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More voltage=more headroom???

Discussion in 'Pickups & Electronics [BG]' started by E.J. T.N.T., Mar 9, 2006.


  1. I have been playing a really nice ibanez SRX705 for like 3 years and i'm really pleased with it.Anyway i have been thinking of upgrading a couple of components on it(tuning keys,pickups,etc)So i've been talking about it with a fellow bassist and told me that a good mod would be running the preamp 18-volts(the stock SRX's preamp,the eqbII-DX,is 2-band preamp with a volume and a balancer pot and normally operates on 9volts).He said that the extra voltage would provide with extra headroom and when i asked whether raising the voltage would fry the preamp,he said it was safe becouse i would wire the second battery parallel(doesn't that mean that there will be no voltage increase?:meh: )So my question is:Is this mod safe and will it it have the results stated above?
     
  2. seanm

    seanm I'd kill for a Nobel Peace Prize! Supporting Member

    Feb 19, 2004
    Ottawa, Canada
    Putting the batteries in parrallel would *not* increase the voltage. It would mean a longer time between battery changes.

    It would only help headroom if the preamp was starved for current. I doubt that is the case.

    And to answer your original question: more voltage = more headroom. BUT, and there is always a BUT, many onboard bass preamps run at very little or no gain. They are there to give you active tone controls and lower output impedance. So depending on the preamp, that extra headroom is probably just wasted since 9V is signicantly higher than the possible output of the pickups.

    The 18V preamps you see where either designed for 18V and make use of it or marketing hype.
     
  3. Mrdak

    Mrdak uber bass geek baby!

    Feb 1, 2006
    Middle GA
    Hi, I know for sure that EMG pickups have a whole lot more clarity, and headroom when they are run at 18v. but when you do, you wire the batteries in series. That doesn't mean that it works the same way with your bass and eq.. you know what I mean ?
    there ia a solution.. Buy a Spector.. LOL... jk..
     
  4. chucko58

    chucko58

    Jan 17, 2002
    Silicon Valley, CA, USA
    I paid for all my gear myself. Well, me and MasterCard.
    Many amps' 'Passive' inputs will clip long before you exhaust the headroom of a single 9V battery. IMO you are unlikely to hear a difference with 18V, unless you're driving a line level device directly with your bass, and the gain is turned down on your amp.
     
  5. Your best bet is just to trial it. To do it temporarily, its just a matter of buying three cheap 9V connectors, wiring them in series (black to red), with one connector reversed (red to red, black to black). You then connect two batteries to the normal series connectors and then the reversed one connects to the connector in your bass.

    If you notice a difference, and its a difference that you like, then consider a more permanent modification (although, the mod mentioned above should work pretty well). If you don't like it, just disconnect and revert to normal.

    Everybody'll have a different opinion and for a cost of like $2 and a few minutes soldering, there's no real expense in deciding for yourself.
     
  6. EricTheEZ1

    EricTheEZ1

    Nov 23, 2004
    Clawson, MI
    I did it to my Schecter Elite-4 with EMG35Js (active) and it made it sound...a hell of a lot more active, basically. More than anything else, it just made the treble and bass controls more dramatic and harder to control. Completely unneeded.

    -Eric.
     
  7. I wouldn't use two 9Vs in series without knowing that your preamp can run safely with 18V.

    As for EMGs at 18V, I've tried both 9V and 18V, and the difference was subtle. IMO, I would only recommend running 18V if you use a lot of boost and notice clipping on the transients.
     
  8. +1
     
  9. WalterBush

    WalterBush

    Feb 27, 2005
    Yuma, Az
    Depending on the preamp design, running 18v into the circuit could fry an opamp somewhere, although it's unlikely. Unless you know in advance that a circuit is designed to take 18v, I wouldn't risk it. Besides, unless you're regularly distorting a preamp with transients, why bother?