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Tube Question??

Discussion in 'Amps and Cabs [BG]' started by reasonbass, Jul 27, 2003.

  1. Jul 27, 2003 #1
    reasonbass

    reasonbass

    Dec 6, 2002
    Miami, Florida
    Hi, I just got a brand new Mesa 400+ and when I turn it on stand by the tubes glow normal. But when I take the stand by off the tubes start to glow with a blueish tint. I think I read somewhere that this was bad. So I was wondering if anyone can help me out.

    thanks
     
  2. Jul 27, 2003 #2
    JonB

    JonB

    May 27, 2003
    Indianapolis
    This sounds pretty normal.
    When you have the switch on standby, only the filaments are being heated with no other voltages in the tube. Put the switch in normal position, and B+ voltage, probably 400 to 500 volts is being applied to the plates. This causes some ionization of trace amounts of gas in the tube, giving a faint blue glow. Sometimes, it is just visible on the inside of the plate, and sometimes the whole tube has a violet glow, but will still be a good tube. It's bad if it has a bright blueish-pink glow, or if the plate(s) (the big grey cylinder-thing) are glowing red.
    If you have any doubts, have a technician check the tubes and the bias voltage to make sure you're not damaging the amp.
    You might want to get a bias meter so you can check this yourself. It comes in handy when you retube, too.
    Hope this helps.
     
  3. Jul 28, 2003 #3
    Zentner

    Zentner

    May 5, 2003
    Edmonton, Alberta, Canada
    My 400+ does the same thing.

    I just accept it as looking incredably cool. my tone is better than ever, and all my power is there, so i can't complain. I'm pretty sure the blue glow is natural.

    Doesn't it look like the back of your amp is on fire?!!?! Looks sooooo cool!

    ~Zentner
     
  4. Jul 28, 2003 #4
    reasonbass

    reasonbass

    Dec 6, 2002
    Miami, Florida
    Yeah it does look cool..lol..Man I havent had time to crank it yet because everything in my house shakes and rattles. I had paintings falling off the walls! I love it.:D
     
  5. Jul 28, 2003 #5
    erikwhitton

    erikwhitton Guest

    Sep 20, 2002
    Portland, ME USA
    YEAH!

    When I first got my 400+ i turned it to about 5 and felt like i could shatter every window in my building if i went too much higher!
     
  6. Jul 28, 2003 #6
    reasonbass

    reasonbass

    Dec 6, 2002
    Miami, Florida
    Dudes, I have another question here it goes:

    Can u use the slave out as a tuner out? I tried it and it worked. But I don't know if it will damage the amp in any way. I only tried it for a little bit.

    thanks
    Rodrigo
     
  7. Jul 28, 2003 #7
    Rockbobmel

    Rockbobmel

    Feb 14, 2002
    Greenfield, MA(Nowheres'ville)
    Check with your owners manual. I can't find mine. I use a tuner before the amp anyway. They usually have mute switches for silent operation.
     
  8. Jul 28, 2003 #8
    ampegsvtca

    ampegsvtca

    Dec 15, 2002
    Airdrie, Alberta. Canada
    The GE 6550's in my vintage svt glow blue, looks cool and sounds great. I have even had some of the drive tubes glow blue (Brimar and Tung Sol black plate 12BH7's).