DIY Microphone Preamp Plan?

Discussion in 'Archived Threads 2001-2004' started by Sathyan, Feb 12, 2003.

  1. Sathyan

    Sathyan Second Unit

    Joined:
    Jun 17, 2002
    Messages:
    298
    Likes Received:
    0
    Trophy Points:
    0
    I would like to connect 2 (i.e. stereo) microphones to my receiver. For that I need a microphone preamp which outputs line-level.

    I don't have the mikes yet so the preamp can determine whether I get XLR or 1/4" (I see more XLR options so that would be my preference).

    Do any of you have plans for an inexpensive (defined as: I can buy a mixer with 2 XLR mike pre's for $80, new) building one?

    thanks,
    Sathyan
     
  2. Jeff Meininger

    Jeff Meininger Second Unit

    Joined:
    Jun 5, 2002
    Messages:
    481
    Likes Received:
    0
    Trophy Points:
    0
  3. Ellen

    Ellen Stunt Coordinator

    Joined:
    Jan 8, 2000
    Messages:
    142
    Likes Received:
    0
    Trophy Points:
    0
    Real Name:
    Ellen
  4. Ted Kim

    Ted Kim Stunt Coordinator

    Joined:
    Apr 11, 2002
    Messages:
    214
    Likes Received:
    0
    Trophy Points:
    0
    If you are looking to build the mic preamp for the fun of it or the learning experience, then DIY is for you. However, there are a lot of used mic preamps in your price range. On ebay, you can get Bogden mic/phono tube preamps relatively inexpensively (about $20). Or you could get a newer unit from Rane or other pro manufacturers.

    Another site to check for used pro gear is http://www.digibid.com/
     
  5. I just built Eric Wallins pre-amp and it works flawless.

    easy to assemble, though there are some parts that are not explicitly layed out on the radioshack PCB. if you can semi read a schematic, it won't be hard to see where the rest hooks up (1 resistor, 3 caps, in/out RCA, LED, and toggle hookups)
     
  6. Aaron_Smith

    Aaron_Smith Stunt Coordinator

    Joined:
    Jul 22, 2002
    Messages:
    105
    Likes Received:
    0
    Trophy Points:
    0
    I would use extreme caution in doing this. Pro audio/ studio gear is built so that extreme spikes in input won't damage it; home audio is not so. The first time you bump the mic or say the letter "P" into it, you may fry your speakers or worse. At the very least you should have a compressor/ limiter between the mic preamp and the receiver.
    Just curious why you want to do this?
     
  7. Sathyan

    Sathyan Second Unit

    Joined:
    Jun 17, 2002
    Messages:
    298
    Likes Received:
    0
    Trophy Points:
    0
    Aaron -

    I want to avoid the need to replicate my CDR and Tape recording equipment which are in my hifi system. As I'm not a professional I don't want to spend hundred of dollars on recording.

    Would a cheap mixer, like the Behringer 802a, avoid this problem?

    (I believe you, but) I don't understand why a spike in input would be passed thru the line-level output.

    Right now I'm using a 1/8" mic connected to my sound card. Since the computer is on I get lots of fan noise on the recording, that's why I want to find a different way.
     
  8. Aaron_Smith

    Aaron_Smith Stunt Coordinator

    Joined:
    Jul 22, 2002
    Messages:
    105
    Likes Received:
    0
    Trophy Points:
    0
    That helps... I thought you were planning to use your hi-fi rig as a PA system; really bad idea, but you probably know that. I record in my home studio all the time, and my opinion is that you will get better recordings and have more capabilities (i.e. multitracking, editing) if you continue to use your computer. The santa cruz sound card is a pretty good one; you can get n-track software for next to nothing. Regarding the computer fan noise, I would try to either put the computer in a different room/ closet or put an isolation box around it. Computer fan noise is a much easier problem to solve then using makeshift gear for live recording.
    Any decent mic, even the cheap ones,will have XLR outputs. A cheap Behringer mixer will probably work just fine for you; if you are going to get condenser mics make sure it has phantom power.
    Lastly, this probably isn't the best forum for this information. You should do an archive search in the microphone forum over at www.homerecording.com . Lots of great advice over there. A 2 channel m-audio mic preamp and a marshall v63 will set you back about $160 and give you shockingly good results once you figure out what to do with them.
     

Share This Page