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Anyone use Phantom Power for their NS EUB?

Discussion in 'Electric Upright Basses (EUB's) [DB]' started by Irishbass, Dec 14, 2005.


  1. After reading a previous thread about battery life on the NS series of basses I have to agree that I feel my NS CR4M is a bit severe on juice and when the batteries start to loose their life half way through a gig, you are left with the farting and flapping of a speaker cab not getting enough juice from the bass and it can be really annoying. I run my bass with an AI Clarus 1 (series II ) which doesnt have a phantom power facility. The new series III amps seem to have it but only from the XLR out. My question is does anyone else using an NS manage to run it by phantom power and if so what do you use, as most of the units you can buy such as feedback busters etc can supply phantom power to mic end connectors only. I guess in simple terms...can you buy a device that will phantom power an 18v preamp system using a regular jack to jack cable?
     
  2. I don't know of any way to run phantom power with less than 3 connectors so a standard jack won't work, but you could wire a 1/4" stereo plug to do it.
     
  3. D.A.R.K.

    D.A.R.K. Supporting Member

    Aug 20, 2003
    Virginia
    i'm sure you could have a custom job done,
    i've never seen phantom run through a 1/4" before,
    i imagine you would have to have an xlr and possibly a bit of routing
    done to accomodate the components.
    other than that, at home depot you can get a 6-pack of energizers for 9 bucks. better than buying 2-packs for 4-5 bucks.
    at this price(let's say 10.00 with tax) you could probably budget a change every 2 weeks, for about 86.00 a year, or every 3 weeks, at 51.00 a year. the batteries should easily last two weeks with a few hours of daily practice and gigs. worst case,(or best case actually), you gig nightly and change the batteries every week for a total of 173.00 a year. that's .48 cents a gig. if you need to change batteries more than once a week, i would suggest taking the bass to find out why the batteries are being drained so quickly...sounds like there might be a problem.
    just thought you might want to weigh that against customization that could potentially de-value the instrument in the long run, and cost upwards to a few years of weekly battery changes.
    cheers
    doug
     
  4. Chasarms

    Chasarms Casual Observer

    May 24, 2001
    Bettendorf, IA USA

    Exactly. I don't know if you can buy it, but you could make something that uses a TRS cable to send phantom to the bass. It'd take a little work, but it could be done easily enough.

    Many active rigs already have a stereo jack in them that is being used mono. When you insert a mono Tip-Sleeve cable into a TRS (tip-ring-sleeve) the ring and the sleeve contacts are shorted together, closing the circuit. Often this is how they have the preamp battery power down when you remove the cable. So, you may have to modify the bass very little. It could be something as simple as wiring the preamp power supply wire to the jack.

    If you wanted to get fancy, you could install a DPDT on-on switch that allows you swap between phantom and a battery.

    It'd take a little thought, and a closer look at the the circuit, but I bet it could be achieved. You may have to build a custom power supply, but that's no big deal. A small box and a couple of wall warts and you are good.
     
  5. D.A.R.K.

    D.A.R.K. Supporting Member

    Aug 20, 2003
    Virginia
    just wanted to add that a standard phantom power level is 48 volts.
    the ns pre is 18....if you decide to try a trs for power, you will probably need to add components to drop the voltage so you don't fry your electronics.
    you might want to try a post over in electronics or the luthiers corner
    for some pro-electronics info.
    cheers
    d
     
  6. Passinwind

    Passinwind I Know Nothing Supporting Member

    Take a look at the way EBS does it on the HD-350 amp. They send 9 volts on the ring of a TRS, I believe. It's not "phantom" power, but it still takes three conductors. Pretty easy to implement for someone who's handy with electronics. Lots of active basses actually use a TRS anyway, standard mike cable like Belden 8412 will work for 3 conductors, and an 18volt DC wall wart should be easy enough to come up with. One caveat though: measure the wall wart's output under load, and don't assume the nominal rating is accurate necessarily. I roll my own power supplies. ESP in OZ has nice unstuffed regulated power supply boards that could be adapted pretty easily.

    We has a thread on this in the Pickups & Electronics Forum on the other side a while ago. Regular phantom power doesn't supply all that much current, although sometimes there are ways around that. I have no idea what the current draw of an NS EUB is, but just going with something at the rated voltage is probably gonna be easier.

    I use a breakout box with my Travis Bean fretless, and I expect that my new EUB will be set up the same way. Actually, I think my bass may well be set up to just plug into a power amp, with no outboard pre necessary.

    Best of luck!
     
  7. A word of caution if you do go the stereo 1/4" jack route: remember that if you insert the jack to the socket while the phantom supply is on you'll short out the supply while the jack's on its way in (or out).

    Although you could get round that by always plugging in before you power up, I'd say such an arrangement is just asking for trouble.

    XLRs won't give you this problem of course.
     
  8. Passinwind

    Passinwind I Know Nothing Supporting Member

    Standard phantom power is current-limited such that it can tolerate shorts. But if you use some other power scheme, you'll need to be creative and/or careful to protect both the supply and your bass preamp. It's doable, but I just use XLRs for my rigs.