Tobias and Bartolini buffer

Discussion in 'Pickups & Electronics [BG]' started by Flatwound, Apr 3, 2005.

  1. Flatwound

    Flatwound Supporting Member

    Sep 9, 2000
    San Diego
    So I recently got an old Tobias (1988). The pre had been changed to a Sadowsky, and since it was done in the Sadowsky shop, I figured it was wired OK. However, I wanted to try a Bart pre rather than the Sadowsky, so I got an NTMB 9v. to put in. The Sadowsky has a 500k ohm blend pot, and attached to it were two wires coming from what I believe is the original buffer in this bass, a Bartolini DTA-1. So when I wired in the NTMB, I hooked these wires to the Bart blend pot, which is 250k. Sounds great to me.

    But here's my question: before I got the NTMB, I called Bass Central and asked Grasshopper, who is apparently knowledgeable about such things, if I could get a preamp that would be comparable to the original pre in this bass, and I also asked him if the original was a TCT or what. He said that it could have been either a TCT or NTMB, but what was important was the buffer. He didn't really elaborate much except to say that Mike Tobias used Bartolini stuff which was customized specifically for him, and wasn't available to the general public.

    So what's this buffer all about? Is it really an important part of the "Tobias sound" or what?

    Incidentally, I did a search and read many of the posts having to do with buffers, and I'm still somewhat confused.
  2. IvanMike

    IvanMike Player Characters fear me... Staff Member Supporting Member

    Nov 10, 2002
    Middletown CT, USA
    best thing to do is give mike an e-mail or a call. it's not his favorite thing to do, but he keeps very detailed records of what he did on his basses. give him the serial # and he can tell you just about everything about the bass. he geve me a lot of info when i purchased my 1986 tobias some years back, and just recently helped my dealer select the right input jack as a replacement.

    just be polite as he hasnt made any $ off of that bass for 17 years now. ;)

    oh and PIX!!!!! :hyper:
  3. luknfur


    Jan 14, 2004

    yep, one of those posts was probably mine and I never grasped anything beyond a rough a idea that a buffer can either cut or boost the signal. From what I recall, DavidWilson seem to have a grasp of buffers.

    I bought a pre from a Gibson Tobias once and it was a TCT with a DTA3.1 Buffer (or 1.3 - whatever is listed on the bart site diagram). It definetly wasn't just a 1. In fact the only variation from the Bart diagram in the pre I had was it had a Gibson mid unit - but it's my understanding there were a number of other options available.

    When I stuck it in a bass I got distortion with it and after some trouble shooting removing the Buffer resolved the issue. So there either was incompatability going on or the Buffer is toaste. So I would guess that what's critical about the buffer may be in just making the thing work and not necessarily any altering of tone.

    At any rate, the preamp is history but I think the buffer's still laying around here somewhere and you can have it if you want it.

    I also had an NTMB that came with I think the same buffer (3.1 - whatever). That one did work in a bass with no problem (but it was complete and brand new too). Anyway, by that time I was yanking the pre's from my basses and turning them into outboards. With an outboard they are no pups so the buffer got pulled. To be frank, I couldn't tell any difference in tone between it installed onboard and ran outboard through the same bass and rigging. Obviously I couldn't do a side by side but any variation in tone wasn't significant enough to tell in the transition.
  4. David Wilson

    David Wilson Administrator Staff Member Administrator Supporting Member

    Oct 14, 2002
    Lower Westchester, NY
    Michael Tobias uses a buffered blend to this day in the MTD x35 basses.
    The John East U/J Retro and Demeter onboard preamps also use buffered blend.

    I'm not an EE so can't tell you the how, but it allows you to do a few things:
    1) Mix pickups of any impedance / output. You could mix active and passive if you wanted, although I've never wanted to do that personally
    2) Get a smoother, more granular, blend than that achieved with a standard passive blend.
  5. luknfur


    Jan 14, 2004
    And obviously still don't have a grasp - but this is the part I was trying to get across:

    Mix pickups of any impedance / output. You could mix active and passive if you wanted, although I've never wanted to do that personally (DW).


    since I run straight to jacks, impedance matching is irrelevant and I've run a variety of pups together - including mixing actives and passives. I can't say I've run across any combinations that work any better than typical matched pairs, although my exploration has been primarily in passing and nothing I've gone out of my way to do.
  6. mgmadian


    Feb 4, 2002
    Austin, TX
    For this reason, most blends just don't work very effectively, IMHO... slightly favoring one pickup sounds about the same to me as solo'ing it. For this reason (plus the slight tonal difference of a pot vs. a switch), I generally prefer pickup selectors.

    That said, one bass I've played which did have a gradual blend between pups was a G&L L-5500, with EMG soapbars and preamp. Maybe EMG also uses a buffered blend to achieve this?
  7. luknfur


    Jan 14, 2004


    the EMG BQC and BQS systems inclue blend pots that are reportedly specfically designed for EMG pups only - so it sounds like they work as claimed. Which I guess is an active blend. Anyway, I had a BQC control which does not include that blend and can be used with any manufacturers pups. I don't like blends either and use 2 volumes - and like being restricted to one manufacturers pups even less.

    But I think you cleared up some confusion I had over David's input on "smooth and granular" - as if I wasn't confused on buffers enough. So I'm guessing he meant gradual not granular - ey Dave?