Yellow Astron caps

Discussion in 'Amps and Cabs' started by brad347, Mar 13, 2006.

  1. brad347

    brad347 Member

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    Any thoughts on these? Some people say they're all leaky and can be dangerous for your tubes and (worst case) transformer. I say my new-to-me brown super is full of 'em and sounds good. Some say they should all be replaced. I say that makes me nervous. What do you say?
     
  2. hogy

    hogy Member

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    They do go leaky (meaning they'll let DC voltage pass through, not that they actually leak some liquid) more than other old caps.
    There is, however, no need to replace them all. I despise that shotgun approach when it comes to vintage amps. If your tech can't test them and determine which ones are bad, you need to find another tech.

    They cannot damage tubes or transformers, that applies to the electrolytic power supply caps in your amp. Your Astrons function as signal/coupling caps. If the leak DC, they will throw off the bias of the preamp stage tey're feeding into, which will cause bad tone. In some circuits your controls can sound scratchy because of leaking coupling caps.

    If your amp sounds fine, don't worry about it.


    Hogy
     
  3. brad347

    brad347 Member

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    awesome thanks hogy. Someone in another thread was suggesting that if they threw off the preamp tube bias that could cause redplating and worst case possible damage to the OT. This sounded unlikely to me but I'm no tech.

    I also hesitate on the shotgun approach.
     
  4. sideman

    sideman Member

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    Just a quick ditto to Hogy. Alot of guys seem to recommend stripping all Astrons out of tweeds and browns, and blue tube Mallorys out of BF. Yet most vintage freaks love that stuff for the look and the tone. Your tech should be able to test each cap and resistor and isolate the bad ones. Recently my tech reported that the majority of the Astrons in an all original 5f6a that I brought him were, to his surprise, just fine.

    %F^-Ad r e
     
  5. brad347

    brad347 Member

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    besides... totally dorky but... the Astrons look cool.

    I find that the cooler stuff looks the better it sounds. This is a tested and proven theorem. :)
     
  6. ES350

    ES350 Member

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    Changed out the Astron tone caps to Mallorys/paper in oil/other in my tweeds as an experiment and it was terrible...back they went and they're staying. Other old Astron pulls have functioned pretty well as guitar tone caps...
     
  7. brad347

    brad347 Member

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    validation is sweet :)
     
  8. redtoploader

    redtoploader Member

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    Hey Brad347-

    I too have a super with all astrons, its an early '61. It sounds great so they are staying for now- I also don't like the shotgun approach to caps. HOWEVER the astrons that may be of concern are the output coupling caps...when these leak, they can mess up your bias voltage and redplate your power tubes. If you are going to gig with the amp, I would put some reliable caps in place of those, and keep the astrons to put back in case you want to sell the amp down the line. Its just a good insurance policy. These dont influence your tone like the ones in the preamp section. I had an old tremolux and an ampeg jet with the same problem.

    Leave the astrons in the tone section though! You'll know if a coupling cap goes real bad, it will sound like a blown speaker. Scratchiness when you turn the volume control will indicate some leakage too.
     
  9. McCauley

    McCauley Member

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    Brad, I picked up a 61 brown super a little while back and the tech that had it before gutted it and filled it with orange drops, it sounds great but it might have sounded better before !? The thing is the 2-1/2 tube trem works better on this super than on my all original 61 concert, so it's kind of a trade off. I usually use the normal channel anyway. What kind of speakers do you have in yours ? I have alnico oxfords in both of mine and love 'em, I honestly don't understand why they get bad rap.
    I'd like to replace the orange drops in the signal path of my super, any reccomendations ?
    Mike
     
  10. brad347

    brad347 Member

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    Original alnico Oxfords in mine too, they sound awesome. Orange drops are fine caps. Some people recommend other more boutique-y caps but I can't comment, very little experience. I've owned amps with orange drops, blue mallorys, and now yellow astrons but that's it.

    Isn't that phase-shifting trem awesome?
     
  11. brad347

    brad347 Member

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    ps i think word is starting to get out on these brown supers... one went for $1800 after shipping on ebay yesterday... I got mine for about $1000 on Saturday but it's pretty beat cosmetically. I think these are awesome amps!
     
  12. hogy

    hogy Member

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    That's possible, but very unlikely. The coupling caps would have to be really blown for that to happen, not just leak a little. I've never seen it happen.
    It would also be unlikely for those caps to fail catastrophically in an instant. They're more likely to get gradually worse, so if you check your bias voltage ever so often I wouldn't worry.

    Hogy
     
  13. gnugear

    gnugear Member

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    Does anyone have a source for those Astrons? I'd like some for a restoration project.
     
  14. redtoploader

    redtoploader Member

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    This is true. In each of my cases one cap was bad and redplated one of the tubes power after being on for awhile. Not instantaneous destruction or anything.

    Well, that depends on the amp. Those red astrons(pre yellows) are REALLY notorious for going bad. On the other hand, those blue mallory's seem to be pretty solid IME. Its happened to me twice- maybe i'm unlucky.

    If they arent causing a problem now and you dont plan on gigging the amp alot than I wouldnt worry about it too much. If I was gigging it without a backup I would change them to be safe- thats just me.
     
  15. brad347

    brad347 Member

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    i will gig the amp from time to time probably but I'm betting on my deluxe getting the nod most nights. I'll sleep on it and see how it pans out.
     
  16. ES350

    ES350 Member

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    If you look around, you may be able to score some pulls on Astrons and one of the boutique tweed makers was selling pulls for stupid money...as far as I have been able to tell from my tweeds, you really only need the 1-3 tone caps for the tone stack (depending on the amp model) and a domino El Menco or Sprague silver mica...plenty of those around.
     
  17. sundaypunch

    sundaypunch Member

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    Nothing makes me run away from a vintage Fender faster than seeing these caps removed. They are a huge part of the sound. I won't even consider buying an old Fender without these caps. There is nothing worse than seeing a bunch of orange drops in one of these amps.

    If one has been replaced because it was bad that's one thing. Usually they are all gone when the tech. decided to "improve" the amp. To me it's just like a Vox that is missing the gold Wimas or a Marshall without the mustards.
     

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