Help! Ampeg V4B Rattle

Discussion in 'Amps and Cabs [BG]' started by Sgramza, Jun 11, 2021.

  1. Sgramza


    Oct 19, 2018
    I just purchased a new Ampeg V4B RI with a 212av cab from guitar center. Love the all tube tone, however, at certain frequencies (when i play a G# or A on the A string or E string), something inside the V4B was rattling. Took it back to GC and they got me a replacement unit. Unfortunately, with the replacement unit I had the same exact issue. Its not coming through the speaker, so pretty certain its not wiring/electrical issue. It is definitely a vibration induced rattle. Really dont want to return the amp because I otherwise love it, but having a hard time justifying the money I spent on this for it to not be absolutely perfect. Also dont know that swapping for another from GC would be worth it since both units I got had this issue.

    Has anyone else had this issue and know what might be going on? All replies appreciated! I have a local Ampeg tech who can fix it under the warranty if we can diagnose the issue. Thanks!
  2. JimmyM


    Apr 11, 2005
    Apopka, FL
    Endorsing: Yamaha, Ampeg, Line 6, EMG
    Check the tube holders for the little tubes. If I'm not mistaken, they have metal covers over them. Those could be rattling. If I'm wrong about that, check the bear trap tube holders for rattles.
    Border, JKB1957 and Buster Brown like this.
  3. Nighttrain1127

    Nighttrain1127 Supporting Member

    Nov 27, 2004
    Near Worcester MA
    Some of the more recent Ampeg 212AV cabs have had some Vibration Issues. It is not the speakers making the noise it is the cab itself. Take the head off of the cab and put it on the floor and see if it still does it. My bet is the cab itself is vibrating and making the noise and it should not be.
  4. Lammchop93

    Lammchop93 Supporting Member

    Feb 4, 2007
    Louisville, KY
    Moosehead1966 and Ed Byrnes like this.
  5. beans-on-toast

    beans-on-toast Supporting Member

    Aug 7, 2008
    The fix should be simple. Finding the source can take some time. First, narrow it down by removing the head from on top of the cab. Play and determine if the buzz is from the head or the cab.

    If it’s from the head something is loose. while playing, have someone apply pressure to the top, then the front grille, then the back grille to see if the buzz can be dampened. Try sliding a business card in between the chassis and the cabinet in the top middle where the switches are.

    If that doesn’t resolve it, something in the amp is loose. It will have to be opened and all the fastening points, nuts, and screws checked.
  6. Wasnex


    Dec 25, 2011
    I recently bought a Mesa D180. It sounded great but had a rattle that was coming through the speaker that I traced to V3, which is the phase inverter. This is a 12AT7 tube. I rolled a few new 12AT7s into the amp and the rattle changed a bit but did not go away entirely until I tried a NOS Mullard CV4024.

    In my experience it's pretty weird for the phase inverter to be so sensitive to this sort of mechanical rattle, but I guess the D180 design is a bit different. The Mullard is darker and more HiFi than the other tubes I tried, which is not what I was going for, but the rattle was driving me nuts so it staid in the amp.

    I have no idea how the sensitive the V4B is to this problem. But Ampeg could have gotten a bad batch of tubes. Or the problem may have absolutely nothing to do with the tubes.

    Good luck.
  7. Wood and Wire

    Wood and Wire

    Jul 15, 2017

    Whilst the tube retainers, and the cabinet are the most likely candidates, the very first thing I would do is wedge something into the carry handle, to check that isn't rattling.
  8. Sgramza


    Oct 19, 2018
    Nothing is rattling when I take the head and rest it on the floor, therefore, pretty sure its one of the tube holders or covers and not the cab. Will try more of your suggestions here in a bit. Can anybody offer advice on whether i can check those covers and holders without electrocuting myself? Would obviously check with everything off and unplugged.
    dogbrained and Ed Byrnes like this.
  9. It's not the back cover grate?

    Pushing on it gently while playing the offending note should tell you
  10. Sgramza


    Oct 19, 2018
    Nope, not the back grate. Definitely sounds like it is inside the head and is a metal or glassy sounding vibration
  11. Sgramza


    Oct 19, 2018
    Appreciate the help, all. Jimmy M, is that something I can do without worrying about zapping myself? New to the tube game, so being extra cautious here.
    JimmyM likes this.
  12. beans-on-toast

    beans-on-toast Supporting Member

    Aug 7, 2008
    Turn the amp off. Don’t touch anything that you don’t need to. Remove the covers on the small tubes. Push down, twist, pull off. Make sure that the tubes are seated in the sockets. Rock them downward.

    Then check the power tubes.

    The speaker cab must always be connected when the amp os powered up. Turn on the power and test.
    JimmyM and Wasnex like this.
  13. Wasnex


    Dec 25, 2011
    I don't own one of these amps so I had to search for an image:
    So the tube covers are similar to this:

    Note the mount on the bottom is connected to the chassis, which is at ground potential; so there should be no risk of electrocution to touch and remove the covers. The small signal tubes themselves may be rather warm; possibly hot enough to burn you. The 6L6GCs will be scalding hot, so do not touch them.

    The tube covers have a bayonet type mount. To remove, you typically need to press down slightly and then rotate the cover so the channels in the cover are line up with the bayonets.

    A couple more images so you see some of the possible differences in the design:
    =tbn:ANd9GcRJn1_Bb8B9Xc7TmRCgWUPQy1r9D5-5meAzoPlc7oSfUMj_YWx_QEIAp2ewS8otHDMS1mIRMpQD3A&usqp=CAc.jpg upload_2021-6-11_16-41-31.png

    You can probably run the amp without any of the tube covers installed. Sometimes the cover on V1 is more important because it shields out hum. Explanation: V1 tends to be pretty high gain, so it may be more effective at picking up hum. The covers also stabilize the tubes, so they don't work there way out of the tube sockets.
    Border, Moosehead1966 and dogbrained like this.
  14. raybone


    Jul 14, 2006
    A.C Jersey
    All my tube amps (SVT, Bassmans, Sunn) make those strange glassy/metal ringing noises every now and then. Its from the vibrations, probably tubes or tube retainers, and even occurs when not on top of the cab being used. I usually move the head around a few inches one way or other, most times it gets rid of it. But, sometimes moving the amp/cab also moves the offending frequency up and down the neck. I also have put a piece of foam between cab and head, that has worked in the past too. Tube dampers could help too, the little O-rings that slide over the tube.
    Last edited: Jun 11, 2021
  15. JeezyMcNuggles


    Feb 23, 2018
    Santa Maria, CA
    I suck, but nobody really notices
    Are you sure it's the amp? Becuase, the amp doesn't produce sound, the entire amp is suspended to eliminate vibration to the chassis, and it's now the same with two of them. I'd would pop the grille off (two tabs at the bottom of the cabinet) and tighten the screws on the speakers. Alot of times, there's one or two screws that aren't tight on new cabs. It happens...people make these things, and people make mistakes. Also, have you simply tried pushing on all the velcro tabs to make sure they're clicked in and tight? That could simply be it. Do that first.
  16. JeezyMcNuggles


    Feb 23, 2018
    Santa Maria, CA
    I suck, but nobody really notices
    The chassis on a v4b is suspended in the air (upside down actually) to eliminate vibrations to the components. It's not the amp.
  17. JeezyMcNuggles


    Feb 23, 2018
    Santa Maria, CA
    I suck, but nobody really notices
    Here you go bro 20200617_175214.jpg
    Wasnex likes this.
  18. Sgramza


    Oct 19, 2018
    Appreciate the input, but its not rattling when the head is on the floor next to the cab. Only when the head is sitting on top of the cab. Its definitely coming from inside the head. My guess is the design of the V4B reduces vibrations, but definitely doesnt eliminate them.
  19. JeezyMcNuggles


    Feb 23, 2018
    Santa Maria, CA
    I suck, but nobody really notices
    Well, it'd actually get far more vibrations on the floor than it would on your cab. The floor is taking the beating. Your cab is braced. Put your amp on top of your cab, but not in the footcups. See if it's the foot cups. Also, pop the grille off your amp. See if you can hear isolate the rattle if it is inside.
    Basslice likes this.
  20. Basslice

    Basslice Supporting Member

    May 11, 2008
    Western Massachusetts
    The same rattling on two different new heads is weird. Like really weird. Are you 100% sure it is coming from the head? I know you played it on the floor and it went away, but the amp is really heavy and when you take that weight off the cabinet you change things. It could still be the cab.

    Have you moved the rig around the room? When I play very loud in my basement, I can get all kinds of objects in the room to resonate (drives my spouse crazy when I do this).

    Can you describe the rattle?
    Wasnex, Aqualung60 and JeezyMcNuggles like this.
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