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plugging a pre into an interface

Discussion in 'Recording' started by RecordingNewb, Nov 9, 2007.

  1. RecordingNewb

    RecordingNewb Active Member

    hi everyone, i have a grace 101 that i want to plug into my firepod. if i use one of the line inputs on the back of the firepod, am i completely avoiding the firepod pres? i did a quick comparison and there's definitely a significant difference when the signal is mic>grace>firepod input 1 on the front, as opposed to mic>grace>line input 1 on the back. the sound seems to be much clearer/more grace-like when i'm plugged into the back. so basically i'm wondering if plugging into the back completely bypasses any firepod coloration?
    thanks
     
  2. RemyRAD

    RemyRAD Well-Known Member

    Well, it may or may not be actually bypassing the preamp. What it is bypassing is the additional 40 DB or more of needless application.

    If you plug a microphone preamp output into a microphone preamp input you are overblowing the inputs to the preamp by plugging into the front. When you plug into the rear it may be doing nothing more than including a 20 DB pad while lowering the preamp gain structure 20 to 30 DB. And that way, you wouldn't be overdriving your first stage preamp which as you know by now sounds like total crap. Having purchased your Grace preamp is sort of like pouring perfume on a skunk. It's still awful. The resident preamp on your audio interface is probably more than adequate but your inexperience makes you grab at something you think will yield a better product because of the $you spent? Proper gain staging and microphones selection and placement will do more for your sound than purchasing expensive stuff to compensate for a lack of experience and technique. Learn how to make really lovely recordings with your existing equipment first because it's not the equipment that prevent you from making good recordings.

    But then again, it could be physically bypassing the first stage microphone preamp? It's hard to say.

    SHOW ME THE SCHEMATIC!
    Ms. Remy Ann David
     
  3. Cucco

    Cucco Distinguished Member

    Well...

    I looked for the schematic (or even a sh*tty block diagram which seems more common nowadays - which is unfortunate since in most cases it doesn't tell you where the mic preamp is - simply the gain stage...a big difference!!) and I couldn't find it.

    However, digging through the manual, I found this:

    This leads me to believe that the input is post mic-pre, pre-gain-stage.

    Therefore, the addition of the Grace could be quite welcome.

    Cheers-

    J.
     
  4. hummel

    hummel Guest

    A bit further down in the FP10 manual, it says:
    and it also states that the gain structure for the line inputs on channels 3-8 (the TRS input part of the combo jack) is:
    There is also an unofficial block diagram at: http://www.presonus.com/forums/showthread.php?t=2444

    From this, I think you should be OK to use either the line input on the back panel of any of inputs 3-8 on the front panel.
     

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