Re: [Harp-L] On wiring mics

["Bob Maglinte" <bbqbob917@xxxxxxxxxxx>]

----- Original Message ----- 
From: "G." <gigs@xxxxxxxxxxxxxxx>
To: "harp-l" <harp-l@xxxxxxxxxx>
Sent: Friday, August 27, 2004 10:46 AM
Subject: Re: [Harp-L] On wiring mics


> <quote>
> Date: Thu, 26 Aug 2004 09:59:11 -0700
> From: Greg Heumann <greg@xxxxxxxxxxx>
> Subject: [Harp-L] On wiring mics
> 8<
> I can tell you that the Shure 520D is an exception to the rule above.
> At least the one I got - the element (made in Mex. controlled magnetic)
> has 3 wires - blue, red, black. They were wired to the built in cable,
> red to red, black to shield, and blue to black. The guy I bought it
> from had someone put a connector on the cable so I don't know how the
> mic came wired from the factory. But mine came with the black wire
> soldered together with the shield at the connector ground (as suggested
> above) - output was almost non-existant. In this case, the black wire
> should be left DISCONNECTED - it is there to allow external re-wiring
> of the mic to low impedance.
> GH
> </quote>
>
> Yep, I've got three different CM elements that came in Green Bullets that
I
> bought.
>   Two of them were simple enough, both elements US made, although
different
> model cartridges they're the same size and shape, Model 99G86AL is my
> favourite runs slightly hotter than the other model 99A86114, but
otherwise
> tonally the same.
>
> The third element I got is a Mexican made Shure CM element, Model 995556GD
> and like you describe, it has three connections, two of them are simple
> enough: red & black, the third thin blue wire is connected to another tab
on
> the cartridge.
>   It was sold to me (a fellow harp-ler :) with a fixed cable fitted with a
3
> pin XLR connector, and a handy little impedance convertor.  I tried
rewiring
> the element in different configurations to see if I could get a hot signal
> out of it, but I couldn't, although there are a few ways you can wire this
> into a 1/4" plug and get a low signal from it.  Some may remember me
asking
> about this here.
>   What I did find out is that this is a low impedance balanced mic
element,
> in the same way that the mics like the Shure SM58 is - if you wire it to a
3
> pin XLR jack thus:
>   Blue is shield/earth - wire this to pin 1 and the plug's ground - good
> idea to make sure this is wired to the mic's shell as well to ground it
> properly.
>   Red is positive signal which you wire to pin 2.
>   Black is negative signal which you wire to pin 3.
>
> Like this, you can use it with an XLR to XLR cable, and plug it into any
> balanced XLR equipment, and benefit the advantages of balanced signal (low
> noise with long balanced chords).   If you wish to plug it into an amp,
then
> its best to use it with an impedance convertor to boost the signal,  if
you
> choose to do this make sure that any cable you use is shielded properly.
> Plugged in to an amp this way the result is similar to my other CM element
> Green Bullets, though weaker - crank up the gain a bit and you can't tell
> the difference.
>
>   I've been informed by a reliable source the original US made CM elements
> were reasonably consistant in tone and strength, then Shure had their
> elements made in Mexico,  the quality of which varied somewhat.  Finally
> Shure changed to the current Mexican 520DX with dynamic element which has
> half the frequency response (100 to 5000Hz) range and a weak signal giving
> the muffled tone.   And I suspect there are both high impedance elements
as
> well as low impedance balanced elements like the ones you and I have.
> Perhaps someone who knows more about this can fill us in.
>
> -- G.
> http://www.angelfire.com/music/harmonica/ampdmics.html

Hi,
The best source for info on the Green Bullet mikes is Dave Knotts, who can
be contacted at GrBullets02@xxxxxxx and he also wrote an excellent article
on these mikes on http://www.bluesharp.org.

Sincerely,
Barbeque Bob Maglinte
Boston, MA
http://www.barbequebob.com
MP3's: http://music.mp3lizard.com/barbequebob/