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Amp/Speaker crackle!

Discussion in 'Amps and Cabs [BG]' started by bassdr, Feb 6, 2003.

  1. I need help figuring out what is causing this sound.

    I have a distinct "crackle" coming from my rig. It has been there the last few times I played but seems to be worse lately. The interesting thing is that it ONLY happens when I play a C, and it happens on the B-string and an octave up (not as loud) on the A-string.

    I can play the open B and the D on the Bstring, no crackle. C and it's there. It seems to be there with different speaker cabs, but louder with the Epifani T-310 than the Eden CXM-112.

    Are the tubes going bad in my Mesa Walkabout? Why would it be only on one note/frequency?

    I would think if it was a speaker problem the crackle would be there all the time, at least on the low B also.

    Any ideas?
  2. Petebass


    Dec 22, 2002
    QLD Australia
    this is a beauty....Low C note only? That would be something like 30-35 hz and 60-70 hz for the one up the octave. Have you got anything unusual in your EQ at those frequencies?

    Does it happen in every room you play in? I've got a funny feeling it may be causing something in the room to resonate.

    And as silly as this may sound, check your handles and wheels are all secure.
  3. basspro2

    basspro2 I'm seeing Gorillas...

    Apr 6, 2002
    Northbridge, Mass
    I know your not going to believe this but I just sent mine back to Mesa for repair for a similar problem .....strange..:confused:
  4. Petebass,

    Great suggestion on the handles and wheels. I will tighten everything up and see what happens. The sound is coming from the cabinet/speakers.


    Weird that your Mesa does it too? Do you think retubing it would be something to think about? What is the cost on, is it 6 tubes? Where did you send it for service? Mine is out of warranty so I don't really know where to start if it truly is an amp problem.
  5. jobu3

    jobu3 Artist formerly known as Big Joe

    Feb 17, 2002
    Mountain Top, PA
    if it sounds more like a tinkling of broken glass, (kind of like your horn itself crackling) and high pitched it could be a microphonic tube... i had one go in my old hartke head and i swore up and down that i was blowing the horn in my genz benz 410 until i isolated it to the tube preamp after realizing it was only on certain notes...

    i am not familiar with the walkabout but perhaps you can turn the preamp down/off to see if that affects it... does it happen at lower volumes as well? i know that mesa is VERY particular about their gear so you might not want tot tear it open yourself and thereby void the warranty...

    hope that you find out easily and cheaply that it is nothing catastrophic... :( ;)
  6. basspro2

    basspro2 I'm seeing Gorillas...

    Apr 6, 2002
    Northbridge, Mass
    I was told it probably was a mosfet going bad. It all happened on the 2k pot on the parametric eq.This drove me crazy for a week,like you I couldn,t figure it out ..I called Mesa and talked to Mike In tech service and he wanted it back asap. I'm going to tell you to call because bar none they have the best customer service I have ever had the pleasure of dealing with. They want there customers happy and satisfied..Nuff Said..
  7. I have had that scratchy buzzing which triggered by certain notes I hit. It was the voice coil in the speaker. Had to replace the speaker.
  8. it's gotta be something in the room! Dude, I get buzzes from my radiator or something else in my room when I play a C too (I don't have a low B string, but have a high C string; no buzzes there though). It's actually a noise coming from the frets thats annoying and not your typical fret buzz, and then the radiator heater thing, and also with my fender jazz too:D its good **** man...

    Good luck in fixing it. Let's hope its not the amp.;)
  9. It has been hard to figure out. I took the amp to practice today and ran it through a wedge monitor and got no buzz at all. (whew, not the amp!)

    The room buzzes like crazy so I took it out and put it in the garage and the speaker cab is the problem. Anybody see any reason why I can't take te grill off and unhook the speakers/tweeter one by one until I isolate the culprit?

    I'm assuming a blown speaker/voice coil

    Wonder what Epifani charges to recone???
  10. You'll be changing the impedence of the cab everytime you unplug/bypass a speaker just to determine what the problem is. You may end up needing a whole new rig. If you have 2 8 ohm speakers in there, you've got a 4 ohm load. unplug one speaker and bypass it, you've got an 8 ohm load. Leave the speakers alone. Improper impedance matching will have a high risk of ruining everything you've got, even the amp, even though you may not think so. Bring it to a pro.

    But what do I know?
  11. jondog


    Mar 14, 2002
    NYC metro area
    Not much. :)

    Removing a single speaker from the chain can't *lower* the impedance, right? Higher impedance ratings won't hurt the amp, it just won't be as loud. I'm pretty sure of this anyway, wait for a guru to confirm . . . Your strategy sounds logical to me.
  12. Well, an interesting thing happened. I talked to the guy who sold the Epifani cabinet to me and he assured me it was perfect when I got it ( and I believe him). I spent the weekend playing at church using a wedge monitor and the Peavey 6 throught the Mesa walkabout, no crackle there all weekend. I came home today and just for grins gave the tweeter control a couple of hard twists, blew the speaker input jacks out and plugged it in in the other jack, plugged in the amp and bass and......

    The crackle is gone.

    Now I'm left with either there is something going on with the amp but only transiently or the tweeter control was shorting. Could be Gremlins...;)
  13. jobu3

    jobu3 Artist formerly known as Big Joe

    Feb 17, 2002
    Mountain Top, PA
    it depends on how they are wired. if they are wired in serires inside the box then removing one will decrease the impedance (which can be damaging). if it's in parallel, it will increase it (which won't be damaging but will decrease the volume). if you are going to try this, make sure that you turn off the amp and unplug the cabinet from the it each time or you could run the risk of ruining the amp, or at the very least, blowing a fuse... i say just stick an ear in front of each speaker to see if it's the culprit. just don't blow out your ear drum, you might need it... :eek:
  14. jobu3

    jobu3 Artist formerly known as Big Joe

    Feb 17, 2002
    Mountain Top, PA
    keep us posted as to whether it comes back or not as well... :D
  15. yeah, knowing how those damned gremlins act up on you;)
  16. Rockbobmel

    Rockbobmel Supporting Member

    Don't jump to conclusions... Eliminate the simple things first. Try taking one of the side handles off and making sure all the connections are tight to the speakers. You can see in with a flashligt. My 18 was buzzing tonight. Even when the 4-10 was daisy chained the 4-10 buzzed too. It was a loose connection to the 18. Also check your jacks and speaker cable ends. Sometimes the tips loosen and you have to tighten them.
    It could be a LEAF or SEED or something foreign in the cabinet.

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