Question about Line Splitter

Discussion in 'Mixing & Song Critique' started by alfugazi, Oct 29, 2009.

  1. alfugazi

    alfugazi Active Member

    Oct 10, 2009
    What I'd like to do is this:

    I'd like to mic my amp cab and go direct at the same time for coloration. I have a Presonus Firestudio Project. I'd like to see what my options are for either purchasing a line splitter or if there is something else on the market than can achieve the same goal.

    Does anyone have a diagram of the signal flow? Im trying to wrap my head around this.


  2. dvdhawk

    dvdhawk Well-Known Member

    Dec 18, 2008
    Western Pennsylvania, USA
    What do you want the "direct" signal to be?

    Just the guitar, after a pre-amp, after a pedalboard, or after the guitar head?

    The first 3 can be achieved with a standard direct box.

    1/4" cable from guitar > direct box > 1/4" cable through to amp
    signal split to also provide > XLR to Firestudio

    The last choice, (after the amp) requires a special direct box or other interface with a much heavier transformer in it, that can take the high-output of the amp and step it down to a useable signal. It has to be made specifically for this job so it doesn't burn up the transformer or screw up the amplifier's output stage. You only need a few milliwatts to record, your amp might put out 200 watts or more.

    Good luck
  3. Kev

    Kev Well-Known Member

    Nov 13, 2001
    those DI boxes that can handle AMP-out usually have a resistive divider to knock the high voltage down to much, much lower voltage and then through the same transformer
    making it look like a normal microphone source

    if it is Line level out ... at say +4dbU ... then the transformer with be a little bigger and of similar size to other line level units

    hope that makes sense
  4. Boswell

    Boswell Moderator Distinguished Member

    Apr 19, 2006
    Home Page:
    No DI box needed for initial recording - the FireStudio Project has two instrument inputs. Just use a TS dual jack adaptor and daisy-chain the guitar lead from the amp into the FS Project. Keep the lead lengths as short as practicable.

    Re-amping is a different matter. If you need to do this, get a re-amp box that is designed to take the line out from the FS project and produce a signal suitable for the amp input.
  5. jg49

    jg49 Well-Known Member

    Oct 16, 2008
    Frozen Tundra of CT
    I used to do that all the time with an A/B box and a solid state amp w/o any problems, but when I was using the same set up and an all tube amp I was getting significant hum from the amp. Maybe it was just the use of the A/B switch instead of a Y adapter, don't know but solved it with a DI. The instrument level inputs on the Presonus work great though I noticed just a little more headroom when using the Radial J48.

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