Vibration sound

Discussion in 'Amps/Cabs Tech Corner: Amplifier, Cab & Speakers' started by dkals, Feb 17, 2008.


  1. dkals

    dkals Member

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    I am new to tube amps. I bought a new Palomino V32. Found out the reverb tank had 2 of the springs come off and three of the four wires in the tank had to be re soldered.

    Now I am beginning to play with it, tone & volume. When I turn up the volume certain notes on the low E string give a vibration / distortion sound. I have checked for loose speaker & loose parts. Nothing. Could it be the tubes vibrating? Thanks
     
  2. rockon1

    rockon1 Member

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    Check the rear panel. It has 6 screws holding it on. Mine was vibrating at louder volumes. Try tightening them . I had to put some thin self sticking foam on the chassis on mine where it meets the cover and that took care of it. Hope your enjoying it otherwise -love mine! Bob
     
  3. dkals

    dkals Member

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    I have taken it apart. Nothing is loose. Is it possible for tubes to make a vibration sound and come through the speaker?

    It happens only if you play low E & A frets 3 through 7.

    Thanks
     
  4. rockon1

    rockon1 Member

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    Yes tube rattle is possible but so is "resonant" vibration.Is it coming thru the speaker?Sometimes its very difficult to tell I know. Also its much easier to find this type of thing with two people. One playing the offending note and the other grabbing parts to deaden them. FWIW- My rear panel wasnt loose yet still vibrated at certain notes against the chassis to which its screwed. Thats why I ended up using the foam between it and the chassis. Not saying this is your problem just one I found on mine.

    Other things that sometimes cause rattles- Tube retainers(the cans that go over the pre amp tubes). Some one posted the tube cage rattling on thiers if I remember correctly too.

    Its always a good idea to have spare sets of power tubes for any amp you own. They come in very handy for at least troubleshooting stuff like this. You can determine if they are the cause right away but swapping them out. Besides if a tube fails youve got backups on hand. Good luck Bob
     
  5. vibroverbus

    vibroverbus Member

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    This amp is new-new? A 'slightly bad' speaker can cause an intermittent resonant buzz exactly like that as well - either from a slightly warped former or crap-in-the-gap, so to speak... But if this is new you'd expect that to not be a problem, and I'd be chasing mechanical stuff first...
     
  6. dkals

    dkals Member

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    Thank you for the help. I have two options. The AMP is under warranty so I can take it in and let someone fix it. Or I can get new tubes and replace them out.

    Bob can the cans on the pre amp tubes be tightened or does the whole thing have to be swaped out? Also since you know this amp so well any recomendations on tubes?

    Thanks Don
     
  7. rockon1

    rockon1 Member

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    Well like I said finding or determining whats causing a noise can be difficult so the process of elimination is a good one. If you can make the amp make the noise and still grab /hold things by yourself you might get lucky. Thats how I found the back cover vibration. Hit an offending note and grabbed around. When I put my hand on the back cover it stopped making noise. I was surprised since I didnt think that would be a possible cause. This is all fine and well if its a vibration noise that is and not something else....On many amps you could grab the power tubes with an oven mit and see if it goes away but these are well hidden and caged.

    The cans cant really be tightened but sometimes if you twist them slightly they will stop vibrating. On these amps however the cans are probably less likely than others Ive seen to vibrate. The spring inside them exerts a pretty strong pressure holding them fairly snugly in place. Careful though if you twist thenm too much they will come off and are a mother to get back on because of the location. When I mentioned them honestly I was thinking of some of my other amps that have much weaker springs inside them are are much more prone to rattle.

    For new production tubes I go with JJ's for EL84 amps. Mike at KCA can hook you up. 40$ for a set.

    http://kcanostubes.com/content/Default.asp

    . Even though its new and under warrenty having a spare set is a must in my book.

    Worst case if you cant determine the cause/origin of the noise you can bring it in under warranty. Personally if its really something vibrating I'd rather find it myself if possible. Sorry I cant be of more help. ithout hearing the noise this is speculation. Bob
     
  8. Groovey Records

    Groovey Records Member

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    When I was trouble shooting my amp I turned it around and removed the rear access panel and played through all the tone settings , chords, attacks sustained notes, etc while keeping an ear on the amp for acoustic noise from the tubes.

    I've been told all tubes can be microphonic but for me its been the EF86.

    I ended up using Halo Dampeners on some tubes to kill the ching a ling sound of rattling glasses. They really help. Still I search for good sounding EF86's that are stable and not Microphonic.

    [​IMG]

    Enjoy The Music
    Groovey Records
    Listening to James Burton and Ralph Mooney
    Corn Pickin and Slick Sliding
     
  9. dkals

    dkals Member

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    Can it be dangerous reaching around inside an amp when the power is on?

    At first I thought the sound was coming from the back of the amp. The reverb tank is secure and so is the speaker. I took off the back panel no change. I put the back panel on tight no change. The sound does seem like it is coming from the speaker but only on high volumes and like I mentioned only on certain notes on low e and a. I thought if it was a bad speaker playing an open low e would make it vibrate but it does not.

    You know how you can shake a light bulb that is going or has gone bad and you hear the filament? That is what it sounds like, but amplified. The sound on the same notes does not happen when the volume is decreased.
     
  10. Groovey Records

    Groovey Records Member

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    Yes it can be dangerous, But if all you are doing is gently tapping (GENTLY)
    (TAPPING) a tube with a pop stick or pencil you will live to tell about it.

    Use your ears while you a playing Loud and listen for acoustic noise off the tubes at the same time its coming out the speaker. Then gently tap the tube or even just hold the stick against it and see if is sensitive to touch.

    Do not shake your tubes like light bulbs. Tubes are hyper sensitive and you can damage a good tube. Don't shake your light bulbs either if it don't go on it doesn't work.

    You might have speaker rub but its most likly a tube

    Good Luck

    Let us know what it is when you figure it out

    Groovey Records
     
  11. rockon1

    rockon1 Member

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    No its not really dangerous to reach around the amp where the tubes and such are. I change mine all the time with the power still on. Reaching actually inside the amp (under the back cover IS dangerous). BTW-You cant check the amp with the cover off. The nuts for the cover scres will rattle like all hell.
    From your description it does sound like perhaps you got tube rattle.
     
  12. rockon1

    rockon1 Member

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    On the V32 its impossible to tap on the power tubes with the chassis in the amp. It would need to be removed . Even the pre amp tubes are very difficult to access. Bob
     
  13. dkals

    dkals Member

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    Yeah when I first took off the the back and took out the chasis I thought it was the nuts but realized when the back cover is on the nuts would be secure.

    Bob, if is tube rattle would new tubes fix that or would the new tubes rattle also? Is there a way to tighten or adjust the current tubes? Or do I take it into the shop?

    Thanks Don
     
  14. rockon1

    rockon1 Member

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    Maybe Ive been lucky but Ive yet to experience tube rattle with my V32. Ive tried 5 different sets of power tubes(for tone -not because they were bad) and none rattled. If it is tube rattle then new tubes should fix it.Whether or not you should try tubes or take it back under warranty is a personal decision.
     
  15. Groovey Records

    Groovey Records Member

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    LeT us know what is is when you figure it out. I didn't know this amps lay out,
    can the Palamino power up and run with the chasis removed from the cab?

    That would make things easier to DIY. Talking with Palamino might help this might be something they've come across before

    Anyway let us know how it goes
    EnJoY ThE MuSiC
    Groovey Records
     

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