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Dating my vintage Ampeg B-15...am I an idiot?

Discussion in 'Amps and Cabs [BG]' started by bowlingballbaby, Mar 1, 2006.

  1. bowlingballbaby


    Feb 28, 2006
    Hey Bass Guys,

    I'm new here, and could use some help with dating a vintage amp. I have an early Ampeg B-15 N Portaflex flip-top. I can't find a serial number on it anywhere. I've dug around in there, and here's what I've found to begin the dating process.

    The schematic reads "Long Island, NY, 1961". I know that's only a piece of paper, and after Ampeg moved to NJ in 1962 they might still have used to old schematics if they had them stockpiled. Yes? No?

    The potentiometer dates codes are matched at 1346207, which if I'm correct indicate manufacturer (134), year (1962) and week (07 - third week of Feb). Or is that year (6 - as in 1966) and 207 for something else? 207th day? 207 unit that year?

    The amp does NOT have the classic diamond checked tolex. It has a much more irregularly checked pattern.

    My best guess is 1962, from the pot codes.

    Have I completely missed the serial number somewhere? Is it underneath something I haven't looked at?

    Should I disassemble the trannies too and look for codes on them?

    Any help would be appreciated!

    Chris S.
  2. bowlingballbaby


    Feb 28, 2006
    Ahhh...and one more detail. Original speaker has been replaced so I can't use the date code from there. Grrrrr......
  3. Chris,

    The serial number is supposed to be:
    1- on the back of the head, where the fuse is located. That one is embossed in the metal
    2- on the inside of the cabinet on the side. That one is printed on a piece of paper glued inside.
    And both number should match.
    The serial number will greatly help the dating.

    The schematic on the tray should tell you the design date but not exactly the making date.
    On the pcb (circuit board), you should see the actual model name on the top right of it (when the knobs are toward you) and hopefully some date code.

    Hopefully the tolex is original. that could be a clue as most of the B15 had the blue check but the early ones. Let me look insde the Ampeg history book I have and will get back to you.

    How do you know the speaker was replaced? Just by the look?
    Not all B15 shipped with a square magnet speaker (just FYI)

    One more thing, look at the capacitors:
    the big one, on the inside of the head, and the can, on the outside, next to the rectifier (it is a 5U4 right?) have evolved overtime. Tell me the values (both the actual Farad and the voltage rating) and we can go from there.

    Don't you love investigation? :hyper:

    Meanwhile, check that place (if you haven't already).

    Actually if you could take some pictures of the front, back, inside of the head and the tray with schematics, we could investigate (PM me). Also some pics of the cabinet (inside and outside)
  4. Also, it cannot be a '66 as Ampeg modified the design in '65 and it became B-15NF (as shown on both the schematic and the PCB)
  5. barthanatos

    barthanatos Insert witty comment here

    Feb 8, 2006
    South Carolina
    Try flowers, and maybe some chocolate. Open the door for vintage amps. They like that.

    Sorry, couldn't help myself.
  6. bowlingballbaby


    Feb 28, 2006
    Ha....I thought about making that joke when I posted, but since I was asking for help, I thought I'd hold off. But now that the thing it out in the open....she's just finicky, this amp. I've tried everything to appease her, compliment her, bring her to important dates, but I want to see other amps as well, and she really gets jealous when I take another amp out. I'm just not a one-amp man, and she's not okay with that, I guess.
  7. Thor

    Thor Moderator Staff Member Gold Supporting Member

    Don't do all the investigation on PM, as there are others
    interested in the info as well. Like me.

    Also, on Gibsonbass.com there is a section on dating
    with potentiometers. That kind of sets the limit of 'it can't
    be older than X' as the parts weren't produced till that date.

    Hard to tell how long they sat around till they got installed though.

    Here is the Gibsonbass link:


    That one looks to be the third week of February, 1962.
    Crikey, I turned 10 years old that month, that thing is OLD!
  8. kobass

    kobass Supporting Member

    Nov 3, 2003
    Outside Boston


    Mpacificar likes this.
  9. metron

    metron Fluffy does not agree

    Sep 12, 2003
    Lakewood Colorado
    Just got the ampeg book recently but I cant recall... did the first B-15s have the random navy flair covering?
  10. SteveD


    Feb 20, 2006
    Denver, Colorado
    Hey Chris, I'm in Littleton. I know a great teacher who probably won't be in town much longer. If you want a lesson or two, let me know. Now I have to go home and check the serial number an my B15. I've had it so long I've forgotten the year of manufacture, if I ever knew...bought it used in 1974. It has the blue check covering. Great in the studio, I don't take it to gigs.

  11. bowlingballbaby


    Feb 28, 2006
    MYSTERY SOLVED. There was no serial number stamped into the back of the chassis, so I looked for other clues. A TalkBass.com member here (thanks WovenGraphite!) informed me that it should have a small piece of paper glued inside the cab with the model number and serial number. Some previous owner had installed a replacement speaker, and when they did they stapled in some extra foam padding inside the cab and they covered up the piece of paper....but... was it still there? I removed the staples and the aftermarket foam, and YES...the serial number was still in there. April 1962, Linden NJ. A very early B-15 indeed!

    Good sleuthing done today.

    Steve D...thanks for tip on the local teacher, but I'm actually a pro teacher and player myself. Not to say I couldn't get a lot better (I could), but these days I'm too busy trying to make a living to take lessons!
  12. SteveD


    Feb 20, 2006
    Denver, Colorado
    Serial # on back of my B15 is 055891. I have no idea what that means, is there somewhere to look such things up?

  13. metron

    metron Fluffy does not agree

    Sep 12, 2003
    Lakewood Colorado
    Does your amp have the tube rectifier? I looked it up in the Ampeg book and the earliest B-15 amps did have navy random flair covering. That might be what you have. Very cool! I would love to try out a nice B-15 sometime.
  14. SteveD


    Feb 20, 2006
    Denver, Colorado
    bbb: Thanks for those links. My memory was that my flipper was a 67, and that squares with the serial number.