NS2TMB 18 Volt Bartolini

Discussion in 'Pickups & Electronics [BG]' started by Luis Fabara, Oct 26, 2003.

  1. Luis Fabara

    Luis Fabara

    Aug 13, 2000
    Ecuador (South America)
    Audio Pro - Ecuador
    Hello to all.
    I have had these preamps in 2 bases, once in a DP by my request, and now in my Modulus Q6.

    Since I got my modulus, I have always had problems distorting amps when using only the bridge pickup, and have almost always used the EQ flat specially in the mids as it distorts...

    I have recently adjusted the gain trim pot in the back, and has helped things somewhat.

    My question is, how does the gain trim pot work? does it affect the input gain at the input stage of the preamp, or does it affect the volume at the output stage?

    Also, mine didnt came with an active/passive switch, and I have seen that the diagrams mention a 250K pot for volume control, while mine uses a 25K. How does using a 250K pot affect the volume/tone when in active mode. (I know a 25K pot is useless in a passive pickup situation.)

    Thanks in advance. And all the information about this circuit will be greatly apreciated.
  2. David Wilson

    David Wilson Supporting Member

    Oct 14, 2002
    Lower Westchester, NY
    well, here's the diagram from the bartolini website.


    From the diagram, and the title, looks like this preamp has a buffered input stage so that none of the usual issues with passive blending happen. Also lets you change between active and passive pickups without having to change any pots.

    The U/J-Retro preamps from John East and, I believe, the Demeter on board preamp also have this feature.

    With this, there's no easy way to incorporate an active/passive bypass.

    Someone correct me if I'm wrong, but the trim pot affects it at the input stage. The volume control affects it at the output stage.
  3. geshel


    Oct 2, 2001
    I don't know if the DB18.1 buffer is standard with the NS2TMB or not though - so check inside your controls - though I'd guess with the 25k volume you've got it.
  4. Luis Fabara

    Luis Fabara

    Aug 13, 2000
    Ecuador (South America)
    Audio Pro - Ecuador
    Yes, I have that diagram too, but my circuit doesnt have the DB18 Buffer.

    It is wired like any NTMB circuit.
  5. stflbn


    May 10, 2007
    I know this is an ancient thread, but it already deals with the NS2TMB-18 so I thought I'd just tag on here rather than starting another thread.

    I recently picked up a mid 90's Carvin 5-string with an NS2TMB-18 without the DB18 buffer. Honestly, this carvin wouldn't have space for it as it only has a single 9v battery cavity so an extra 9v is in the control cavity.

    Question #1 - can this preamp run at 9V? The gain control is backed all the way off on the preamp. As 18v it's got ridiculous gain if you turn it up much at all.

    Q #2 - What's special or different about the NS2TMB vs the other Bartolini 5-knob preamps?

    Q #3 - This specific bass also has Bart pickups in it from another bass. On the rear of the pickups it says 83RU6DC-N and -B (obviously neck and bridge). They're 2-wire and I'm assuming dual coil from the DC. Anyone have any knowledge what the character profile if these pickups may be? I think the seller said they may have came out of a Zon 6-string. They're radiused and have dimensions of 4 1/2 x 1 1/8" which i've not found examples of before.
  6. Luis Fabara

    Luis Fabara

    Aug 13, 2000
    Ecuador (South America)
    Audio Pro - Ecuador
    Hello There

    #1 No, the NS2TMB18 is a DC Coupled 18 Volt System, it was designed like this not only for headroom but to produce a lower noisefloor, as far I remember. It needs 2 batteries in there.

    #2 The DC-Coupling. http://www.bgra.net/features/active.html

    #3 Sorry, dont know about that specific pickup. As Always.. google is your friend.

    Hope that helps
  7. stflbn


    May 10, 2007
    Ya, google shows nothing on those numbers for the pickups.
  8. DaRQsiDe


    Jan 17, 2008
    Istanbul, Turkey
    Third reincarnation...

    I have a 2004 Modulus Q6 which comes with this. My question is... The wiring does not have the DB18.1 compartment.


    1- What is the purpose of the dual buffer?

    2- Without the dual buffer, what would be the difference between this and regular NTMB?

    3- I was thinking about getting Pope Flexcore for Modulus and plugging this to another bass. Would you recommend this exchange?

    Thanks :D
  9. scubaduba

    scubaduba Moderator Staff Member Supporting Member

    Dec 23, 2003
    Bump. I'd like more info on the dual buffer thing
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