Capacitors

Discussion in 'DIY' started by purr1n, Mar 14, 2017.

  1. bengo

    bengo Friend

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    It's not like they are visibly bulging or anything. Depends how much use the amp had (which you may or may not know) and the voltage (which you can measure, with tubes assume fairly high). The problem as I understand it is drying out of the electrolyte. Not sure how much is due to time and how much due to heating when actually powered up though.

    Found this which is interesting: http://conradhoffman.com/capchecktut.htm

    Edit: also depends how much you love the amp :)
     
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  2. Riotvan

    Riotvan Got lost for three weeks at Delft City Hall

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    Thanks for the link! Very nice read, from what i gather it might be a good idea to just replace the caps in the power supply.

    If only for safety reasons...

    It seem to be 85C caps mostly and i'm thinking Panasonic 105C ones as a replacement. This amp does not get too hot but has served as a cat bed in the past.

    I would like to restore and preserve this amp, i have good memories listening to it with the HD600 so some sentimental value is involved but most of the audio gear budget goes into my nearfield setup.
     
    Last edited: Nov 23, 2017
  3. bengo

    bengo Friend

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    Haha, one of those babies could take your head off!

    Check the temps (of the actual capactiors, not the case) after it's been on for a while. Most likely nowhere near 85C. If you have a suitable scope (can find cheap Chinese ones on ebay) it's also possible to see if there is much ripple on the power rails.
     
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  4. Riotvan

    Riotvan Got lost for three weeks at Delft City Hall

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    Yeah a scope might be a good idea hehe. I will also check the temp of the caps. From what i gathered 105c caps are usually higher quality then 85c ones. I do think the psu might have some problems though, there is some hum that gets worse when my plasma TV is turned on.

    Edit checked the temps, i would be suprised if they are higher than 45c. Even near the tube, i can touch them indefinitely.
     
    Last edited: Nov 23, 2017
  5. Telstar

    Telstar Bottom 1% of posters on SBAF

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    I have a friend who has also got good impressions on the jupiter, and it’s the cheapest in lampi chart I think.
     
  6. Gallic Dweller

    Gallic Dweller Acquaintance

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    And now for something for completely different - when something looks too good to be true - it probably (99%) isn't. Well here's the exception - Russianj mil. spec. K73-16 caps.

    Some years ago now a medical doctor from London started a thread about these caps on diyaudio. He had spent plenty on all the audiophool' caps but then decided to try these ridiculously cheap mil. spec. caps.

    Forget all about the Russian PIO/ Teflon caps and all the huge and I do mean huge PIO in cans type - I have plenty - want some?

    These come in aluminium shells, pinched at either end with non-inductive lead out wires. I, lioke others was totally skeptical but costing pennies each, I had to take a chance.

    These caps are the equivalent of the Z foil resistor - totally transparent. I can well understand why so many amp designers don't like to use coupling caps - because they colour the sound so much - these do not.

    It's well worth checking out this thread about K73-16 caps on diyaudio only one actual user dosn't like them. All other detractors have never used them at all.

    For what they cost it's a no brainer. Hearing is believing, I intend to take a chance using 63V ones in a part ofm the Dark Voice circuit that only sees 70V max. I have quite a lot of useful values - 0.33Uf/0.1Uf/ etc. some 400V/630V and 63V types, I can spare pairs at cost + postage, PM me - if you want truly transparent cpas try these before buying seriously expensive audiofool caqps.
     
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  7. donunus

    donunus Friend

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    try duelund caps
     
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  8. donunus

    donunus Friend

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    ^ Why the dislike? You despise Duelund caps? Those are awesome
     
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  9. Gallic Dweller

    Gallic Dweller Acquaintance

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    seriously expensive - would the rest of a piece of equipment justify shelling out for these.
     
  10. donunus

    donunus Friend

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    If it's an allout project, why not? It's at least worth trying out in the caps comparison. With my horn speakers for example, they are absolutely worthy
     
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  11. Gallic Dweller

    Gallic Dweller Acquaintance

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    Only a valid buy if the rest of the gear is of the same standard - which is what I said in my previous post. Nothing against Dueland at all - for me, parts or equipment at these kind of prices have zero - value for money - it's all about personal opinion and mentality, nothing more.
     
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  12. Garuspik

    Garuspik Tovarisch Ukrainian Terminator MOT - Verum

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    Yes, they're well known among DIYers in all ex-USSR countries. In Ukraine they cost almost zero, so they have the best price\perfomance ratio :D They can be compared with Solen.

    Among hi-fi caps I do like Obbligato copper (but never tried obbligato gold).
     
  13. donunus

    donunus Friend

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    You're talking bout the green ones right? I use those as well
     
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  14. winders

    winders Worst poster on SBAF (not a joke)

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  15. purr1n

    purr1n Finding his inner redneck

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    That would be funny if they were OEM for Dueland. I swear, most of the audiophile cap business is scammy. I have stories, but I don't want to piss off anyone.
     
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  16. willsw

    willsw Friend

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    No one wants to see Mickey take his head off. Keep Mickey's head on. It's an ugly, completely reasonable reality under there.
     
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  17. winders

    winders Worst poster on SBAF (not a joke)

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    The MiFlex KPCU 01 caps do look like Duelund clones. I have about 15 hours on them. They were a little rough to start but have continued to improve noticeably. The person that turned me on to them says 30 to 50 hours is when they get really good. I got my pair for $80. You can't argue with that price!
     
  18. sphinxvc

    sphinxvc Gear Master East

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    I like stories. Just anonymize with company names like DoucheCap.
     
  19. donunus

    donunus Friend

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  20. winders

    winders Worst poster on SBAF (not a joke)

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    I have over 50 hours on the MiFlex KPCU-01 caps now and they are really good. Initially, I was a little worried that they might need small bypass caps to bring out the high end, like the Duelund CAST caps, but that is not the case.
     

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