What causes a loud hum from an amp? really loud

danger boy
danger boy Posts: 15,722
edited May 2009 in Electronics
Without any speaker hooked up the amp.. it hums, but not to loud.. of course hooking up the speakers magnifies that hum.. i cleaned the connectors with DeOxit and it didn't help. so something must be bad... like a cap or something.

any ideas?
PolkFest 2012, who's going>?
Vancouver, Canada Sept 30th, 2012 - Madonna concert :cheesygrin:
Post edited by danger boy on
· Share on FacebookShare on Twitter

Comments

  • zarrdoss
    zarrdoss Posts: 2,562
    edited May 2009
    uasually caps going out, is it a Carver?
    · Share on FacebookShare on Twitter
  • danger boy
    danger boy Posts: 15,722
    edited May 2009
    ok.. but no it's a Marantz mono block.
    PolkFest 2012, who's going>?
    Vancouver, Canada Sept 30th, 2012 - Madonna concert :cheesygrin:
    · Share on FacebookShare on Twitter
  • zarrdoss
    zarrdoss Posts: 2,562
    edited May 2009
    about how old is it? I have a Carver doing the same thing.
    · Share on FacebookShare on Twitter
  • danger boy
    danger boy Posts: 15,722
    edited May 2009
    about 15 yrs old. i'm not the original owner of course. these things are pretty inexpensive if I can't find someone to fix it.

    send your Carver amp to Bob (Carver) himself. I hear he work's on gear still ;)
    PolkFest 2012, who's going>?
    Vancouver, Canada Sept 30th, 2012 - Madonna concert :cheesygrin:
    · Share on FacebookShare on Twitter
  • lightman1
    lightman1 Posts: 10,795
    edited May 2009
    Once more, Al....strategic placement of a ball-peen hammer.:D

    Could be a loose ground.... chassis, power supply TX.....given the age of it.
    Or you could "re-boot" it.
    · Share on FacebookShare on Twitter
  • zarrdoss
    zarrdoss Posts: 2,562
    edited May 2009
    There is a repair shop around the corner from me that I dropped it off at a few weeks ago and if has has not had a chance to look at it I will send it in to Bob instead, On yours, just for someone to look at it is about $30-$40 and if its a cap anywhere from 100-150 at least thats what I got on mine and I see those mono blocks all the time for $150 or so on CL. You might try ben, Good luck!
    · Share on FacebookShare on Twitter
  • NewHTguy
    NewHTguy Posts: 584
    edited May 2009
    I have a very low-level "mechanical hum" with my Parasound even when it is not connected to anything bu the ac outlet. You can't hear from a few feet away, but it is one of those things that irks me just knowing it is there. Seems to be fairly common, so much so that Parasound does not have any official definition for "defective" when it comes to mechanical hums.
    MAIN: Polk Lsi9s; Polk PSW505; Lsic (in box); Onkyo SR-875; Parasound 2250; Cambridge Audio 740C; LG BD370
    OFFICE: Polk Lsi7; REL T3; HK 3490; CA 840W; Onkyo C-S5VL
    BENCHED: CS20; OWM3s
    · Share on FacebookShare on Twitter
  • PSOVLSK
    PSOVLSK Posts: 5,291
    edited May 2009
    My xpa-5 does this. The buzz/hiss is in the amp itself, but it also comes through the speakers. As NewHTguy said, I can't hear it from a few feet away, but it still annoys me.
    Things work out best for those who make the best of the way things work out.-John Wooden
    · Share on FacebookShare on Twitter
  • Ricardo
    Ricardo Posts: 10,636
    edited May 2009
    If coming from the amp, probably a mechanical hum from the toroidal. There are several threads on this if you search. Could be DC current in your power, loose toroidal, or just a toroidal that will hum (loose wiring maybe?).
    _________________________________________________
    ***\\\\\........................... My Audio Journey ............................./////***

    2008 & 2010 Football Pool WINNER
    SOPA
    Thank God for different opinions. Imagine the world if we all wanted the same woman
    · Share on FacebookShare on Twitter
  • danger boy
    danger boy Posts: 15,722
    edited May 2009
    turned out to be a crack in the circuit board. not sure how that happen. had the amp for two years.. no problems. then all of a sudden a crack appears in the board? Odd.

    fixed now.. $60 and she's happy again. :)
    PolkFest 2012, who's going>?
    Vancouver, Canada Sept 30th, 2012 - Madonna concert :cheesygrin:
    · Share on FacebookShare on Twitter
  • danger boy
    danger boy Posts: 15,722
    edited May 2009
    lightman1 wrote: »
    Once more, Al....strategic placement of a ball-peen hammer.:D

    Could be a loose ground.... chassis, power supply TX.....given the age of it.
    Or you could "re-boot" it.

    that would have been my next avenue. LOL

    a ball peen hammer could take care of a lot of my problems.. both stereo and people wise. ;):p
    PolkFest 2012, who's going>?
    Vancouver, Canada Sept 30th, 2012 - Madonna concert :cheesygrin:
    · Share on FacebookShare on Twitter
  • lightman1
    lightman1 Posts: 10,795
    edited May 2009
    danger boy wrote: »
    that would have been my next avenue. LOL

    a ball peen hammer could take care of a lot of my problems.. both stereo and people wise. ;):p
    Good stuff Buddy:D
    Glad you found the problem. Sounding better now?
    · Share on FacebookShare on Twitter
  • tonyb
    tonyb Posts: 33,076
    edited May 2009
    Maybe that amp was crying out to be replaced with the MF super chargers.Glad your up and running.
    HT SYSTEM-
    Sony 850c 4k
    Pioneer elite vhx 21
    Sony 4k BRP
    SVS SB-2000
    Polk Sig. 20's
    Polk FX500 surrounds

    Cables-
    Acoustic zen Satori speaker cables
    Acoustic zen Matrix 2 IC's
    Wireworld eclipse 7 ic's
    Audio metallurgy ga-o digital cable

    Kitchen

    Sonos zp90
    Grant Fidelity tube dac
    B&k 1420
    lsi 9's
    · Share on FacebookShare on Twitter