Majior ground HUM in my Studio!! Bruno eats Spikes!

Discussion in 'Amps and Cabs' started by Mad John, Mar 6, 2008.

  1. Mad John

    Mad John Member

    Messages:
    622
    Joined:
    Jul 18, 2007
    Hi everyone,

    First off, I have to give a shout out to Lou V, for whom I just purchased this beautiful Tony Bruno Underground 30. Thank you Lou, your the best! Lou even threw in 3 extra NOS tubes, so that I might have some extra tonal variety out of the amp....you are so awesome Lou!! :AOK

    Ok, now the problem. I just had a new studio built for me that took over 4 years, but that is another story...lol.

    There is major HUM coming out of the Bruno amp. It is a terrible POWER PLANT ground HUM (really noisy with high end spike.) I know it is the ground, for when I touch the metal tuners, it basically quiets down to a normal "AMP ON" sound.

    Can anyone suggest what device I might use? My home was already checked several times for grounding hums and spikes and no one could fine anything and yet, when the dimmers are on up stairs, the ground gets so loud as to be unplayable!

    I saw this at American Musical supply - http://www.americanmusical.com/ProductImages/Large/p26097.jpg
    [​IMG]


    Any suggestions would be appreciated!

    Thanks,
    JT
     
  2. Mad John

    Mad John Member

    Messages:
    622
    Joined:
    Jul 18, 2007
  3. Jason_86_951

    Jason_86_951 Supporting Member

    Messages:
    2,033
    Joined:
    Jan 11, 2005
    Location:
    Selah, WA
    A bad power tube can also cause that type of hum.

    Has you checked your bias or tried different tubes? Does the ground switch change anything?
     
  4. quinnamps

    quinnamps Member

    Messages:
    1,224
    Joined:
    Jul 5, 2007
    Location:
    Phoenix, AZ.
    Try swapping tubes. Get a known good pre amp and trade it out with V1. If no joy put the old tube back in the V1 slot and take your known good tube over to V2. Work your way down until you either get rid of the hum or get to the power tubes. When you get there same thing. If you have a set of known good tube drop them in and see if you have joy.
    If you cannot narrow it down to a bad tube looks like it will need some TLC.
     
  5. plygtar

    plygtar Member

    Messages:
    119
    Joined:
    Mar 12, 2007
    Location:
    West of Phila, PA
    Get yourself an Ebtech Hum X device and plug your amp's power cord into it. Check out www.ebtechaudio.com.
     
  6. Mad John

    Mad John Member

    Messages:
    622
    Joined:
    Jul 18, 2007
    Hello Jason!

    No, I just got the amp yesterday. My 5 watt Bad Cat does the same thing. I tried the ground switch, but there was no difference.

    However when I touch any metal (including the strings) on the guitar, the noise stops.

    I need something for the amps to plug into, because there is nothing I can get the electricians to do, that they have not already tried.
     
  7. teleblaster

    teleblaster Member

    Messages:
    1,299
    Joined:
    Nov 18, 2005
    Location:
    colorado
    If it s New why not just send it back. Or, call and ask the builder. A brand new amp should be perfect right out of the box. Tubes and all.
     
  8. Jason_86_951

    Jason_86_951 Supporting Member

    Messages:
    2,033
    Joined:
    Jan 11, 2005
    Location:
    Selah, WA
    Run around your house and start turning off devices one by one, see if it's something in your home causing the hum. Or go to your breaker box and turn off circuits one by one.

    If grounding the strings cause it to stop completely, it's not the amp. It's something in your power.
     
  9. quinnamps

    quinnamps Member

    Messages:
    1,224
    Joined:
    Jul 5, 2007
    Location:
    Phoenix, AZ.
    You mention this and other amps having the same trouble so if the Bruno isn't an isolated problem amp then indeed you have house issues.
     
  10. Mad John

    Mad John Member

    Messages:
    622
    Joined:
    Jul 18, 2007
    Thanks guys for all the great responses! The amp is new TO ME, but is used (I got it from Lou V) The amp is 2 years old and as far as I can tell in mint condition! :) It sounds like the best amp that I have ever heard...I just can't take my hands away from the strings, with out a huge ground HUM!

    Yeah, the problem is some wild ground hum that can't be tamed, even with all the lights and units off in the house.

    Thank you plygtar, I will look into the Ebtechs.
     
  11. Tag

    Tag Gold Supporting Member

    Messages:
    32,294
    Joined:
    Jan 5, 2002
    Location:
    New Jersey
    Thats not a probelm with the Bruno obviously. You should go advanced and change the title of the thread.
     
  12. riffmeister

    riffmeister Gold Supporting Member

    Messages:
    16,506
    Joined:
    Jan 4, 2003
    Location:
    near Philly
    Agreed, it's a problem with the wiring in the house.
     
  13. Lyle Caldwell

    Lyle Caldwell Member

    Messages:
    545
    Joined:
    Jan 8, 2005
    Location:
    Memphis
    Ebtechs are really an emergency fix - they do change the sound.

    You need to ensure the outlets are properly grounded, that you have good power cables, and good guitar cables.
     
  14. nek

    nek Member

    Messages:
    1,440
    Joined:
    Jan 5, 2002
    Location:
    Portland, OR
    It happend to me when I got cable TV installed. The remote cable grounding caused a loop. A quick check can verify an issue like this. Get one of those 3 to 2 prong adaptors. Do not connect the green ground wire. If the hum goes away, its something like this.
     
  15. Tag

    Tag Gold Supporting Member

    Messages:
    32,294
    Joined:
    Jan 5, 2002
    Location:
    New Jersey
    Yea, and the title of the thread makes it look like ites a Bruno problem (which its not) and a "new" Bruno. (Which its not.)

    :)
     
  16. Markgtr

    Markgtr Member

    Messages:
    44
    Joined:
    Feb 13, 2008
    Ummm, if the noise goes away when you touch the metal parts of your guitar, it's the guitar picking up noise. Check the amp with nothing plugged into it, if it sounds fine then it ain't the amp.:)
     
  17. Mad John

    Mad John Member

    Messages:
    622
    Joined:
    Jul 18, 2007
    Thanks everyone. Sorry to mislead with the title. To clarify:

    The Bruno Underground 30 is the sweetest amp that I have ever heard. I use Zaolla and Evidence cables, Lindy Fralin PUs. I tried 2 Strats, I Tele and My 1954 Gibson 175 w/original P 90s. They all sounded gourgous and the ground HUM was out of control. The ground switch on the Bruno seems to make no change.

    The point I was making about touching a screw on the top of the amp, when the HUM would die down, is the same with touching the strings or any metal on the guitar...it is a ground issue, not a PU issue.

    I need to know if there is a way (since a human hand seems to tame the noise) that some device might be utilized, that does not suck tone and can easily cut this buzz and HUM the way my hand does. Speaking of which, what makes playing the amp in this condition so lousy, is when you play a chord or whatever and lift your hands off the strings to reach another position, the ground sound SWELLS.

    I can not record with all this noise, yet if I play with one hand, while touching a metal part of the amp head, it is as quiet as a mouse and ready for anything. Again this is no fault of the Bruno...the amp is blowing me away with all the tone that I am hearing, even with this problem.

    I will try anything to get this HUM out, so any more suggestions out there?

    Thank you guys!
     
  18. Randy

    Randy Member

    Messages:
    3,885
    Joined:
    Sep 9, 2002
    Location:
    CT
    As was already stated, if the amp doesn't hum when nothing's plugged into it or when your guitar is turned off, it's the guitar introducing noise.

    All the guitars you mentioned trying have single coil pickups. Try a humbucker or noisless single coil and get back to us. Do you have fluorescent lights in the room? What kind of shielding do your guitars have?
     
  19. DavidH

    DavidH Member

    Messages:
    2,365
    Joined:
    Sep 25, 2006
    Um,that wasn't very clarifying TBH.Does it hum with no instument cable plugged in?

    Hum dying when you touch the chassis(or the guitar strings) is normal and does not indicate a grounding issue.Sounds like we might be just talking about the guitar picking up noise within the house,you mentioned dimmers,if you've got low voltage lighting with dimmers,those things are hella noisy.Leave the guitar plugged in,with the amp on and then go to the fuse box and switch off all other circuits in the house,if it quietens down then switch them back on one at a time to see which one is the culprit.It'll be the lights though,i bet.
     
  20. landru64

    landru64 Member

    Messages:
    2,418
    Joined:
    Mar 17, 2004
    Location:
    Los Angeles area
    what kind of guitar and is it shielded?
     

Share This Page