Astatic JT30vc and NYC

[<Randy.Lilleston@xxxxxxxxxxxxxxxxxxxxxxxx>]

 > From: David Austin Nix <uunet!m.cc.utah.edu!David.Nix>

 > Thought I'd pass along a little frustration and a
 > remedy.  Recently I
 > purchased a new JT30vc. Can't say that I like the
 > sound alot but by hot
 > wiring in a vocal mike element from an old Shure PE585
 > it sound quite
 > rich.  The JT30vc is wired for a three prong mike cord
 > hence I plugged it
 > into a mike jack on our P.A. for a wimpy volume.  But
 > upon splicing a mike
 > three prong to an old guitar cable and plugging into
 > the same P.A. the
 > volume from the mike increased more than 5-fold.  I
 > think this has
 > something to do with using a high impedence mike (like
 > the JT30 and Shure
 > PE585) through a low impedence input.  Hence use a 1/
 > 4inch jack input for
 > the new JT30's no matter what the mike jack looks
 > like.  I wish some one
 > had clued me in on this for the band was getting
 > rather annoyed at my
 > having to raise the volume on the P.A. and the
 > inevidable hum to a nasty
 > level just to get a decent wail.

 Just because a mic has a three-prong plug doesn't mean it is low impedance,
which is the way you originally were setting it up. XLR plugs are popular
because they generally don't become unplugged accidentally, but they are no
indicator of a microphone's impedance.
  The literature that comes with an Astatics says it is a high impedance mic,
but you were plugging it into the PA with a low impedance cable. Result -
mismatched input imedance and crapola sound.
  Any decent music store should be able to sell you a high-Z mic
cable, which has a three-prong female jack at one end and a quarter-inch plug at
the other end, and then you won't have to do your own brain salad surgery on mic
cables. I use them all the time with perfectly fine results. If your PA has only
low impedance inputs, you can buy an impedance matching adaptor at any Radio
Shack store for about $15.

---Randy