1. Please take 30 seconds to register your free account to remove most ads, post topics, make friends, earn reward points at our store, and more!  
    TalkBass.com has been uniting the low end since 1998.  Join us! :)

Behringer BDI 21: DI mode vs preamp mode

Discussion in 'Live Sound [BG]' started by Papaschtroumpf, May 7, 2018.

  1. Papaschtroumpf


    Dec 27, 2017
    I've tried to read through threads here about what the difference is between using the BD21 in DI mode vs pre-amp mode, and I'm still confused, people use terms like "mic level" vs "instrument levels" that mean little to me.

    First off, the only reason I am looking at the BD21 is that I want a cheap solution to plug into the PA (Board?) when jamming with some friends and still sounds decent.. I wouldn't have to drag my amp to work on my way to the friend's house after work, etc... I'm not worried about recording, etc... I can do that through my Eleven Rack, but I don't want to drag it with me either.

    After the reading I did, I *think* that in DI mode the bheringer simply passes my bass signal directly to the board/PA (over XLR). I think of it as a jack to XLR converter with a ground lift if needed.
    In pre-amp mode, the pedal will act similarly to the frontend of an amp and let me color the bass tone through the different knobs, on the interface, however it will still be able to be plugged into the PA/Board. That would be the prefereed mode becaue otherwise the PA may be too flat to let the bass sound good?
  2. seamonkey


    Aug 6, 2004
    The PA board usually have some gain settings themselves and can handle mic level, or line level. If you were going to run a long unbalanced line, then line level would work. Since you're running xlr balanced it won't matter. It can be adjusted at the board to take the low or high level output.
  3. s0c9

    s0c9 Supporting Member

    Jan 9, 2014
    1964 Audio artist, Fractal Audio Beta Tester
    You are OVER THINKING IT !! :)
    The DBI21 is just a DI box [for "bass"] with tone controls. There is no REAL difference between "DI mode" and "pre-amp mode". That's just marketing speak saying you can use the DI in both scenarios.

    In EITHER situation, you BASICALLY....
    • Plug your bass into the "IN" jack and run an XLR cable to the console. You can also run a [parallel] line out to your amp from the "OUT" jack if you use the DI for gigs.

    Based on my experience with other similar DI's (I own a few), the DRIVE and LEVEL controls (in combination) will control the signal level being send to the mixer.
    • Start with the mixer channel gain/trim set low. Start with BDI21 level at mid point and bring up the mixer channel gain until it's tickling the "orange" on the meters. If you can't get a good signal level on teh mixer with the channel gain kranked, back it down and increase the DRIVE on the BD121. Repeat until you get a good signal level.
    • You can now adjust DRIVE to taste. Increasing DRIVE MAY increase the signal level going to the mixer.. so you may need to back down the channel gain to compensate.
    That's about it..
    Papaschtroumpf likes this.
  4. Papaschtroumpf


    Dec 27, 2017
    Thanks, that was my undrestanding but they sure don;t make it obvious.
    I ordered it this morning.
  5. s0c9

    s0c9 Supporting Member

    Jan 9, 2014
    1964 Audio artist, Fractal Audio Beta Tester
    cool.. let us know how it goes, or if you have any issue !
  6. Domespeed


    Oct 7, 2010
    The BDI21 has a bypass switch.
    When the unit is on bypass, it acts like a normal DI without any colouring.

    I think that was meant with "DI mode".
    Philly Watts likes this.
  7. s0c9

    s0c9 Supporting Member

    Jan 9, 2014
    1964 Audio artist, Fractal Audio Beta Tester
    yeah, I could go with that and understand the confusion.
    However, "most" DI's with tone controls (and/or drive/grit) have on/off [BYPASS] switches that essentially do the SAME thing.
    I guess I "assumed" folks understood the distinction.
    Domespeed likes this.
  8. Ender_rpm


    Apr 18, 2004
    St. Louis MO
    I've had one for over a decade, and yes, this is how they work. Pedal off= clean DI, pedal on engages the pre-amp circuitry. I found the out put from the 1/4" was hotter than the XLR, and since the place I was playing only had a powered head with no input gain controls, I used the 1/4" (I was overseas). It was a decent sounding little tool, and super cheap, I still have it around somewhere, but have since picked up better DIs and pres.

Share This Page