Ampeg V4B with GK RBH Cab

Discussion in 'Amps and Cabs [BG]' started by Diegol, Jan 14, 2013.

  1. Diegol


    Jan 14, 2011

    Hope someone could help. Is there any other way of connecting my amp through this cabinet rather than the normal 1/4 input?

    Maybe something that gives me more control, headroom.. i don't know. Just experimenting and I don't want to blow anything

  2. JimmyM


    Apr 11, 2005
    Apopka, FL
    Endorsing: Ampeg Amps, EMG Pickups
    Why do you need another way?
  3. The amp provides the "headroom".
  4. BassmanPaul

    BassmanPaul Gold Supporting Member

    Aug 25, 2007
    Toronto Ontario Canada
    No. It's a 100W amp and that's all she wrote.
  5. GreaserMatt


    Sep 4, 2004
    Seattle, WA
    What a great amp tp own though! Pics please... LOL
  6. Diegol


    Jan 14, 2011

    Its a late V4B... I changed the plate just for looks so now it has those early V4B plates they sell at flip top. The grill was all torn so i removed it and hopefully would get one soon.

    I really love the amp but lately i hear it distorting too early. Don't really know what to do for more headroom. Maybe its the speakers at some point
  7. How early does it break up? 11:30 to 12:00 is about the max clean with a little bite.
    You could have a weak preamp tube or output tubes getting weak or drifted too far from the idle bias point.
  8. Diegol


    Jan 14, 2011

    its breaking at 10... too early I think... Im no amp expert and sadly, here in Chile, the options on finding someone who know about this is limited...
  9. !0:00 is too early. Is this the newer master volume model? Both channels break up at same point?
  10. Diegol


    Jan 14, 2011
    no master volume... yes, same for both channees
  11. So lets try an experiment. No bass plugged into the amp, turn the volume up all the way (speaker cab connected!). If you hear a hum adjust the "Hum Balance" control on the rear of the amp for the least hum. If the hum can not be made barely heard the power supply caps may be weak and that will cause the early distortion. If the hum started out bad and now is quiet try the amp again before looking for weak tubes.
  12. JimmyM


    Apr 11, 2005
    Apopka, FL
    Endorsing: Ampeg Amps, EMG Pickups
    10:00 isn't necessarily too early if you have a hot bass. However, most of them start breaking up around the 11:00-12:00 point.
  13. Yes this could be true. With my V4B I used a 12AU7 for channel one to make it friendly for my active 4 string. Channel two was standard for the passive 5 string.
  14. anderbass


    Dec 20, 2005
    Phoenix. Az.
    The lower-register/E-string notes start breaking up around 10 o'clock on my V4 too.
  15. Sounds like adding a bias adjustment pot would be in order for newer production tubes. Easier than than having to replace resistors every time there is a bias drift. Granted if the power supply and bias caps are up to spec.
  16. Diegol


    Jan 14, 2011
    Hey BString

    Tried your experiment. It turns out, the amp already had a bit of hum (don't really know how to explain if its normal or not) but turning the balance just made it worst.. so..
  17. If you can not get the hum out with the balance control (turn it both ways to where the hum is the least or gone) you may have a bad tube or weak filter caps.