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Active bass power supply ?

Discussion in 'Pickups & Electronics [BG]' started by giuseppecaporus, Mar 18, 2014.

  1. giuseppecaporus


    Dec 19, 2013
    Hi guys , I want to have a new preamp in my bass and I have this stuff :
    Preamp ( 18 V with 9/18 V switch )
    Onboard n-tune tuner (9 v with going to the jack ground )
    Db boost (only db , slap Switch,mid
    Bost) + 2 coffie Walter buffer(copy)
    (9v) . As you can se there
    Are 36v (18+9+9) , the question is .... Will it work ? If yes why ? If no , any suggestions ?
  2. frnjplayer


    Feb 3, 2014
    Currents add while the voltages stay the same. Your best bet would be to set the preamp to 9v and then a single battery will run everything. Depending on what battery life you are getting and what you need to may end up wanting to run 2 batteries in parallel which would give you the same 9V but twice as much battery life.
  3. As mentioned, voltage does not add up for every component that requires a supply. If you will be powering externally, (Which I'm assuming from the title.) you will want an 18V power supply with an adequate power handling capability for the sum of all current draws from your components. Since the total current draw from all of your components is relatively low, just about any kind of power supply will work. Just be sure it is a clean power supply, to prevent noise, and that it is designed with short protection. (Note that power supplies for this specific application are now offered by various manufacturers, as this seems to have caught on recently. These supplies are very expensive, however. Building your own should not cost much.) The supply will go directly to your 18V components, but the 9V components will need some circuit to lower the voltage. Personally, I would go with a simple LM317T based regulator circuit, set to 9.6V, as this is the voltage of a fresh 9V battery. Otherwise, an LM7809 regulator will provide exactly 9V, and not require any more than a couple of capacitors to create the regulator circuit.

    If you want to use batteries, there will be a problem with the fact that there are two voltages required. The use of a voltage regulator circuit will increase the current demand to the point that battery life will decrease significantly. This means you will have to choose another method. One method would be to add a power switch so that two 9V batteries can be wired in series, providing a 9V "tap" for the 9V components. Power switches tend to cause pops and DC offsets, however, so this is generally not preferable. Another option is to consider running all components at a single voltage. If the 18V components have adequate headroom at 9V, there will be little sacrifice in running everything at 9V. On the other hand, many 9V components can be used safely at 18V. Check into manufacturer spec sheets for info on this.
  4. Operate the preamp at 9v so everything is at 9v. An 18v pre doesn't really buy you anything. Both my active basses will take 18v but I usually operate them at 9v with no problems. With everything at 9v, the rest should be easy.

    Power your onboard electronics externally by using a TRS cable to the bass. You can use a wallwart to power everything. PM me and I can send you instructions if you're interested.
  5. bassbenj


    Aug 11, 2009
    Yes, this is what I do too. Onespot wall wart does it all over TRS. I stick to 9v to not have to deal with two voltages. As It turns out I do own a couple of 18v basses (with dual flip top battery boxes etc.) and so far with those I've just left the preamp running on batteries and used the 9 volts to run other stuff (like fretless LED markers). The problem with this is that you need to use a special bass jack that has a power switch and not the usual ground the ring terminal method (Because now you are using that to feed 9 volts to the bass) Luckily my bass already had the jack with the isolated switch terminals, but it is something to think about.