Adcom GFA-555 ii power amp filter caps

Collapse
X
 
  • Time
  • Show
Clear All
new posts
  • Electone
    Member
    • Mar 2016
    • 19
    • Canada

    #1

    Adcom GFA-555 ii power amp filter caps

    I picked up a mint 555ii last week and I'm just going over it. I did some measurements on the four big filter caps and it seems one of them may be dying. They are the original Adcom 15,000uF 100V caps.

    1. 15.96mF, ESR 1.2ohm, Vloss 0.9%
    2. 10.16mF, ESR 1.2ohm, Vloss 1.6%
    3. 15.92mF, ESR 1.3ohm, Vloss 1.9%
    4. 15.36mF, ESR 1.2ohm, Vloss 2.3%

    Questions are would it be ok to leave things as they are, or should I replace cap #2 or replace all four.

    The amps sounds perfectly fine as is and is very powerful.

    Thank-you in advance.
  • redwire
    Badcaps Legend
    • Dec 2010
    • 3906
    • Canada

    #2
    Re: Adcom GFA-555 ii power amp filter caps

    Nice!
    I would run the amp for a while, the caps might just need reforming, if it was out of service for a time. Then recheck the capacitance... But not in-circuit.
    They are expensive caps to change out.

    Comment

    • Electone
      Member
      • Mar 2016
      • 19
      • Canada

      #3
      Re: Adcom GFA-555 ii power amp filter caps

      Sounds like a plan. Exact replacements would be cost prohibitive. I was looking at some CDE 382LXs but they are not screw terminals, so i'd have to modify the connections.

      Comment

      • budm
        Badcaps Legend
        • Feb 2010
        • 40746
        • USA

        #4
        Re: Adcom GFA-555 ii power amp filter caps

        You may not even notice anything unless you run the amp at full output power spec..
        Never stop learning
        Basic LCD TV and Monitor troubleshooting guides.
        http://www.badcaps.net/forum/showthr...956#post305956

        Voltage Regulator (LDO) testing:
        http://www.badcaps.net/forum/showthr...999#post300999

        Inverter testing using old CFL:
        http://www.badcaps.net/forum/showthr...er+testing+cfl

        Tear down pictures : Hit the ">" Show Albums and stories" on the left side
        http://s807.photobucket.com/user/budm/library/

        TV Factory reset codes listing:
        http://www.badcaps.net/forum/showthread.php?t=24809

        Comment

        • redwire
          Badcaps Legend
          • Dec 2010
          • 3906
          • Canada

          #5
          Re: Adcom GFA-555 ii power amp filter caps

          The CDE screw type cans are over $100 each, ouch. But only 75V or 100V. Snap-ins are $17 each. Not sure why.

          Comment

          Related Topics

          Collapse

          • momaka
            HannStar Hanns-G HC194d LCD monitor repair
            by momaka
            Normally, I never post repairs this quick after I do them, because… I am usually very slow. But today, I’m making an exception here. Why? No idea. Perhaps only because the repair details are still “fresh” in my head… which is ironic, given this is a 16 year old monitor that hardly anyone will care about today. It is new to me, though. I picked it up last November from someone on my local Craigslist. It wasn’t very close to where I live, but was close to a family friend that I had to go visit anyways. So after watching the posting on Craigslist for a few weeks and seeing it getting...
            03-15-2023, 10:17 PM
          • Paxman_Swede
            Identifying caps on an old Zoom 9000
            by Paxman_Swede
            Hello!

            I have two projects on my work bench. One is a friends dead JBL Xtreme speaker with a blown voltage regulator and corresponding bulged and shorted cap. That cap has clear markings so I know what replacement I need for it.

            The other project however is a whole different deal. It's a Zoom 9000 guitar effect from the 90th that has developed a devil hound howl when there is no input from the guitar. I'm guessing caps problem. So, since I don't really use this effect anymore I thought it would be a perfect project to learn on.

            I have studied the board and...
            01-14-2025, 09:51 AM
          • momaka
            Seasonic B12 BC-550 – barely 2 years old and with BAD CAPS already!
            by momaka
            I know I've been a little scarce lately (like the last 2-3 years), but I'm still here and still doing my thing with fixing PSUs.

            For today's considerations, I have a Seasonic B12 BC-550 [A551bcafh] 550 Watt ATX power supply for you (click on links for full size images).

            https://www.badcaps.net/filedata/fetch?id=3591771


            https://www.badcaps.net/filedata/fetch?id=3591772

            It's a modern ATX unit with fixed (non-modular) cables and an 80-plus bronze certificate. Here's the label:

            https://www.badcaps.net/filedata/fetch?id=359177...
            03-12-2025, 03:42 PM
          • captain150
            Help with switching power supply caps
            by captain150
            I'm trying to repair two old VCRs, they both have bad caps. One has leaky ones, the other would barely run until I subbed in some caps from another power supply I had laying around (though they are the wrong values). This vcr works for an hour or two, but then the power supply starts whining and the picture gets lines in it. I didn't replace all the secondary caps, so another voltage might still be problematic, or the values I used are too far off.
            I've been on mouser and digikey but the options are a bit overwhelming. I just need some new ones that will work. They don't need to be top quality,...
            03-16-2025, 07:34 PM
          • Foetuss
            Gigabyte GA-6OXT :: caps question
            by Foetuss
            Good evening

            I recently aquired a rev 1.1 Gigabyte 60XT, and was suprised of the amount of leaking caps for a motherboard of the P3 era. Especially the way the 330µf caps seems like the housing discolored even.
            Now, there are some 3300µF 6.3V KZG series around the CPU. Would it be OK to replace them with something like EEUFR1A332 ? (Panasonic FR 3300µF 10V). Or was this board designed around very low ESR caps?

            But I was also suprised about the bigger boys, which are 330µF 25V.
            Could it be they used 25V caps because they were cheaper / available at that time?...
            02-11-2025, 12:22 PM
          • Loading...
          • No more items.
          Working...