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She's a Breakin Up Cap'n

Discussion in 'Amps and Cabs [BG]' started by bizzaro, Aug 12, 2001.


  1. bizzaro

    bizzaro

    Aug 21, 2000
    Vermont
    AMP WIZARDS

    My practice amp is showing signs of stress.
    The signal breaks up as it is processed by the amp. It seems to be sensitive to attack(volume) and specific pitch. Specifically G in any octave. At first I thought it was the speaker, but have used the amp on another cab and got the same results. It is a not a valuable amp and I am wondering if it is worth fixing. I am guessing there is a short in the circuit board somewhere? How hard is that to find and fix if that is the case? It is a Carvin 150 watt pro. Any Ideas what could be causing this? :confused:
     
  2. steinbergerxp2

    steinbergerxp2 Guest

    Jul 11, 2001
    Perhaps an active bass with a dying battery?
     
  3. bizzaro

    bizzaro

    Aug 21, 2000
    Vermont
    Nope. I thought that was it but disproved it with different guitars and new battery. But thanks for the effort. I also used different guitar cables. I have pretty much narrowed it down to the amp. ;)
     
  4. steinbergerxp2

    steinbergerxp2 Guest

    Jul 11, 2001
    I would then try and narrow it down to electronics or speaker. My money is on a dying speaker because mechanical always dies before electronic it seems.

    www.partsexpress.com has lots of speakers.
     
  5. bizzaro

    bizzaro

    Aug 21, 2000
    Vermont
    At first I thought it was the speaker, but have used the amp on another cab and got the same results. (How do you do that quote thing) :confused:
     
  6. steinbergerxp2

    steinbergerxp2 Guest

    Jul 11, 2001
    You click on the QUOTE button above a post you wish to reply to (at least I can provide SOME help).

    Is it possible you have something microphonic? Does thumping on the head make any difference in the nasty sound? I don't recall ever hearing about solid state microphonics but tubes will do that.
     
  7. bizzaro

    bizzaro

    Aug 21, 2000
    Vermont
     
  8. bizzaro

    bizzaro

    Aug 21, 2000
    Vermont
    So how do you select just a part of a post?
     
  9. Does it happen at all volumes or only at high levels?
     
  10. Chasarms

    Chasarms Casual Observer

    May 24, 2001
    Bettendorf, IA USA
    I just delete out the part I don't want.

    As for the amp, all of those lower-priced SS amps are one big stamped IC. It is likely that there is a bad part on the board somewhere. It isn't uncommon for SS stuff to start to show its signs or wear as it heats up. The part is probably about 80 cents, but the problem is isolating it. It is a reasonabley complex circuit.

    I doubt it is worth fixing. It wouldn't take very long on the bench to get up around the $200 mark with techs charging 80-90 bucks an hour.

    Is the amp worth much more than that?
     
  11. bizzaro

    bizzaro

    Aug 21, 2000
    Vermont
    Yea it pretty much happens at all volume levels. I notice it most at moderate volumes because it is loud enough to be annoying, and when I have the amp cranked I am usually trying to hear myself above the guitar heros and it is all distorted anyway.
     
  12. bizzaro

    bizzaro

    Aug 21, 2000
    Vermont
    Thanks for the info. ON both counts. I will probably mess with it myself and get electrocuted!(sp) I don't know how to throw things away! And it is not worth taking it in for repair.:(
     
  13. brianrost

    brianrost Gold Supporting Member

    Apr 26, 2000
    Boston, Taxachusetts
    You can always isolate it a bit further by checking the signal before and after the effects loop. That way you can at least figure out if it's the preamp or the power amp that's sick.

    For example, I have an old Dean Markley bass head where the power amp section works fine but the preamp makes weird cracking sounds after it warms up. So now I just use the head as a power amp to drive my PA monitors :)

    I suppose if the power amp had been the culprit, I'd have tossed it though :)
     
  14. bizzaro

    bizzaro

    Aug 21, 2000
    Vermont
     
  15. bizzaro

    bizzaro

    Aug 21, 2000
    Vermont
    Ok so why isn't the quote bold? It worked last time?
     
  16. Chasarms

    Chasarms Casual Observer

    May 24, 2001
    Bettendorf, IA USA

    You deleted the [/B][/QUOTE] off the end of it.

    Chas
     
  17. bizzaro

    bizzaro

    Aug 21, 2000
    Vermont
    Thanks Chas. I thought I went back and put it back in, But apparently not!!