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Slight hiss and low volume from.amp when cold/first turned on.

Discussion in 'Amps and Cabs [BG]' started by Diesel Kilgore, Feb 16, 2013.


  1. So lately ive noticed that my amp will hiss the first few notes from the.bass after sitting all day and then clicked on. The volume is a touch low with the hissy notes but goes away within 4 or 5 seconds and volume and clarity is back to normal. It doesnt come back at all unless I shut it off for the night and come back to it the next day.

    Its a Carvin R1000. Should I be worried? It works fine other then that.

    But this amp has sat for probably a year before I got it. I did have to replace the output jack to the cab. But the repair was solid and its been going strong for about a month before this. Just makes me a little worried something is wrong.
     
  2. RickenBoogie

    RickenBoogie

    Jul 22, 2007
    Dallas, TX
    If it works fine after its warmed up, I wouldn't worry.
     
  3. beans-on-toast

    beans-on-toast Supporting Member

    Aug 7, 2008
    There have been a number of revisions to that amp design. I would contact Carvin customer service, provide your serial number and a description of the problem. Enquire if there are any service bulletins that deal with this issue that might help you out.

    There are a number of possibilities. One of which is that you have an intermittent connection that fixes itself when the amp heats up and metal contacts expand. The fix might be as simple as re-soldering a connection of tightening something. It could also be a bad component.

    In any event, it would hurt to ask them about it.
     
  4. Its circa 2001. I believe. I know its rather old. Im sure it says on the back but I haven't looked in awhile.

    Something else I noticed earlier. I had been playing for about 15 minutes and had the tone knob full off. I made a quick change and rolled it on almost full (more treble) and it did the same thing. Hissed and staticy for a few seconds then went away after a few notes.

    I have heard these Carvins with the "tube emulator" have kinda crappy pre- amps. Im wondering now if that could be part of the issue. Just a sucky pre- amp not responding fast enough or acting wonky?
     
  5. Does it sound distorted when it loses volume? Sounds like a leaky cap or a problem with bias as its turning on!
     
  6. arai

    arai Banned

    Jul 16, 2007
    A bad cap was my first thought too
     
  7. craig.p

    craig.p

    Sep 28, 2008
    New Hampshire
    2001? That thing's 12 years old. Even if the amp were working right, it'd still be way past due for a routine sanity check on its internals. Beans-on-toast is right: Pop the cover, unplug and re-plug all internal connectors to wipe off any oxidation, snug up all screws. Also blow out any dust, and shoot Fader Lube into all the controls' guts. 10 minute job max.
     
  8. gumtown

    gumtown

    May 7, 2007
    New Zealand
    I have had random level probs with a used tube amp I recently purchased, and found it to be the input jack switches on the passive and active inputs.
    The contacts of the jacks internal break switch needed cleaning.
    Good idea to do FX loop ones too, my previous amp used to cut out due to the same switch contacts in the return jack.
     
  9. beans-on-toast

    beans-on-toast Supporting Member

    Aug 7, 2008
    Since the amp hasn't been serviced in a while, it would be good to have a tech go through it and see if it is performing to spec, clean it up, and apply deoxit to the jacks and pots to clean and lubricate them. If that doesn't fix the scratchy sound, you might have a leaky cap in the tone circuit that needs replacing.

    Sometimes just stabbing at a single problem isn't the best way to approach these sort of issues. Amps need a checkup from time to time.
     
  10. 5port

    5port

    Oct 14, 2009
    LI,new yawk
    1) Clean effects jacks (in/out) with Deoxit.

    2) Remove ribbon connectors and clean with Deoxit

    3) Ribbon connectors on the rear board (board with speaker jacks) have a habit of walking off from vibration. Make sure they are seated.

    4) Clean pots with Deoxit if ness. Dont over do it or the pots will feel too loose (dont ask).

    5) If its a series I or II replace 12AX7.
     
  11. This was another area that I thought might be a problem. I have recently been using the active input for my Ibanez and who knows how often it was used before.

    I recently replaced the output jack and had it all apart. Everything checked out and wss very clean. I probably should do it again to check the inputs and blow any dust out.
     
  12. I'll check the caps too. Or can I? How do i tell if a cap is bad? I know that all the ribbon connections are clean because I did that a couple months ago.
     
  13. Its a series 3.
     
  14. 5port

    5port

    Oct 14, 2009
    LI,new yawk
    Dont miss the effects jacks with contact cleaner. #1 suspect. They oxidize without use.
     
  15. 5port

    5port

    Oct 14, 2009
    LI,new yawk
    Ah...no 12AX7 then.
     
  16. So im thinking thats a good thing. :D

    I'll get into during the week. Where and what should I look for in a contact cleaner? Hardware store? Radioshack?
     
  17. 5port

    5port

    Oct 14, 2009
    LI,new yawk
  18. Passinwind

    Passinwind I know nothing. Commercial User

    Dec 3, 2003
    Columbia River Gorge, WA.
    Owner/Designer &Toaster Tech Passinwind Electronics
    Radio Shack sells a couple of different flavors. I use the gold at least as much as the red in my shop.
     
  19. seamonkey

    seamonkey

    Aug 6, 2004
    It probably has a soft start.
    A relay is off when you first turn it on, and power goes through a resistor for a few seconds to start charging the power caps. Then the relay clicks on to provide full power.
    No big worry if there's some output before it clicks into full power but as mentioned call Carvin.
     

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