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400+ Noisy

Discussion in 'Amps and Cabs [BG]' started by Hounddog, Sep 6, 2005.


  1. Hounddog

    Hounddog

    Dec 2, 2004
    Southern, Illinois
    Sadowsky Featured Artist
    I bought a 400+ A while back it is an awesome amp. It had never been retubed and it is about 15 years old. I bought a total retube kit. It sounds better than ever when playing loud but after the retube it is noisy, like static and is real noticable when not playing or playing at low volume. Sometimes it gets louder. I cleaned the socket connections with contact cleaner. And the new tubes seemed to fit good and snug. It started about a day after the retube. I know it is most likely something simple but I cant put pin point the problem. Can you tube amp guys help me out. Thanks,

    Mike
     
  2. Plain Old Me

    Plain Old Me

    Dec 14, 2004
    It could be one of a thousand things. Bring it into a tech. And I hope you didn't get the Mesa tubes... FYI Mesa tubes are just normal tubes marked way up in price, and in my opinion they don't even sound as good as most other tubes.
     
  3. Hounddog

    Hounddog

    Dec 2, 2004
    Southern, Illinois
    Sadowsky Featured Artist
    I got JJ tubes From Bob at Eurotubes. The tone is more than awesome. I cant say enough good about the tone. but I have this hissing or static noise now. It gets louder at times and then calms down for a little while. It could just be coincedence but it never did that befor I put new tubes in it.
     
  4. Plain Old Me

    Plain Old Me

    Dec 14, 2004
    Sounds like a bad filter cap possibly. I got one of those when I first picked up my Mesa 400+ which had just been retubed. However, with a tube amp it is very hard to pinpoint a problem...
     
  5. BurningSkies

    BurningSkies CRAZY BALDHEAD

    Feb 20, 2005
    Seweracuse, NY
    It could be a filter cap, or a bad tube can also 'crackle'. Bob's very good but sometimes a bad tube does slip through.

    Before you send it out for work, try the old tubes in it and see if it still does it. If not, then you know it's a bad tube.
     
  6. Hounddog

    Hounddog

    Dec 2, 2004
    Southern, Illinois
    Sadowsky Featured Artist
    Thanks everyone. I will let you know what I find.

    Mike
     
  7. Folmeister

    Folmeister Knowledge is Good - Emile Faber Supporting Member

    May 7, 2003
    Tomball, Texas
    Mine did that with a bad tube.
     
  8. Hounddog

    Hounddog

    Dec 2, 2004
    Southern, Illinois
    Sadowsky Featured Artist
    Is it possible to pull the tubes out one at a time while the amp is on ? Or would that damage the amp ? What is the easiest way to find a bad tube ?

    Thanks
     
  9. Plain Old Me

    Plain Old Me

    Dec 14, 2004
    It would burn your fingers... and could kill you due to the voltages being applied... and you need to take out certain pairs at a time to be able to take tubes out at all.
     
  10. BurningSkies

    BurningSkies CRAZY BALDHEAD

    Feb 20, 2005
    Seweracuse, NY
  11. Hounddog

    Hounddog

    Dec 2, 2004
    Southern, Illinois
    Sadowsky Featured Artist
    I finally found the problem. I first went through all power tube sockets tightened them up with a safety pin and cleaned them with contact cleaner. That didnt help. I then put my old Power Tubes in and that didnt help. I put my new tubes back in and started looking at the Preamp section.I then Went through my Preamp tube sockets with contact cleaner and an needle and tightened the sockets put my old Preamp Tubes in and the noise went away. I went through one at a time placing the amp in standby waiting about 30 seconds, shutting the amp off replacing one preamp tube,Turning the amp on waiting 30 seconds or so and flipping the standby switch to on. When I got all the new tubes in there was no noise. I guess it was a loose or dirty socket connection. So I am back in love with my new JJ tubes from EuroTubes.

    MY APOLOGIES TO BOB AT EUROTUBES FOR EVEN MENTIONING WHERE I BOUGHT THE TUBES. SORRY BOB THE TUBES ARE AS AWESOME AS YOU SAID THEY WOULD BE.

    Mike
     
  12. anyonefortennis

    anyonefortennis Supporting Member

    Jun 28, 2005
    Lincoln, NE

    NO NO NO NO!!!!!!


    Tube amps carry a LOT of voltage through those tubes and caps(450volts or so. 4x a regular power outlet). Caps may even hold voltage for days!!! Never ever go near the tubes of an amp if you don't know what you are doing.

    If you are lucky, you'll have an irregular heartbeat for a couple of days and that's it, but most likely you'll fry your brains.

    I'm talking from experience here folks, an idiot spilled a drink on an old marshall I was playing and a twisting a volume knob almost killed me. Stay away from them tubes!
     
  13. tombowlus

    tombowlus If it sounds good, it is good Gold Supporting Member

    Apr 3, 2003
    North central Ohio
    Editor-in-Chief, Bass Gear Magazine
    Glad to hear that it all worked out!

    Tom.
     
  14. Hounddog

    Hounddog

    Dec 2, 2004
    Southern, Illinois
    Sadowsky Featured Artist
    I didnt do anything with the Amp plugged in. I didnt think it was wise Thats why I asked. I have enough sense not to touch anything but the glass tube with a towel so I wouldnt get burnt. And glass is an insulator. I wasnt worried about getting shocked I was worried about what it would do to the amp to remove a tube. Anyway I got the problem fixed now. I am an electrician at a Power Plant. I know how to keep from getting shocked and know all about capacitors but I dont know much about tube amps. I have been hit by 480V a couple of times. It hurts very bad.

    Mike
     
  15. anyonefortennis

    anyonefortennis Supporting Member

    Jun 28, 2005
    Lincoln, NE
    YOu probably know more than I do then about the hazards of electricity :).

    Pulling tubes really depends on the amp. Some can handle it better than others and it's USUALLY safe as long as it's not for a long period of time.

    Anyways, glad you got the amp figured out, the 400+ is an absolute workhorse.
     
  16. Hounddog

    Hounddog

    Dec 2, 2004
    Southern, Illinois
    Sadowsky Featured Artist
    Thanks to everyone for your help.


    anyonefortennis,

    I see you have a Ric. I had a maple 4001 for years. I bought a cirrus and love it but I sure wish I had my old Ric back.

    Mike