Discussion in 'Amps and Cabs [BG]' started by alan_hill, Jan 7, 2009.

  1. alan_hill


    Nov 1, 2008
    So I've enquired about the B-15 and a few other amps and now I'd like a few words from the wise about the B-12.

    Thanks in advance.

  2. Vintage-Blue

    Vintage-Blue Gold Supporting Member Commercial User

    Feb 13, 2008
    Cincinnati, OH
    Owner, Vintage Blue (repro cabinets)
    Amplifier-wise the B15 and the B12 are identical. Cabinet-wise they're quite different. The B12 ends up being much lighter and easier to transport. It probably won't go as low as a B15 but it can still sound pretty good. I think the B12 is a very under-appreciated rig!
    BassBeginer64 likes this.
  3. 62bass

    62bass Guest

    Apr 3, 2005
    I've used both for recording and the B 12 sounds better.
    shadven and JeezyMcNuggles like this.
  4. 57pbass

    57pbass Supporting Member

    Aug 1, 2004
    Bayside, New York
    I have a B 12 and I installed an EV speaker.. its a great amp and you can really drive the tubes w/o the high volume levels.....natural tube distortion is a thing of beauty...
  5. jgsbass


    May 28, 2003
    Floral Park, NY
    There was something about the B12's cabinet. I used the cab with a power amp ( and a MXR line driver!) for rehearsals and the cab handled the extra power real well and this amp shook the loft. Not very portable because of the weight but I think thats part of the secret to that sound. No panel flexing in those cabinets.
  6. Tom Howland

    Tom Howland Supporting Member

    Feb 11, 2003
    I believe the B-12 was 22-25 watts.
    And the B-15 was 30-35 watts.

    The B-12 was made to go with the Ampeg Baby Bass.
    And the B-15 for electric basses.

    I recorded with a B-12 for years.
    Used a B-15 " live".

    Both sound great.
  7. biobass

    biobass Supporting Member

    Sep 16, 2007
    Princeton NJ area
    I have the SB-12 (String Bass) which was designed for the Ampeg Baby bass, and was rated at 22-25 watts. Very nice sounding if rather quiet by today's standards. Mojo-man, I think you may be confusing the SB-12 with the B-12.

  8. nysbob


    Sep 14, 2003
    Cincinnati OH
    I don't know what the difference between a B12 and an SB12 is, if there is any...

    I have an SB12 and it's been my studio staple of late.

    Sounds fantastic. :cool:
    SirMjac28 likes this.
  9. alan_hill


    Nov 1, 2008
    The amp I have in mind is a B-12XT? Any ideas?
  10. bassvi


    Jul 12, 2005
    That is a cool amp. My brother had a similar fliptop in the early 70's with 4x12's and he used it for guitar. I got to keep the cabinet when the amp blew. It sounded great for bass. Wish I still had it!
  11. MLChief


    Mar 15, 2011
    Central Florida
    Having owned one, I can tell you a better bass amp has never been made. Nearly every recording studio has one.
    Wish I still had one. It is 25 butt kickin watts.
  12. My very first amp was a shiny new SB12, I wish to hell I still had it.
    spankdaplank likes this.
  13. coreyfyfe

    coreyfyfe Supporting Member

    Nov 19, 2007
    boston, ma
    The B12 was the B15 amp on a 12" cabinet, so same wattage. There was also the SB12 which was smaller with a lower power amp.
  14. coreyfyfe

    coreyfyfe Supporting Member

    Nov 19, 2007
    boston, ma
    There's some info in the portaflex wiki on the various models including the B12XT. If you follow through the links on the side there you can find all the old sales lit, schematics, etc, if you want to check them out.
  15. There's a guitar store in Eugene Or. named MacKenzie music, that a few years ago had half a dozen of the oddball portaflexs'. Including the B12XT and others. They were there for several yrs., reading this thread I checked and they had all been sold.
  16. Tom Howland

    Tom Howland Supporting Member

    Feb 11, 2003
    Can someone help....please. I always thought the B12 was 22-25 watts. The B15N 35 watts. The B15S 60 watts.
  17. Matt O

    Matt O

    Feb 19, 2013
    The Mitten
    You are spot on.

    I'm thinking that B-12 and SB-12 are getting mixed up in the thread and there is some general misinformation, too.

    SB-12 is a lower wattage flip top for bass ~22 watts. It's not a B15 head on a smaller cab. Totally different. Single channel, even. SB-12 output transformer is much smaller than a B-15, so much so it resides inside the cage with the tubes. There may be similarities in design but they really are two different animals.

    B-12 and its X variants is a guitar amp.

    I think OP was meaning to ask about SB-12 and confusion set in.

    I've owned an SB-12, best amp for recording I've heard to date. Never should have sold it.
    Last edited: Apr 30, 2016
  18. coreyfyfe

    coreyfyfe Supporting Member

    Nov 19, 2007
    boston, ma
    Not quite, the B15 and B12 were the same amp, different cab. The B15S was the higher power version with a 12AX7 preamp, 7027A power amp. The SB12 is the lower power variant with 12AX7 pre/PI and 7868 power tubes. There was also the B18/B15ND (dual cab)/B15NC (column) variants which used a 6SL7 preamp but a 7199/7027A power amp and were also 50 watts. You can see all of the schematics in the wiki, the B12 and B15 share a schematic as you can see below:

  19. 40Hz

    40Hz Supporting Member

    May 24, 2006
    You can't go wrong with an old Ampeg fliptop. I have a late '60s B-15N, and I've played the B-12 as well as the SB-12. They're all beautiful sounding amps. If you are lucky enough to find one in good working order at a price you can afford, jump on it. I bought mine used in 1969 (it was my first 'real' amp) and it's still going strong. Everybody who's ever heard it loves the sound. :thumbsup::thumbsup:

    But I also never met an Ampeg amp I didn't like…so I may not be the most unbiased opinion out there.
    Last edited: Apr 30, 2016