what kind of microphone in acoustic guitar amp

Discussion in 'General Electronics Chat' started by lokeycmos, Mar 14, 2011.

  1. lokeycmos

    Thread Starter Active Member

    Apr 3, 2009
    im building an acoustic guitar amp. could someone please tellme what kind of microphone to use
  2. lokeycmos

    Thread Starter Active Member

    Apr 3, 2009
    this is the circuit im using. from what ive gathered there are 5 types of mics. crystal, condenser, ribbon, dynamic and carbon. radio shack has a condenser and an electret. http://www.radioshack.com/family/index.jsp?categoryId=2032266 im really not sure if impedance has a role in the mic or what kind of clarity with it. can someone please clarify?
  3. lokeycmos

    Thread Starter Active Member

    Apr 3, 2009
    anyone have any suggestions?
  4. bertus


    Apr 5, 2008

    As you say there are a lot of microphone types:
    Microphone types

    Each of the types has its own properties.

    How do you want to "mount" the microphone?
    Direct on the guitar or on a seperate stand?

    All of this can lead you to the microphone to be used.


    PS the LM386 is not a very powerfull amplifier.
    Depending on the variant the power will be between 0.5 and 1 Watt.
  5. floomdoggle

    Senior Member

    Sep 1, 2008
    Is that the little ruby? I built one, nice little practice amp. Main thing you want to look at are frequency response and direction. Uni-directional is best for musical instruments. What I saw at RS was a unidirectional dynamic would be your best bet. Run 2 eight inch speakers for the best sound on that amp IMHO.
  6. Audioguru

    AAC Fanatic!

    Dec 20, 2007
    The Ruby guitar amplifier is a low power amplifier with a Jfet input to match the very high impedance of an electric guitar pickup, not a microphone.

    Radioshack does not know anything about electronics. Their "condenser mic" is actually a two-wires electret mic that is used in the schematic you posted. Their "electret mic" uses 3 wires and your schematic must be modified to use it. They both sound very good.

    Like most mics, if the speaker is near the mic then you will have acoustical feedback howling as the sound goes around and around.
  7. Bipolar

    New Member

    Nov 8, 2009
    Is it an acoustic amp or just a mic preamp you want to build? As Audioguru has already suggested,I would definitely go for a Panasonic WM61A electret cond.mic if you want to build it as a onboard unit or as a stompbox version.It's performance is beyond belief for it's price & is freely available from Digikey,Mauser or even on e-bay!

    In it's original 2 wire mode,it doesn't work very well,but a simple 3 wire mod as described by Mr.Linkwitz,of the renouned Linwitz-Riley X'over, it sounds just amazing.You can find the mod & the preamp circuit by googling for "panasonic wm61A, linkwitz mod or similar.

    On the other hand, if you do want to build an ac.amp,then you could perhaps have different inputs to take condencer,electret or even a dynamic mic or choose the most suitable input source for you.

    I'm not sure if this is what you're looking for though!?

    PS:please buy a handful of them as you're bound to ruin a few!
    Last edited: Jun 11, 2011