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DI Box vs. XLR out on an amp

Discussion in 'Amps and Cabs [BG]' started by spectorbass83, Nov 22, 2005.


  1. spectorbass83

    spectorbass83

    Jun 6, 2005
    canada
    Let's say I am performing a live show and I want PA support. Will a DI box (Sansamp BDDI) work better than the XLR out on my amp?

    The same goes for recording - will a DI work better if I wanna go direct into the sound board?

    Which is better for each application and why?
     
  2. Unless the XLR out on your amp has a problem, you'll be just fine using it. IMHO, of course.

    There are some people who prefer the Sansamp sound and there are also some who think there's something inherently bad about the DI outs on amps...
     
  3. getz76

    getz76

    Apr 3, 2005
    Hoboken, NJ
    The two DI in a box and the DI on an amp have the same purpose - directly inject sound into a preamp for sound reproduction (either reinforcement or recording).

    Most likely, a DI on an amp or SansAmp is adequate for the tasks which you speak.

    Each DI is different; some have plenty of tailoring features to color your sound. Others do the exact opposite, trying to faithfully reproduce the source with little or no coloration.

    As with anything else, quality and usefulness have several variables, including cost and personal preference.
     
  4. I would prefer to ues the amp D.I but only because my sansamp (when i get it ) wont be at the end of the effects chain
     
  5. jokerjkny

    jokerjkny

    Jan 19, 2002
    NY / NJ / PA
    depends on the amp,

    i've had good and bad amp DI's. its a crap shoot.
     
  6. Some amps' DIs can't handle phantom power from the mixer (SWR for one). In that case, you'll want a separate box when there is 48v on the line.
     
  7. getz76

    getz76

    Apr 3, 2005
    Hoboken, NJ
    Good point. Don't let your Demeter VTBP-201s near phantom power, either.
     
  8. seanm

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

    Feb 19, 2004
    Ottawa, Canada
    +1 This is why I keep a good DI. I don't want to have to worry about the sound man hitting the phantom power on my line by mistake. I bought a great quality Radial Pro passive DI (couldn't justify the top of the line model for live sound) and just never worry about it. It is very cheap insurance.

    I have used the DI out on the iAMP with good results before I bought the Radial. But I do not have the Jenson transformer and I am always nervous using it.
     
  9. Hollow Man

    Hollow Man Supporting Member

    Apr 28, 2003
    Springfield, VA
    The big draws behind separate DI units are:

    a) they're small and easily portable, which makes them cake to bring along to gigs and rig up.

    b) they're easy to operate, so soundmen like them.

    c) they're generally built to handle phantom power, so there's less guesswork about damaging your gear.

    d) they have high-quality DI components (since that's the thrust of their utility), so noise shouldn't be an issue for recording.

    A lot of manufacturers cram lousy DI's into amps, just so they can say the amp has a DI and take a bigger share of the market. For a gig, it might be okay (neglecting the phantom power issue), but in the studio, a poorly made, noisy DI will stand out like a sore thumb, and can be a major hassle. Shop based on your needs. :)
     
  10. spectorbass83

    spectorbass83

    Jun 6, 2005
    canada
    You guys are helpful as always... I am gonna email peavey and ask them if the DI on my bass head can handle Phantom power..Yesterday I used the amp's DI to record and it was fine..the XLR cable got really hot though...maybe this is a sign that it cannot handle phantom power ?? The amp is in my sig.
     
  11. Bob Lee (QSC)

    Bob Lee (QSC) In case you missed it, I work for QSC Audio! Gold Supporting Member Commercial User

    Jul 3, 2001
    Costa Mesa, Calif.
    Technical Communications Developer, QSC Audio
    +1000

    If you ever plug your pre's direct out into a mixer and no signal passes through when it should, disconnect it immediately. It's a sign that there may be phantom power and the output circuitry does not like it.

    A good DI box is an important part of a pro's toolkit.

    I have two, a home-built passive one using a very high quality Triad audio transformer, and an active one made by EWI that is powered by phantom or a 9V battery.
     
  12. pickles

    pickles Supporting Member

    Mar 23, 2000
    Ventura, CA
    If you've got the Jensen transformer then its OK right?
     
  13. I've used the 201S for a number of years and we always use Phantom with no isolation to the XLR buss. No problems what so ever... has the Jensen. I believe some older models (not the 201S) did not have the Jensen. Same was true for the H series for a while.. but they fixed that.

    I also alway carry my trusty Radial JDI passive DI. This is a very handy unit. For instance my brandy new ThunderFunk amp's DI is just fine but I won't be able to have a signal that by passes the Preamp and Limiter. So.. if I want to have just my bass go into the Mixer (like most sound guys prefer) then I'll use my JDI. My 201S has a selector to select the 'post signal' but I rarely use it.
     
  14. getz76

    getz76

    Apr 3, 2005
    Hoboken, NJ
    Thanks, guys. I did not know that; I remember reading the "phantom power" thing in the Demeter "manual". :)
     
  15. jokerjkny

    jokerjkny

    Jan 19, 2002
    NY / NJ / PA
    the 201's are fine.

    its the cousin, HBP-1, people should be concerned about which lacks the jensen transformer or any protection circuit.

    btw, what about the adage:

    passive bass : active DI
    active bass : passive DI

    truism?
     
  16. seanm

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

    Feb 19, 2004
    Ottawa, Canada
    Yes, the transformer isolates the amp from the phantom power.

    I asked Radial about using a passive DI with a passive bass. I asked about the JDI since this was before the Pro came out: