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Boogie 400 and 400+...Let's clear things up.

Discussion in 'Amps and Cabs [BG]' started by FireBug, Sep 29, 2005.


  1. FireBug

    FireBug

    Sep 18, 2005
    Houston
    I've already done a couple of TB searches on this, but still have a few questions.

    The 400 is best equipped with six 6550s
    The 400+ runs twelve 6L6s

    The 400 has a six band EQ
    The 400+ has a 7 band EQ

    The difference in power???
    Why would Mesa make the switch from only six 6550s to twelve 6L6s? Wouldn't this increase weight as well as reduce the reliability (in that one bad tube drags down the rest)?
    Is there some sonic difference in having more low-power tubes?
    Is it possible to replace the 6L6s in the 400+ with 6550s to get more power?
    Are the 6550s more expensive and do they not last as long?

    I am very confused. :confused:
     
  2. both have ~300 watts RMS output ( each 6550 = 50 watts, each 6L6 = 25 watts, roughly )

    There is no way i know that you can use 6550's in the 400+ i dont think it can be done
     
  3. In terms of reliability, the 400+ (can't speak to the 400) power tubes are paired. In the event that a tube should fail, the failed tube and its pair can be removed and the amp will continue to boogie albiet with reduced power.

    I can't really see the need for more power out of the 400+. It's got enough oomph to rock loud assuming it has a cab or 2 that can keep up.
     
  4. SoComSurfing

    SoComSurfing Mercedes Benz Superdome. S 127. R 22. S 12-13.

    Feb 15, 2002
    Mobile, Al
    I know in the Strategy 500 (and possibly the Strategy 400), the older ones, like mine, run 4 6550s and 8 6L6s. Mesa told me that towards the end of production of these amps Mesa switched to using only 6L6s, possibly around the same time as the 400/400+ switch, because the 6550s they were using were either getting harder to find or too expensive.
     
  5. tombowlus

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

    Apr 3, 2003
    North central Ohio
    Editor-in-Chief, Bass Gear Magazine
    My Strategy 400 (a 2-channel amp) can run either six 6L6's per side or four 6L6's and two EL34's per side, but no 6550's (and I have asked Boogie).

    It sounds like you have the differences down pretty well. My guess is, as stated above, that that the switch had a lot to do with Mesa Boogie's switch from a supplier of affordable 6550's to a similar supplier of 6L6's. My Bass 400 manual has "or 6L6's" written in a differnt ink right behind "6550's" on the spec sheet under "power tubes."

    FWIW, I have played a couple of 400+'s and one 400 (mine), and while I was not able to do a direct A/B, I was able to use similar instruments and similar cabs. To my ears, they did sound slightly different (and I prefer the Bass 400, though I could see someone else preferring the 400+).

    Do you have any remaining questions regarding the differences between the two? I'm no expert, but I'll help as I can...

    Tom.
     
  6. FireBug

    FireBug

    Sep 18, 2005
    Houston
    I called Mesa and asked why they used twelve 6L6s instead of six 6550s and they said because the 400+ is twice as powerful. Apparently you can change out the 6L6s in the 400+ with 6550s, but with no change in output power.

    This is very different from what I've been reading on TB.
    Hmm...
     
  7. tombowlus

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

    Apr 3, 2003
    North central Ohio
    Editor-in-Chief, Bass Gear Magazine
    If you used six 6L6's in a Bass 400, it would be less powerful (close to 1/2) than a 400+ with twelve 6L6's. But, a 400 with six 6550's or KT-88's will be close to the same power as a 400+ with twelve 6L6's (though not quite as powerful, as the transformers don't appear to be up to pushing every last watt out of six 6550's). It is my understanding that you absolutely cannot put twelve 6550's into a 400+.

    Tom.
     
  8. SoComSurfing

    SoComSurfing Mercedes Benz Superdome. S 127. R 22. S 12-13.

    Feb 15, 2002
    Mobile, Al
    :eek:
    12 6550s!! Wow, that's a happy thought! Maybe some day...
    :hyper: :hyper: :hyper:
     
  9. could push 600 watts . . . if you changed the transformers obviously, very expensive retube . . .
     
  10. metron

    metron Fluffy does not agree

    Sep 12, 2003
    Lakewood Colorado
    Twice as powerful as the 400? Either there is a misunderstanding with what they said or they are saying things that are not true. 6L6s are good for about 25 W each and 6550s 50 W each. Twelve 6L6 or six 6550 will make for an amp with about 300W RMS. That statement would make sense if you replace 400 with 6550. :confused:
     
  11. TrooperFarva

    TrooperFarva

    Nov 25, 2004
    New City, NY
    Early 400+s still have a 6 band EQ
     
  12. Tash

    Tash

    Feb 13, 2005
    Bel Air Maryland
    Mesa advertises the 400+ as a 500 watt amp. They are kind of vauge about the fact that those are 500 peak watts, not RMS. So the 400+ has more power at peak than the 400. Which I guess makes it twice as powerful through some kind of math.
     
  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
    No offense to Mesa, but that's all bad math. Niether amp puts out more than 300 watts. The transformers just aren't up to it. My guess is that both are in the mid to high 200's as far as actual wattage goes. BUT, in my opinion, this is a very good sounding amp (in either flavor), and I think of it as the tone being the design target, as opposed to maximum power output. The Bass 400/400+ is a very versatile amp and tonally beautiful amp, though I do think that the power ratings have been both overstated and misunderstood.

    Tom.
     
  14. BurningSkies

    BurningSkies CRAZY BALDHEAD

    Feb 20, 2005
    Seweracuse, NY
    There's some bad mis-information here. You can NOT put the 6550's in the 400+. It doesn't work that way. You WILL fry your amp in doing so.

    Don't you think that if it was true, every power hungry bass player who owns a 400+ would be running their 400+ that way, getting 600w?


    If you try, please take pictures and post them.
     
  15. tombowlus

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

    Apr 3, 2003
    North central Ohio
    Editor-in-Chief, Bass Gear Magazine
    And be sure to notify your local fire department! :eek:
     
  16. FireBug

    FireBug

    Sep 18, 2005
    Houston
  17. There are 4 tubes in that amp and it costs $10,000. Those tubes are probably mega expensive.
     
  18. jvb

    jvb

    Jul 11, 2005
    Canberra, Australia

    thetubestore.com has Shuguang 813s for $43.95 ea.
     
  19. There are a lot of 400s using 6x6l6 so the 400+ would likely be twice as powerful as that, but the 400+ is not twice as powerful as a 400 with 6550s.

    There's no point in putting 6550s in a 400+ to get more power because the power supply won't allow it anyway. The amp can only swing the power supply voltage so changing to 6550s won't increas power. The other issue is that 6550s draw twice as much heater current as 6l6s. I doubt that the filament winding on the transformer could reliably deliver that much extra current.
     
  20. BurningSkies

    BurningSkies CRAZY BALDHEAD

    Feb 20, 2005
    Seweracuse, NY
    I don't know where Phil Jones gets his branded tubes, but its entirely possible that they're not mega-expensive tubes...His stuff is mega expensive anyway with or without tubes. That amp is on the top of the list for when I win the lottery.