Of Pre-amps and Audio Interfaces

Discussion in 'Recording/Live Sound' started by Taller, Feb 22, 2012.

  1. Taller

    Taller Silver Supporting Member

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    I'm an old dog trying to understand today's computer recording technology, so please help me to understand this little piece of the puzzle:

    I understand that the "tape machine" now lives inside the computer, in the form of a DAW. I understand that one needs an audio interface to allow for example, a mic'd guitar amp's signal to get into the DAW.
    OK - suppose one has a really sweet analog mic pre-amp with no USB or Firewire capability - a vintage piece, perhaps. May one run the mic cable into the sweet old mic pre-amp and THEN on to the audio interface, then on to the DAW, or is this like running a pre-amp into a pre-amp?

    Thanks - :bonk
     
  2. Flogger59

    Flogger59 Member

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    That's how it's done, make sure that your interface's preamp is on Line Level.
     
  3. Rex Anderson

    Rex Anderson Member

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    Mic goes into mic preamp, comes out at line level, goes into audio interface at line level instead of mic level (some interfaces don't even have mic preamps built into them).
     
  4. Scott Whigham

    Scott Whigham Member

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    Just be aware that not all interfaces will allow you to bypass their pres. It's best to verify that first, before you buy the interface.
     
  5. Taller

    Taller Silver Supporting Member

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    Thanks for the replies!
     
  6. Tazboy

    Tazboy Member

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    The in-bound signal path looks like this: microphone > mic pre-amp > A/D converter > computer.

    The mic pre-amp and A/D converter (A/D = analog to digital) may be one unit or two separate units. The converter may in the form of a card inside of the computer or a stand-alone box (many with an USB or firewire output). The term interface can refer to the pre-amp / converter combo if it is one unit or just the converter itself. It can get a little confusing.

    If the interface has a mic pre-amp, you can skip using the outboard mic pre-amp. If you still want to use the outboard mic pre-amp, connect its line out to the line in of the interface. Be conscious of gain staging so not to overload the input of the interface pre-amp or generate excessive noise. Unless the outboard mic pre-amp has some feature or tonality you must have, I would use the built-in mic pre-amp, if present, since you are going to have to run through it anyway. It will be one less hassle and a cleaner pathway for the signal. If the interface is a converter only, it's a moot point since the outboard mic pre-amp has to be used.
     

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