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New preamp tubes in my Mesa 400+...

Discussion in 'Amps and Cabs [BG]' started by As the sun sets, Apr 1, 2003.


  1. As the sun sets

    As the sun sets Guest

    Dec 10, 2002
    N. Easton, MA
    Hi folks. My birthday is coming up on Sunday (April 6th) - the big nineteen. Woo! Anyways, my girlfriend said that she would get me basically whatever I wanted... so I am going to be getting some new preamp tubes for my 400+. I had her order five Sovtek 12AX7LPS tubes, and one JAN-Philips 12AU7. I've heard the 12AU7 will sound good in the V1 position - can anyone put any truth to this? I've heard some good things about these new Sovteks - can anyone put any truth to that? On another note - I should be getting my Geddy Lee jazz bass by the end of this week :)

    Thanks for any info, folks! :D
     
  2. stevekim

    stevekim

    Feb 11, 2000
    los angeles, ca
    i don't know but i've always had good luck with mesa preamps. they may not be the sweetest sounding preamps out there but i like the fact that my amp was designed with these tubes in mind. that said, it doesn't hurt to experiment.

    someone correct me if i'm wrong but aren't mesa tubes made by sovtek?

    steve
     
  3. Benjamin Strange

    Benjamin Strange Commercial User

    Dec 25, 2002
    New Orleans, LA
    Owner / Tech: Strange Guitarworks
    Mesa buys tubes from everywhere. It's how they test them that matters (I hear they sell off thier reject tubes to Groove Tubes and Fender). So, yes, some Mesa tubes are Sovteks.

    I use Mesa SP12ax7s in all my preamp spots (that's 11 tubes. Yikes!). They are much quieter than normal 12ax7s, and sound pretty good. I don't have alot of experience trying other "brands" because of the cost involved. Maybe one day when I have nothing better to do...
     
  4. Benjamin Strange

    Benjamin Strange Commercial User

    Dec 25, 2002
    New Orleans, LA
    Owner / Tech: Strange Guitarworks
    Happy birthday, by the way!:D
     
  5. Happy B day pal.
    I would get the 12ax7EV (electrovoice) I once put 4 sets of Sovtek pre tubes you mentioned and all of them blew out! I know they had some trouble with the first batches and may have improved them by now. The 400+ did not like those tubes!!!!
    Better check before you get them. I can tell the Ev's I have in my 400+ are shaaaaweeet. good luck!
     
  6. Chuck M

    Chuck M Supporting Member

    May 2, 2000
    San Antonio, Texas
    The Sovtek 12AX7LPS is a good sounding tube, however, they are very prone to being microphonic. At one time the reject rate was about 50%. Hopefully they have improved the QC at the factory.

    Chuck
     
  7. As the sun sets

    As the sun sets Guest

    Dec 10, 2002
    N. Easton, MA
    Thanks for the responses, guys. Hopefully the 12AX7LPS' won't blow out or be microphonic when I get them! They should be here tomorrow, and I have rehearsal tomorrow night so I'll let you know how it goes with them. Anyone ever tried putting one of the 12AU7's in the V1 position?
     
  8. How do you label the positions in the 400+, and what are the difference between the different positions in it. I have been wondering that when I looked inside my 400+ for som cleaning.
     
  9. My 400+ has a static type sound that is worst just after I turn it on, and pretty much goes away after I play it a few minutes. It is just as loud with the input controls off.

    Is this preamp tubes going bad ?

    Aloha,

    Jonathan
     
  10. Benjamin Strange

    Benjamin Strange Commercial User

    Dec 25, 2002
    New Orleans, LA
    Owner / Tech: Strange Guitarworks
    The different positions are usually different stages in the preamp. Probably one tube for volume one, one for volume two, etc. There is probably a tube chart in the manual.

    Jonathan, it sounds like you've got a tube going bad. Change the offending tubes(s) and you should be ok.
     
  11. Try and find some NOS (New Old Stock) tubes.