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Going up to 18V in a preamp

Discussion in 'Pickups & Electronics [BG]' started by Subculture13, Mar 10, 2004.

  1. Subculture13

    Subculture13 Jamming Econo

    Apr 9, 2003
    Toronto, Ont. Canada
    I am going to be installing a preamp in my Fender 5 string Jazz bass very soon. I am almost definitely going with a Seymour Duncan STC-3M3. What advantages are there with going 18V instead of 9V? Can I just simply wire up another battery in series to do this, or is it more complicated? If it is that easy, how many batteries is the maximum it can handle, or is there really any point in going with more?

    I have heard some say that you get more headroom at 18V, but exactly what is headroom as it applies to a preamp inside a bass?

    I'll be installing it to go with my Bart's. I already have a Bart Jazz pup in it for the neck, but am going to go with the 72MV5E (MM style) in the bridge very soon and want to make sure it will do what I want. I have no problem installing extra switches or pots as needed to get it all running to make use of the tri-coil as well as the jazz pup.

    Any suggestions or opinions on this would be greatly appreciated.
  2. luknfur


    Jan 14, 2004
    Headroom usually refers to the spread between maximum output and normal operating range. Usually equates to having more power or equal output on a lower setting. Not sure regarding onboard preamps but I doubt it's any different. I know aguilar has a wiring diagram for 18v on their site but I ran an OBP 1 on 9v with no problems. I had an EMG wired for 18v and pulled one battery cause I didn't need it. Some preamps are designed for 9 and some 18 so I'd check the Duncan site. I think some can be wired for 27v. I don't know where you're getting all this space but it sounds impressive.
  3. Mike Money

    Mike Money In Memoriam

    Mar 18, 2003
    Bakersfield California
    Avatar Speakers Endorsing Hooligan
    My 9v Jazz seems to have more output than my 18v peavey G... but that might be just the pickups... maybe my G is just an active preamp passive pick up?
  4. Subculture13

    Subculture13 Jamming Econo

    Apr 9, 2003
    Toronto, Ont. Canada
    Thanks alot guys. I found a thread after I posted this that helped shed some more light on the matter too. Between that and what you al offered up I think the choice is clear that there is no point in me going to 18V, the main thing I was hoping to get was more output, which it won't. If having more headroom really only applies to major changes in the EQ, then it is not for me, I only use the onboard EQ to just tweak my settings during hte show when the stage is reacting a certain way. Beyond that my tone coems from my amp.

    As for room, my J bass still has the pickguard, so there is plenty of room to mount an additional switch or knob if need be under it.
  5. just to clarify:

    more headroom doesn't mean more output. it just means that there's more volume available, if you need it, without clipping. if you can hear the signal clipping with 9V when you slap, making it 18V may help, because there's more power available if necessary.
  6. Mario Lewis

    Mario Lewis

    Jul 6, 2001
    Clinton, MD
    What Pre can go up to 27 Volts??
  7. dmaki


    Apr 29, 2000
    I have a set of EMG's in my old bass and it used to be wired for 9v. If I played too hard it would make for a nasty tone, so I wired it to 18v and it never made that sound again. If you try wiring your bass for 18v and you don't notice that it does anything, you could always rewire it in parallel so that you only have to replace your batteries half as often.
  8. *most* EMG's are rated for 27 volts, but they say the jump from 18 to 27 is negligible.

    i say most, because i'm not sure that all of their pickups are, but they probably are.

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