good friend

    "Now get off my lawn with your silicooties and boom-chucka speakers and computers masquerading as amplifiers" Justin Thomas

    "Being born on third base and thinking that you must have hit a triple is pure delusion!" Steve A

    "Back to the amp. It makes horrible sounds when I play my guitar thru it... because I suck at playing guitar." Mike6158

  16. #16
    Bent Member Chuck H's Avatar
    Join Date
    May 2007
    Location
    pacific north west
    Posts
    15,340
    Thumbs Up/Down
    Received: 2,318/4
    Given: 2,699/0
    Rep Power
    30
    Quote Originally Posted by Enzo View Post
    I use nice radial 0.047/630v caps in them, one inch leads, and I have to clip the old wires off at the old cap body, then splice the new cap to the old wires. Looks crappy.
    I've done that on two Mesa boards where you would otherwise have to unsolder half the flying leads to lift the board. Bah! I just snip the old caps out leaving the leads and actually bend hooks into the lead connections for the new caps. I'm certain as good a connection as done otherwise. And yes, looks like crap and I took some heat for admitting it here before.

    3 Not allowed! Not allowed!
    "Never bet your life on somebody else doing their job." SoulFetish's good friend

    "Now get off my lawn with your silicooties and boom-chucka speakers and computers masquerading as amplifiers" Justin Thomas

    "Being born on third base and thinking that you must have hit a triple is pure delusion!" Steve A

    "Back to the amp. It makes horrible sounds when I play my guitar thru it... because I suck at playing guitar." Mike6158

  17. #17
    Don't forget the joker g1's Avatar
    Join Date
    Feb 2010
    Location
    Canada, somewhere north of Fargo
    Posts
    11,753
    Thumbs Up/Down
    Received: 1,613/23
    Given: 4,125/11
    Rep Power
    22
    Quote Originally Posted by Chuck H View Post
    yes, looks like crap and I took some heat for admitting it here before.
    I blame a lot of the current fetishization of aesthetics (with regard to amp guts) on the diy builders with no electronics knowledge. It's much easier to obsess over the angle of a wire bend than to actually learn whether it is relevant, or even counterproductive.
    Your choice to NOT flip that board could have added a year (or more) to it's reliability, for all we know.

    2 Not allowed! Not allowed!
    Just because they don't have tubes doesn't mean they don't have feelings! - glebert

  18. #18
    Member HaroldBrooks's Avatar
    Join Date
    Mar 2019
    Posts
    201
    Thumbs Up/Down
    Received: 117/0
    Given: 636/0
    Rep Power
    1
    Quote Originally Posted by g1 View Post
    I blame a lot of the current fetishization of aesthetics (with regard to amp guts) on the diy builders with no electronics knowledge. It's much easier to obsess over the angle of a wire bend than to actually learn whether it is relevant, or even counterproductive.
    Your choice to NOT flip that board could have added a year (or more) to it's reliability, for all we know.
    I very recently got out of the habit of wanting everything to look perfect in terms of orientation of components. I've experimented with slight repositioning of caps and resistors, and the only benefit seems to be when you move a component away from a high voltage line or pin. I have spend hours trying to get things to "Look" right, but I am done with it. As long as my solder joints are good, the components are solidly mounted, and nothing is too close to anything else or not able to spontaneously create a short, I've done my job.

    It's easier for me because to date I've only worked on my own amps, and work they do. If you work fixing amps, you need to be aware of sniping that goes on if your work is brought to a tech who makes his living of criticizing others work, and redoes stuff that was perfectly fine the way it was.

    This type of stuff has been done for years in many different repair areas, including automotive.

    If it ain't broke, don't fix it is mostly (but not always) true, with the exception of something that is truly an accident waiting to happen like a part flopping around or a positive voltage lead almost touching ground.

    Not having a resistor or capacitor with the exact same leads bent at a perfect 90 degree angle is not a problem of any sorts, IMHO.

    1 Not allowed! Not allowed!

  19. #19
    "Thermionic Apocalypse" -JT nickb's Avatar
    Join Date
    Dec 2009
    Location
    Devon, UK
    Posts
    3,560
    Thumbs Up/Down
    Received: 757/1
    Given: 600/1
    Rep Power
    13
    ..or redoing stuff the wasn't perfectly fine:-

    Click image for larger version. 

Name:	DSC_0026.JPG 
Views:	86 
Size:	1.62 MB 
ID:	53673

    1 Not allowed! Not allowed!
    Experience is something you get, just after you really needed it.

  20. #20
    Master Destroyer nosaj's Avatar
    Join Date
    Sep 2011
    Location
    Pace, FL
    Posts
    3,213
    Thumbs Up/Down
    Received: 1,093/102
    Given: 146/35
    Rep Power
    12
    Quote Originally Posted by nickb View Post
    ..or redoing stuff the wasn't perfectly fine:-

    Click image for larger version. 

Name:	DSC_0026.JPG 
Views:	86 
Size:	1.62 MB 
ID:	53673
    What the heck is that?
    nosaj

    0 Not allowed! Not allowed!
    Binkie McFartnuggets‏:If we really wanted to know the meaning of life we would have fed Stephen Hawking shrooms a long time ago.

  21. #21
    "Thermionic Apocalypse" -JT nickb's Avatar
    Join Date
    Dec 2009
    Location
    Devon, UK
    Posts
    3,560
    Thumbs Up/Down
    Received: 757/1
    Given: 600/1
    Rep Power
    13
    Quote Originally Posted by nosaj View Post
    What the heck is that?
    nosaj
    Ampeg portaflex. The main triple filter cap had been replaced by a three radial caps siliconed and tywrapped to a bamboo cane. The cane was siliconed to the chassis. It was all loose and floating around.

    1 Not allowed! Not allowed!
    Experience is something you get, just after you really needed it.

  22. #22
    Bent Member Chuck H's Avatar
    Join Date
    May 2007
    Location
    pacific north west
    Posts
    15,340
    Thumbs Up/Down
    Received: 2,318/4
    Given: 2,699/0
    Rep Power
    30
    Quote Originally Posted by nickb View Post
    Ampeg portaflex. The main triple filter cap had been replaced by a three radial caps siliconed and tywrapped to a bamboo cane. The cane was siliconed to the chassis. It was all loose and floating around.
    That's just stupid!..

    Anyone knows you need to use hot glue for bamboo.

    4 Not allowed! Not allowed!
    "Never bet your life on somebody else doing their job." SoulFetish's good friend

    "Now get off my lawn with your silicooties and boom-chucka speakers and computers masquerading as amplifiers" Justin Thomas

    "Being born on third base and thinking that you must have hit a triple is pure delusion!" Steve A

    "Back to the amp. It makes horrible sounds when I play my guitar thru it... because I suck at playing guitar." Mike6158

  23. #23
    Old Timer J M Fahey's Avatar
    Join Date
    Oct 2007
    Location
    Buenos Aires, Argentina
    Posts
    11,753
    Thumbs Up/Down
    Received: 1,881/23
    Given: 1,463/35
    Rep Power
    27
    Quote Originally Posted by SoulFetish View Post
    What I can't understand at all, is how any self respecting modern manufacturer sells an electrolytic with a temp rating of 65˚!!!
    I would never spec a capacitor in an amplifier build with a capacitor temperature rating like that, particularly in a tube amp.
    having said that, I really never see them fail. My observation working on amps that use atom filter caps is that they may actually be a pretty reliable cap.
    I bet the actual rating is 105C , if anything because they have the huge production line setup for that, period, but they have to PRINT 65C because some mojohead complained the modern ones have "cold analytical brittle sound" ... after reading the label that is

    2 Not allowed! Not allowed!
    Juan Manuel Fahey

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Similar Threads

  1. Sprague Tel-Ohmike TO-6A
    By TomCarlos in forum Maintenance, Troubleshooting & Repair
    Replies: 7
    Last Post: 12-06-2016, 02:20 PM
  2. Upgrading a Bandmaster filter caps question Srague Atom versus Illionois brand
    By Slobrain in forum Maintenance, Troubleshooting & Repair
    Replies: 7
    Last Post: 03-04-2014, 01:32 AM
  3. How long are Sprague Atom filter caps good for time wise?
    By catnine in forum Maintenance, Troubleshooting & Repair
    Replies: 11
    Last Post: 11-30-2012, 09:36 PM
  4. bias caps: Sprague Atom or Xicon?
    By mike_mccue in forum Maintenance, Troubleshooting & Repair
    Replies: 8
    Last Post: 05-03-2008, 11:37 PM
  5. Sprague vs. Mallory caps
    By pvsage in forum Mods & Tweaks
    Replies: 11
    Last Post: 08-16-2007, 09:49 PM

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •