Question for Mesa D-180/bass 400 owners

Discussion in 'Amps and Cabs [BG]' started by N*Joy, Jun 23, 2003.

  1. N*Joy

    N*Joy Guest

    Nov 30, 2002
    Birmingham, UK
    I've just acquired a D-180 but I think that channel one isn't working, plugging into 1 does nothing until the gain on channel 2 is turned up. I'll probably just take it to a tech for this but I thought I'd run here for a few ideas.

    Plus, I seem to remember the pre-amp tubes being 3 12ax7's and 1 12au7 - is that right? If so which slot does the au7 go in?

    Thanks alot!
  2. Got my D-180 back in '83, it's a great amp, alot great tone.

    Vol/Input 1 is connected in series to Vol/Input 2 which is then connected in series to the Master. That is why you are not hearing anything plugging into Vol-1, got to add a little volume to Vol-2.

    Go the MESA site,, under "User Manuals" select D-180 and they will give a good run down on how to get a real nice clean sweet sound and two different ways of getting some cool crunch.

    I've got my D-180 and Acoustic 360 on loan to my son for some gigs in South Carolina. If I remember (?) correctly the preamp tubes are laid out as follows:

    AX7 AT7 AT7 AX7

    There are some adhesive stickers put on the floor of the amp noting the tube layout that MESA put in there. Sent an email to my kid to check the layout and email me back. Let you know as soon as I hear word.


  3. N*Joy

    N*Joy Guest

    Nov 30, 2002
    Birmingham, UK
    Thanks man, that's very helpful!
  4. Got an answer on the preamp tubes, sorry it took a couple days.

    As an aside, my son never got back to me by email, he got bit by a spider, had a reaction and is recovering, doing OK.

    Anyhow, did some digging and found my old manuals where I noted the original preamp tube layout as follows:

    12AX7 12AT7 12AT7 12AX7

    so I guessed right the first time.

    The placement may have changed with later models, maybe not, fire an email to Mesa with the serial number and may be able to tell you if they changed the values.

    Have fun with it, I'm trying to get mine back from my boy right now, but he's not wanting to give it up!

    John :cool:
  5. N*Joy

    N*Joy Guest

    Nov 30, 2002
    Birmingham, UK
    That's fantastic, thanks for getting back in touch on this one. Hope your son has a quick recovery - makes me glad there's nothing in our countryside of such a nature!