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Mesa 400/400+

Discussion in 'Amps and Cabs [BG]' started by Ripper75, Aug 15, 2005.


  1. Ripper75

    Ripper75

    Aug 8, 2005
    Boise, ID.
    What is the difference between the 400 and 400+?
     
  2. they are different amps

    different pre sections and different power sections

    most notably the 400 uses 6x6550's (Can also use 6L6's i think, but that only gives half the power of the 6550's)

    the 400+ uses 12 6L6's in the power section

    either way, they are both about 300 watts output ( the 400 is only about 150 watt output with 6L6's instead of 6550's )

    even at 300 watts they are still loud beasts, as most 300 watt tube heads are
     
  3. Ripper75

    Ripper75

    Aug 8, 2005
    Boise, ID.
    So are they equal in sound?
     
  4. tombowlus

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

    Apr 3, 2003
    North central Ohio
    Editor-in-Chief, Bass Gear Magazine
    The two are in the same general ballpark, tone-wise. In addition to the power section differences, the graphic EQ on the 400 is a six band, while the 400+ boasts a seven band. Other than that, though, I think the preamp section is quite similar. Nevertheless, the 400 which I recently picked up does sound a bit different (and somewhat better, IMHO) than the 400+'s that I have tried. I am running six 6L6's, but I am thinking about adding bias trim pots and switching to 6550's.

    Tom.
     
  5. They are equal in power output is what i was getting at, thats about all i know
     
  6. danomite64

    danomite64

    Nov 16, 2004
    Tampa, Florida
    Mesa told me that I could use either 6L6 or 6550 tubes without rebiasing the amp. 6L6's produce about 190 watts, and 6550's produce 240. Also, early 400+ amps have 6 band graphinc eq's just like the 400 does. I have an '86 400 and it sounds very close to the '95 400+ I used to have.
     
  7. mgmadian

    mgmadian

    Feb 4, 2002
    Austin, TX
    IIRC, only the 400+ has a 2-ohm output.
     
  8. tombowlus

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

    Apr 3, 2003
    North central Ohio
    Editor-in-Chief, Bass Gear Magazine
    I was told the same thing, but after talking to a number of knowledgable tube techs, I think that I can get the most out of my tubes if I install bias trim pots.