mesa 400+ retube question...

Discussion in 'Amps and Cabs [BG]' started by thetaurus, Sep 15, 2003.

  1. thetaurus


    May 28, 2002
    Muncy, PA
    so as you know, i bought a used mesa 400+. when i recieved it in the mail, one of the tubes didn't light up like the others. i'm assuming it was blown, so i took it and its match out. it wasn't a mesa labelled was a sovtek. anyway...the sound wasn't good at all. i couldn't get any kind of close to a clean tone. the amp is a 95, and i'm assuming all the tubes in it are stock. so i ordered some jj6l6gc's and jj 12ax7's that i just got today. question is this: since mesa amps have a fixed bias, am i alright with just putting the new tubes in myself? or should i take the amp to a tech to have it checked out? nothing seems to be wrong with it, other than the tubes sound bad because they're so old. everything seems to be solid. will it be alright to just install the new ones myself?

    the reason i ask, is because i don't want to spend too much money here (i haven't deciced if i'm keeping it yet), and the closest certified tech is about an hour and a half away.
  2. If u bought them of Lord Valve, or Bob at Eruotubes. Just pop em in dude, Just loosen up those bear trap things, and wiggle the old tubes out, and put the new ones. Thats what I did. And I had no problems.
  3. ANY time you replace power tubes, it's tech time. I don't care what Mesa says; they're selling tubes, NOT repairing amplifiers. You might have a problem with the socket and it wasn't a bad tube after all. A tech could catch that quickly and fix it before it causes other problems and expensive repairs. A retube it a GREAT time to get an overall check of your amp's health for a minimum of time and money.

    Besides, just because you can't see a tube "light up" doesn't mean it's not working. The "light" is only the heater filament, and sometimes it's simply not visible, but that doesn't mean that the tube is bad.